3.1 Assess Body Fat Burden and Health Status

Before any patient is placed on a reducing diet, where caloric intake is greatly reduced, often alongside increases in energy expenditure, medical assessment of weight, fat distribution, and health risks is essential.

3.2 Measure Body Mass Index (BMI) as an Indirect Measure of Body Fat Burden

Weight should be measured, without clothing, on electronic scales, which provide accurate weights even for heavy patients. Scales should be calibrated to ensure accuracy. Height is best measured with a wall-mounted stadiometer or against a wall rather than on beam-balance scales, which are unsteady and unreliable. Body fat is difficult to measure directly and accurately in clinical practice. Therefore, body mass index (BMI), which is highly correlated with total body fat and future health risks, is recommended as the best surrogate method of capturing body fat, although it can overestimate body fat in individuals with high muscle mass. BMI can be calculated using the following formulas (24):

BMI= (weight lbs ÷ height inches² ) x 703 or BMI = weight kilograms ÷ height meters² (24)

Table 4 presents the National Institutes of Health (NIH) classification of BMI values for adults (24). These values are based on abundant data associating higher BMI levels with higher health risks. Although individuals with the same BMI often differ somewhat in the amount of body fat they have, this is still a useful approximation that can be performed quickly and inexpensively in clinical settings.

Individuals with a BMI under 18.5 are classified as underweight, whereas those with a BMI over 25 are considered overweight; those over BMI 30 are classified as class 1 obesity, those over BMI 35 as class 2 obesity, and those over BMI 40 as extreme, or class 3, obesity. In general, the orthopedic and metabolic hazards increase with increasing BMI. Tracking changes in BMI, as well as body weight itself, are easy to use tools for monitoring body composition over time, identifying those at risk for developing overweight and obesity, and monitoring the success of those undergoing weight loss therapy.

3.3 Measure Waist Circumference to Quantify Risks Related to Body Fat Distribution

The distribution of fat on the body, as well as its sheer amount, also alters risk of some metabolic disorders. The reasons for this are becoming clear as the role of adipose tissue as an endocrine organ is more fully understood. Excess abdominal fat in the viscera, characterized by an accumulation of fat centrally (sometimes referred to as android "apple" or abdominal fat distribution or ectopic fat) is associated with greater risk of certain chronic degenerative diseases than is a peripheral fat deposition pattern (gynoid "pear" or lower body fat pattern).

Although the causal associations between certain diseases and body fat distribution are still a matter of debate (28;27), measuring waist circumference in addition to BMI is still clinically useful in assessing risk posed by body fat distribution (24;5;28-31).

Visceral and subcutaneous fat are difficult to measure accurately in office practice. Waist circumference, taken at the level of the umbilicus (belly button) with a plastic or other type of non-stretchable measuring tape, is a reasonable proxy for assessing the likely size of visceral fat deposits and the extent of abdominal obesity. Waist circumference is easier to measure and more straightforward to interpret than are waist-to-hip ratios. It is generally used as the standard in assessing central vs. peripheral fatness. The cut-points for increased risk are a waist circumference of greater than 35 inches (>88cm) in women, or greater than 40 inches (>102cm) in men (24; 31). Although the usefulness of these absolute cut-offs have been questioned due to the many possible confounding variables in their relationship with health, monitoring changes over time is advocated (32). Measuring waist circumference is most useful for defining risk in obese patients with BMI 25-35 kg/m2. Obese patients with BMIs over 35 kg/m2 already have elevated risk, so waist circumference measurements may be less necessary for them (31).

Table 5 shows how risks of weight related conditions such as type 2 diabetes, hypertension, and cardiovascular disease increase with greater BMI and waist circumference. Patients with high waist circumference may need increased monitoring and treatment of blood pressure, unhealthy blood lipid profiles, and other cardiovascular risk factors. Physical inactivity and smoking increase health risk still further. They act synergistically and apparently increase the severity of the other risk factors present as well as increasing risks themselves in other ways. Elevated serum triglycerides and lower HDL are other markers for increased cardiovascular risk that increase with high waist circumference.

3.4 Document Other Risk Factors and Comorbidities That Increase Risk and Have Other Implications for Therapy

The presence of risk factors or already clinically apparent diseases further increases the health risk of obesity over that evident with high BMI and high waist circumference alone. Table 6 describes different conditions that further add to the adverse health effects of overweight and obesity itself (24). Weight loss can help lower elevated blood pressure, blood glucose, both total and low-density lipoprotein levels (LDL), plasma cholesterol and triglyceride levels, and raise high density lipoprotein (HDL) cholesterol levels in those with abnormally high values. Other modalities of treatment, including pharmacologic therapy, may also be necessary to bring some patients into healthy ranges.

3.5 Determine if the Patient is a Candidate for Weight Loss

All individuals with a BMI over 30, and those with a BMI between 25-29.9 with a high waist circumference or one or more of the risk factors listed in Table 6, are potential candidates for weight reduction. Patients who have a BMI between 25-29.9, but who do not have any risk factors or comorbidities should be counseled to avoid further weight gain (23). The goal of weight control is both the reduction of weight and the maintenance of healthy body weight over the long term. Weight loss should be achieved through a high-intensity lifestyle intervention, which is discussed further in section 4.2, if possible (23). If the patient is not open to weight loss, at least prevention of further weight gain should be attempted. Those with very high BMIs (over 35) are unlikely to be able to achieve sufficient fat loss on a usual low calorie diet of 1,200 to 1,500 calories without regimes that must continue for many months. They should be referred for care to a multidisciplinary team specializing in obesity for treatment with very low calorie diets, and possibly pharmacology or surgery (23).

Some individuals whose weights are at healthy levels and who are without weight associated health problems also may wish to lose weight. These patients need to have their concerns about diet addressed, but should not embark on reducing diets since there are no medical indications for them to do so. They should encouraged to maintain their weight within a healthy range, and counseled to follow dietary recommendations from ChooseMyPlate.gov (Figure 1), the Dietary Approaches to Stop Hypertension (DASH) eating plan (Table 2), or the Dietary Guidelines for Americans (Table 1).

Figure 1

ChooseMyPlate.gov (F)

4.1 Assess the Patient’s Readiness and Willingness to Lose Weight

The previous sections provide the rationale for assessment of the health risks associated with obesity, the potential health benefits accruing from weight loss, and the importance of then maintaining a healthy body weight. Weight control requires behavioral change, which cannot happen without patient buy-in to the process. Therefore, the health risks of overweight and obesity need to be communicated, and patient readiness to change needs to be established. Table 7 outlines the various stages of behavior change as conceptualized by Kushner based on Prochaska’s model of behavior change, often referred to as the Transtheoretical Model of Behavior Change (6). It is important to note many patients will not progress through the outlined stages linearly, but rather will go back and forth repeatedly among stages. Therefore, timing is important and the clinician must watch for an appropriate time to bring up or follow through on the issue.

Often, those who are at highest health risk due to obesity are unaware of how serious their weight-related problems are, or are in deep denial about them. The consequences of excess weight, including long-term implications, must therefore be raised and carefully explained. Helping patients to draw connections between the short-and long-term health consequences of their current weight, and the implications this will have on things they care about, such as their family or the ability to participate in activities they enjoy, may aid in empowering patients to progress through the various stages of behavior change.

Once patient readiness and willingness to lose weight has been established, a plan of attack needs to be jointly devised with the patient. Some patients are ready to start a treatment program immediately, and the patient and counselor are able to begin setting goals together right away. Other patients have reservations or other issues keeping them from reaching the action stage needed to embark upon their weight loss goals, making it important for the counselor to address these road-blocks before moving on. For patients who are not ready to act, the issue should be deferred and brought up again at the next visit, rather than dropping the subject entirely. Some groups of patients are unable or unwilling to embark on a weight reduction program at all. Even patients who are unwilling to embark on a reducing diets may be willing to take steps to avoid further weight gain, or may be willing to work on other risk factors such as smoking cessation or increasing physical activity. These activities should be encouraged. For those who are ready and raring to go, a referral to a registered dietitian should be provided where the subject can be addressed in-depth.

4.2 Decide if Dietary Treatment is the Appropriate Option

Weight reduction with dietary treatment is in order for virtually all patients with a BMI over 30, as well as those with a BMI of 25-29.9 with comorbidities. A dietary approach to weight loss should be executed in the context of comprehensive lifestyle intervention whenever possible. This type of intervention involves frequent, in-person encounters with a trained interventionist in an individual or group setting, and incorporates a moderately reduced calorie diet, increases in physical activity, and the use of behavioral techniques to facilitate adherence to recommendations. The gold standard is a comprehensive, high-intensity, on-site program with greater than 14 sessions in 6 months, provided either in a group or individually, by a trained interventionist, and lasting for at least 1 year. When a comprehensive lifestyle intervention is not feasible, other dietary-based approaches, such as electronically based programs and commercial programs, which will be discussed in further detail later, can be appropriate alternatives (23).

For some patients, however, a low calorie (hypocaloric) diet alone may not be enough to prompt significant and lasting weight loss (34).For patients who have failed to lose on a comprehensive lifestyle program, for those with a BMI greater than 30, or greater than 27 if one or more comorbidities are present, and who are likely to have little success with a purely dietary approach on the basis of a history of many failures, other steps may be in order. This is especially important for those with class 2 (BMI>35) and 3 (BMI > 40) obesity, referral to a multidisciplinary obesity treatment team for adjunctive therapies (i.e., very low calorie diets, pharmacological treatment, and/or gastric bypass surgery) is warranted (23).

4.3 Decide if Drugs will be Useful Adjunctive Therapy to the Reducing Diet

Prescription drugs are one form of adjunctive therapy that may be considered for those with a BMI greater than 30, or a BMI of 27 and above if one or more comorbidities are present, who are unable to lose weight with dietary measures alone. Weight loss drugs are only adjuncts to, rather than substitutes for, reducing diets, however, and a reducing diet will still be necessary. Without a hypocaloric diet, drugs are unlikely to be effective. The addition of weight loss medication to a dietary-based weight loss regimen can help patients lose up to 10% of their initial body weight, with most weight loss occurring in the first six months (35). Table 8 provides an overview of prescription medications that are available. Note that none are totally free of side effects.

Many of the Food and Drug Administration (FDA)-approved weight-loss medications are approved only for short-term use (short term is usually interpreted to mean use up to 12 weeks), although some physicians still prescribe them for longer periods of time (35). Only four prescription drugs are currently approved for long-term use in weight reduction: Orlistat (Xenical^TM), Lorcaserin (Belviq^TM), Phentermine-Topiramate (Qsymia^TM), and Bupropion–Naltrexone (Contrave^TM).

Orlistat is available for both prescription (Xenical^TM) and over-the-counter at a lower dose as Alli^TM. Over-the-counter Alli^TM is available only to adults aged 18 and older, and is a half-dose version of prescription Orlistat (http://www.myalli.com) (35). Orlistat operates at the level of the gut to inhibit pancreatic lipase, blocking the absorption of about one third of fat consumed. Use over one to two years can lead to a weight loss of five to seven pounds (35). Adherence to a reduced calorie diet with less than 30% calories from fat is necessary while on either Orlistat or Ali. Both Orlistat and Ali’s disadvantages include fat malabsorption, sometimes accompanied by anal leakage, and decreased absorption of fat-soluble vitamins. Because of this decrease in fat-soluble vitamin absorption, patients taking either version of the drug should be advised to take a multivitamin supplement containing fat-soluble vitamins to ensure adequate nutritional status (35). Dietetic counseling is helpful in managing weight loss.

Lorcaserin (Belvique^TM) is another weight loss drug approved for long term use and is available by prescription only. Studies evaluating its effectiveness found that 47% of those who used the drug lost at least 5% of their initial body weight (35). Qsymia^TM is another long-term weight loss drug that was approved by the FDA in 2012. Qsymia^TM is a combination of an appetite suppressant, phentermine, and a seizure medication, topiramate. Studies found that after 1 year using the recommended dose of the drug, 62% of patients lost greater than 5% of their initial body weight (35). ContraveTM is the newest long-term drug to treat obesity, and was approved in September 2014. ContraveTM is a combination of bupropion, an antidepressant, and naltrexone, a medication used to treat alcohol and opioid dependence. Studies showed that after 1 year, 42% of the non-diabetic patients tested lost at least 5% of their initial body weight. (36). With all long-term weight loss drugs, if at least 5% of initial body weight is not lost by 12 weeks, use of the drug should be discontinued as it is unlikely to be effective later, and therefore the risks outweigh the putative benefits (35).

Phentermine (Suprenza^TM), phendimetrazine (Adipost^TM), diethylpropion (Tenuate^TM), and benzphetamine (Didrex^TM) are modestly effective prescribed anorectic agents approved for short-term use (12 weeks in a 12 month period) by the Food and Drug Administration (FDA) (35). Phentermine and diethylpropion are widely prescribed, as they are relatively inexpensive (approximately $30 for a one-month supply), and provide slight stimulatory effects. However, little research has been done on their long-term side-effects (39).

The off-label use of bupropion (Wellbutrin^TM), a drug originally approved by the FDA for aiding in smoking cessation, has become popular in the past few years for weight control. Bupropion enhances norepinephrine and weakly blocks dopamine reuptake and is being studied for the treatment of obesity. Bupropion could be considered if a patient presenting with obesity wanted to quit smoking as well and lose weight (38). Short term side effects most often reported are agitation, dry mouth, insomnia, headache, nausea, constipation, and tremor. However, its long-term effects on weight loss are not clear, and its use must be accompanied by a low-calorie diet if it is to help in weight loss.

Topiramate (Topamax^TM) and zonisamide (Zonegran^TM) are anticonvulsants that were originally approved to treat epilepsy. They are also sometimes used off-label for their weight-loss effects. However, adverse effects have also been reported, most commonly difficulty with memory, parathesia, difficulty concentrating, and mood problems. These drugs are approved by the FDA for epilepsy only, and not for weight loss (38).

Metformin (Glucophage^TM) is a diabetes medication that may promote small amounts of weight loss in people with obesity and type 2 diabetes. One study found that patients treated with metformin for diabetes lost 2kg more at 6 months compared to placebo, and maintained at 1 kg at 4 years follow-up. It is unclear, however, if weight loss on metformin is related to improved glucose tolerance or the drug itself (40).

Byetta^TM (exenatide) and pramlintide are sometimes used in treating the comorbidities of obesity. Both compounds affect the gastrointestinal hormones that regulate glucose homeostasis, gastric emptying, and satiety. Exenatide (Byetta^TM) is used as an adjunctive therapy for improving glycemic control in patients with type 2 diabetes who also take metformin or sulfonylurea. Pramlintide is an adjunctive therapy for patients with type 1 or type 2 diabetes who use insulin at mealtimes. Usually patients with diabetes gain weight with better glucose control, however, with these drugs, better blood glucose control is often associated with weight loss, at least in preliminary studies. The most common side effect of these medications is nausea (38).

Major disappointments have resulted as research on the once promising class of drugs known as cannabinoid (CB1) receptor antagonists has continued. Rimonabant (Acomplia^TM) was the first CB1 receptor blocker approved for use in the world. Its suggested use was for patients with a BMI of 30 or more, in conjunction with exercise and diet, to aid in weight loss. CB1 receptors are located in the brain, gastrointestinal tract, adipose tissue, heart, pituitary, and adrenal glands, and if they are stimulated, these receptors increase appetite. Blockage of these receptors is thought to decrease appetite. However, the FDA ruled that Rimonabant carried too much risk to be approved for use in the United States, with side effects including nausea, anxiety, diarrhea, and depressed mood that, in severe cases, led to suicide (38). In 2009, the European Medicines Agency (EMEA) also concluded that the benefits of Rimonabant no longer outweighed the risks, and marketing authorization for the drug in the European Union was officially revoked (43). Investigation into the cannabinoid (CB1) receptor antagonist class of drugs has since ceased (39).

Other areas of research for future weight loss drugs include drugs combining appetite suppressants and those that affect addiction, drugs affecting gut hormones that influence appetite, drugs that work to shrink the blood vessels supplying fat cells, drugs targeting genes associated with obesity, and manipulation of gut bacteria (35).

Sibutramine (Meridia^TM) was a commonly used obesity drug first introduced in 1997. However, it was voluntarily withdrewn from US markets by its manufacturer in 2010 after clinical trial data indicated that the drug increased the risk for heart attack and stroke. It should not be prescribed or used for the treatment of obesity (44).

Some of the surprisingly positive effects with weight loss drugs are due the fact that the medications are not what they seem to be but rather adulterated and contain undeclared drugs. The FDA releases an extensive list of tainted weight loss products, many of which contain undeclared drugs (Table 9) (44). If patients are taking any of these contaminated products, they should be advised to stop immediately. Table 9 provides a comprehensive list of these tainted products on the market from 2011 onwards, along with the undeclared pharmaceutical/chemical included in the product. There are also other drugs that may be added although they are no longer available for distribution through legitimate sources because of adverse and sometimes fatal side effects including Fen-Phen^TM, Redux^TM, Pondimen^TM, fenfluramine, Meridia^TM, and dexfenfluramine.

Drugs for weight loss are of limited efficacy, some patients cannot afford them, and all of them have side effects. About one fourth of all individuals who are prescribed medications will not have the expected response (39). Patients who are likely to respond to drugs tend to do so within the first month of therapy. If they fail to lose four pounds (1.8 kilograms) in the first four weeks, the drug is unlikely to be effective, and it may be appropriate to discontinue its use. A loss of four pounds within the first four weeks generally predicts weight loss of at least 5% body weight by six months of therapy, if the diet and drug continue to be used (39).

Dietary supplements purported to be helpful in weight loss are discussed in section 9.7.3 (Dietary Supplements and Weight Loss). No supplement currently on the market is both safe and effective for weight loss.

4.4 Rule Surgical Options In or Out

Surgical options such as adjustable gastric banding, or more invasive techniques such as rou en y gastric bypass,, sleeve gastrectomy or biliopancreatic diversion with duodenal switch surgery are recommended only for patients classified as Obesity class 2 or above (BMI>35), or as Obesity class 1 (BMI >30) with comorbidities (23). Patients who opt for the surgical route must adhere to certain dietary recommendations before the surgery is performed to show they are able to follow a hypocaloric diet. After surgery, food intake is altered and meals must be smaller because gastric capacity is considerably limited (46). Patients will be required to adhere to a strict, multi-stage diet post-surgery to heal and adjust to new gut physiology short term, as well as to promote weight loss long-term. A post-operative weight reduction surgery diet used in one hospital is shown in Table 10, but there is no standard, widely accepted protocol for diet therapy post-bypass at present. Dietary restrictions must continue indefinitely after surgery to prevent weight regain, and patients will require lifelong use of appropriate vitamin and mineral supplementation to prevent deficiencies. Failure to adhere to a hypocaloric diet through such strategies as consuming large amounts of alcoholic or sugar sweetened beverages, melted ice cream, and many small but calorically dense meals will result in weight and fat gain.

While data suggests that bariatric surgery is more successful than non-surgical interventions, in promoting greater long-term weight loss and inducing initial remission of type-2 diabetes, there is a lack of evidence assessing the long-term risks, complications, and costs of bariatric surgery (238). It is important to note that post-surgery, patients are at risk for many nutritional deficiencies, which can negatively impact overall health, even in the context of weight loss. In one recent study that followed patients who had lost weight more than 50 lbs prior to body contouring procedures, those that had lost more than 100 lbs were more likely to suffer complications, with the effect being greater in those who had lost over 100 lbs from bariatric surgery compared to non-surgical means. Among patients who had bariatric surgery, the risk was highest for those who had had gastric bypass, and lowest in those who had has a lap-band or gastric sleeve (239).

Note: Post Gastric Bypass Surgery Diet Used in Tufts Medical Center is adapted with permission from Melissa Page, MS, Rd, LDN, Weight and Wellness Center, Tufts Medical Center, Boston, MA.

There are many tools available to practitioners to aid in accessing obesity and its related health risks, as well as in determining appropriate treatment options. One such tool is the American Society of Bariatric Physicians Obesity Algorithm (292). Another useful tool is the algorithm in the “2013 Guideline for the Management of Overweight and Obesity in Adults,” which was created by the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and The Obesity Society (23).

5.1 Clarify Reasonable Goals

In 1998 the National Institutes of Health (NIH) issued guidelines recommending that healthcare professionals advise obese patients to lose weight. Evaluating the effect of these guidelines somewhat later, one study examined the proportion of obese patients and those that actually received advice between 1994 and 2000. The proportion of patients that were obese and received advice to lose weight from physicians during routine medical check-ups decreased from 42.3% in 1994 to 40.3% in 2000. Among those that did receive advice to lose weight had 2.8 odds of trying to lose the weight opposed to those who did not receive any advice (48). In addition to the NIH guidelines, in 2003, the U.S. Preventative Services Task Force (USPSTF) recommends that clinicians screen all adult patients for obesity and offer intensive multi-component behavioral intervention to those affected individuals. Primary care physicians play a critical role in screening adults for obesity and providing appropriate treatment (49). Even with these national recommendations and guidelines, it is still a challenge for healthcare providers to manage obesity (50). Another challenge is who is to pay for it, since many insurance plans do not, and many of those who are obese do not have the money to pay for treatment out-of-pocket. In 2009, less than 50% of obese patients received weight loss advice from physicians, citing many barriers to counseling and intensive treatment of obesity (50). This study concluded that there is a general lack of consensus about the best approach to weight loss; however, this can be improved if counseling skills are developed early during training of physicians in treating obesity (50).

As demonstrated in the study mentioned above, those patients who received advice to lose weight were almost three times more likely to attempt weight loss, so it is important for health professionals to discuss weight loss with their obese patients. The approach used by health professionals when treating obese patients and helping them to set goals is most effective when it is non-judgmental, respectful, and empathetic. This allows patients to feel comfortable with discussing their weight. The focus should be on an acceptable weight to achieve better health outcomes rather than simply reaching a lower body weight (51-53). Furthermore, health professionals must always keep in mind that overweight or obese patients might be hesitant to broach the topic of weight loss, but indeed want assistance in discussing, setting and achieving weight loss. By speaking and working with patients as partners in reaching their weight goal, health care providers can play a big hand in improving their patients’ health.

Understandably patients do not like the terms “obesity,” “fatness,” or “excess fat,” and are more receptive to terms such as, “weight” and “excess weight.” It may be difficult for health care providers to bring up the topic of weight loss, but for more tips and advice, healthcare providers can visit The National Institutes of Health’s Weight Control Information Network (WIN) at http://win.niddk.nih.gov/publications/talking.htm for more information on discussing obesity with patients and for some examples of how to bring up the topic of weight loss with patients.

Determining whether a patient is motivated to lose weight is pertinent and the first order of business, since patient involvement and investment are essential for weight loss success. If a patient is not ready to engage in weight loss, discuss the importance of weight maintenance and physical activity at visits until the patient is ready to begin weight loss therapy (24). Once the patient expresses the desire to lose weight, determine the patient’s weight-related goals and ascertain that goals are realistic and attainable. Agreeing on realistic goals facilitates maintenance of weight loss (54). Unrealistic goals should be discussed and made into more achievable ones. Additionally, patients need to be reassured that the counselor, or healthcare provider, is interested in their health as individuals. Providers should not assume that all of their obese patients’ health problems are weight-related (55), nor should they fail to treat these other problems even if the patients refuse treatment for the obesity. The health care professional’s job is to reduce health risks and improve quality of life to the greatest extent possible within patients’ wishes (56).

On their own, patients often choose to lose weight using drastic measures, such as fasting or very, very low calorie diets, to get fast results even though there is no evidence that they are the best for losing weight. Healthy weight loss is key for long-term weight maintenance (54;57). Intensive, very low-calorie diets (VLCDs; e.g., ≤800 calories per day and especially <500 calories) produce significantly greater initial weight loss, however, these results are often not maintained over time (58). In a study done in 2008, participants were enrolled in a program designed to help maintain weight loss. Participants all initially lost weight using one of three methods, VLCD, commercial programs or a self-guided approach. At the start of the study, those who had used a VLCD lost up to 24% of highest body weight in the last two year compared to those in the commercial programs and self-guided approaches who lost 17%. Results showed that those who used a VLCD regained significantly more weight than the other two groups by six months in the weight maintenance program. However, those who had lost weight using a self-guided method were able to maintain their initial weight loss with great success (58). It should be emphasized that the primary reason for losing weight is for better health outcomes; therefore, weight loss should occur by using healthy methods, ones that can be maintained throughout life. Concentrating on improving health outcomes and other risk factors rather than simply on weight loss is vital.

Once it is established the patient is motivated, health professionals should begin by working with the patient to set realistic, achievable, and sustainable weight loss goals (57). From the medical perspective, an ideal weight goal is one that will maximize heath related effects while minimizing disruption to the patient’s quality of life. This allows the patient to incorporate dietary changes into daily life and therefore incorporate them into their lifestyle to maintain weight loss. Physicians have access to measurements of weight-related risk factors that will be improved if weight is lost. Therefore they are uniquely qualified to define and communicate what a "healthier" weight should be for the patient. Nurse practitioners, registered dietitians, physician assistants, and others should reinforce the message the physician gives, and carry out the actual therapy.

There is no single target weight that will meet every one’s goals. Optimal weight reduction targets vary depending on the patient’s weight and co-morbidities. Progress toward healthier weight goals should involve a gradual approach that minimizes health risks and is timed to the patient’s level of readiness. Excess emphasis on aesthetic and cosmetic aspects of weight loss should be avoided. Most patients may have unrealistic ideas of how much better they will look with weight loss so it is important to stress the health advantages of even modest weight loss (i.e. a half-pound per week) (59). While some cosmetic improvement is possible with a weight loss of five to ten pounds, it rarely meets the patients’ expectations, which can be discouraging. Patients need to have a realistic weight loss target set for themselves, which they have developed during counseling session with a health professional. In time, greater weight loss may be possible if realistic goals are adopted, met, and sustained. The aesthetic and cosmetic effects of weight loss are "extra benefits." The primary medical concern is to help the patient lose enough weight to improve or maintain his/her health.

5.2 Adopt Realistic Goals that Include Health Objectives

A healthy target for loss is usually to achieve a weight loss of one-half to two pounds of body weight each week over six months (24 weeks), leading to a decrease of 5 to 10% in body weight from baseline. For example a 250 pound, 5’6’’ woman with a BMI of 40 that lost 12.5 pounds over six months, would have a 5% weight loss, and an ending BMI of 38.5. A 10% weight loss would result in a BMI of 36.3. The goal is to maintain this weight loss over time, and that is never easy. A weight loss of 5 to 10% is achievable and moderate enough to decrease some obesity-related risk factors, such as type 2 diabetes, hypertension, cardiovascular disease, and sleep apnea (9).

The recommendation of dieting for six months rather than a longer amount of time is a practical one because after about six months, most patients have great difficulty sustaining adherence to any diet, particularly if it is very rigorous. Weight plateaus as energy intake fluctuates and resting metabolic rate and energy output decrease. After six months of weight loss, patients should focus on maintenance of the weight loss through a combination of diet therapy, physical activity, and behavior modification. If successful, after several months they can start a weight loss cycle again. When patients do not engage in a weight management program that includes all three components, the risk they will regain all or some of the weight increases (57;60). Most individuals regain one-third of their lost weight in one year, and nearly half return to their original weight within five years (54). The more frequently a patient has contact with his/her health care provider, the weight loss and maintenance outcomes tend to be more successful (57).

5.3 Define Successful Outcomes for Weight Reduction with the Patient

Patient weight goals depend on their motivation and their perception of health risks, in addition to other aspects of their lives unrelated to health outcomes. Some patients simply are not motivated to lose weight, or they may be motivated but unwilling or unable to make any changes at present. It is unreasonable provide an unmotivated patient a weight loss goal that they do not wish to achieve. Instead it would be beneficial to come to an agreement about the steps the patient is willing to take to begin to improve their health. One of the newer techniques used in counseling is “motivational interviewing” (MI); an egalitarian, empathetic approach to counseling. It uses specifics strategies, such as reflective listening, positive affirmation, and agenda setting to engage the patient in health behavior changes that will facilitate weight loss. The goal in MI is to assist individuals to work through their ambivalence about behavior change and to find what motivates them internally. Patients understandably often have strong aversions to the weight loss process, so MI counselors reflect the patient’s doubts and work through those with the patient. The process also provides opportunities for the patient to voice concerns about remaining overweight or gaining even more weight, which might serve as motivation to begin losing weight or gaining more control of their weight. MI can be more effective than the counselor simply stating facts to counter the beliefs and doubts of the patient and often enables patients to develop their own reasons and plans for change. Individuals are more likely to accept and act upon their own choices and opinions when they voice them themselves (30).

For patients who are already motivated, the weight loss process can begin much faster because the patient is already willing to make changes. However, it is important to check what they think they will accomplish and when. Their patients’ weight loss targets are often unrealistically low and their time frames unrealistically short (e.g., targets of 25% or more of body weight in a few weeks rather than many months). Numerous studies have shown that obese individuals hope to lose 25 to 35% of their initial weight within a year or less after beginning obesity treatment. Realistically, patients lose only 5 to 15% of their initial weight over a year after beginning any kind of obesity treatment. Unfortunately, many dieters still maintain unrealistic standards even when they are repeatedly informed that their goals may be unrealistic (61).

For example, in one recent assessment, the before-treatment weight loss goals of 45 obese women were assessed, and the women were randomized into a behaviorally based weight-loss program over 48 weeks. While 8 to 10% of weight loss would have been a success from a medical perspective, the women identified a loss of 32% of their body weight as ideal. At the conclusion of their 48-week treatment, the women lost an average of 16% of their total body weight. Even though their weight loss was more than medically expected, the women collectively considered this loss to be “disappointing” (54). This study illustrated how most patients’ ideal weight loss goals are unrealistic and often two to three times what most patients achieve (62). For these types of patients, counseling on more realistic targets and time frames is helpful.

Because patient weight goals are often very different from those of their healthcare providers, health professionals must clearly understand patient expectations for treatment and understand the rationale behind these patient expectations. It may be necessary to work with the patient to re-evaluate changes in expectations over the course of treatment (54). Providing patients with verbal and written information on how much weight they can expect to lose with obesity treatment is helpful in communicating and setting realistic weight loss goals (61). When patients’ ideals of drastic weight loss are not met within their preferred time frame it leads to disappointment and frustration, so these dramatic goals must be addressed at the onset of treatment. It is also important to praise patients once they begin to make positive behavior changes. It helps them feel as though their efforts have been acknowledged and motivates them to maintain their new habits and continue to lose weight or stop gaining more weight. Health professionals should be sure to frequently remind their patients of the health benefits that a 5 to 10% weight loss will offer.

5.4 Define Dieting Success in Broader Terms than Weight Loss Alone

Definitions of success are always patient-specific, but health professionals should emphasize the importance of health outcomes rather than how the patient would like to look as their definition of weight loss success. The definition of successful obesity treatment includes goals other than weight loss, and these broader health goals need to be communicated to patients. The reduction of risk factors and co-morbidities, even if weight is not lost, is a "success" from the health standpoint. For some patients, prevention of further weight gain after years of a slow, steady increase in weight is “progress.” The maintenance of a reduced weight, even if it is still within the range of obesity as clinically defined, is also a "success". Some outcomes to focus on include improved metabolic profiles such as, lower blood pressure, serum cholesterol, or fasting blood glucose. The following health behavior changes also denote success: increased daily physical activity and fitness; greater healthfulness of eating patterns, such as more consumption of fruits, vegetables and fiber; and reduction in dietary fat. Changes in specific unhealthful habits such as smoking, or overindulgence in alcoholic beverages, are also reasonable measures of success that may help enhance self-esteem, self-efficacy, quality of life and functional capacity (24;5).

5.5 Set an Individualized "Healthier Weight" Target with the Patient

Patients can be unreasonably hard on themselves and fear that losing weight requires drastic measures. An initial healthy weight goal of 1-2 BMI units often requires much less extreme measures than patients think. For example, a 5’4’’ woman weighing 250 pounds with a BMI of 43 losing 5% of her body weight, or 12.5 pounds, will have an ending BMI of 41. This amount of weight loss could take up to 25 weeks, if she loses one-half a pound per week. Weight loss of one-half a pound to two pounds per week is reasonable and offers the best chance for long-term success, but for extremely heavy people, this may take many months or years. However, as mentioned before, weight loss of even 10% of initial body weight, if sustained, significantly reduces risks of coronary heart disease and other co-morbidities (9;63). Obese patients often expect to lose 25% to 35% of their initial weight over the first year of obesity treatment. Dieters often maintain these expectations even when they are repeatedly informed that their goals are likely unrealistic —even with pharmacological treatment, so the message needs to be repeated (61).

5.6 A Reasonable Target: 10% Loss of Body Weight over 6 Months

A 10% weight loss target can be achieved in most patients with a caloric deficit of 500 to 1,000 calories per day, leading to losses of one pound to two pounds per week. For women, a weight reduction plan of eating approximately 1,000 to 1,200 calories per day is suitable. According to the National Institutes of Health and the National Heart, Lung, and Blood Institute, a 1,200 - 1,600 calorie allowance for men or women who weigh 165 pounds, or more, and who exercise regularly is recommended. These calorie amounts along with increased physical activity and behavioral modification will likely produce a caloric deficit to achieve the targeted weight loss plan of one to two pounds per week (64).With a caloric deficit of 500 to 1000 calories per day, if followed with perfect adherence, after six months, weight loss of 26 to 52 pounds would be expected. However, in reality, losses are usually between 20 to 25 pounds, since adherence is never perfect (65).

A decrease of one BMI unit usually represents a loss of 10 to 15 pounds, but the exact amount depends on height and weight. A decrease in two BMI units over six months is another way of stating a weight loss goal. Reductions of this magnitude in weight usually decrease several weight-related risk factors such as blood glucose and blood pressure, which should result in better overall health. In addition, patients’ clothing is likely to fit better and their appearance should be trimmer. If further weight reduction is necessary after 10% of initial body weight is lost, it can be attempted with an increased calorie deficit after prior weight loss has been maintained for several months. Medical nutrition therapy for obesity should last at least six months or until weight loss goals are achieved. After that it is vital to begin a weight maintenance program that includes the same three components used for initial weight loss, diet, physical activity, and behavior change to help prevent weight regain and maintain the patient’s new, healthy lifestyle (57). In addition, the patient should have a strong social support network of encouraging friends and family, and/ or participate in a group where others are also undergoing weight loss treatment. With a strong social support network it is easier for patients to continue his/her healthier lifestyle (66).

5.7 Set an Increased Physical Activity Goal

Physical activity is important in weight loss. Physical activity and exercise are not synonymous. Both are desirable but the first is essential. If left on their own, most dieters become more sedentary during weight loss, especially if diets are very low in calories. This is because a markedly negative energy balance reduces exercise tolerance, the body’s maximal power output and increases the body’s sense of perceived exertion (67). Therefore, conscious efforts to increase physical activity while dieting should be attempted. However, physical activity alone, without a reduction of calories, only induces modest reductions in body weight. Few studies to date have incorporated enough physical activity to achieve even a 5% weight loss using a physical activity intervention alone. When physical activity is paired with energy restriction, it has a synergistic effect on weight loss. Despite its modest effects on weight loss, physical activity is also essential for improving health-related outcomes relevant to many obesity related co-morbidities (e.g., heart disease, type 2 diabetes, and possibly some cancers)(68). Physical activity is also vital in preventing weight regain and may enhance quality of life (69). There is a strong association between physical activity at follow-up and maintenance of weight loss. Data from the National Weight Control Registry, a registry of more than 3,000 individuals who have successfully maintained at least a 30-pound weight loss for a minimum of one year, shows that 90% of the individuals report that physical activity is crucial to their long-term weight maintenance. They report expending, on average, 2,700 calories per week in exercise, the energy equivalent of walking four miles seven days a week (70).

5.8 Individualize the Diet and Treatment Program

Evidence-based reviews of successful weight control techniques increasingly emphasize the importance of individualized, multidisciplinary care in addition to realistic goals that are focused on health-outcomes and making permanent lifestyle changes, including an increase in physical activity (65;71).

The specific factors that induce a chronically positive energy balance differ among individuals. Daily lifestyle, environment, resources, and social situations may vary considerably. Weight loss strategies must, therefore, be individualized in order to promote adherence and success (5). No single diet works for everyone. Different dietary approaches for maximizing adherence are successful to varying degrees in different individuals. If asked, patients can usually identify some strategies that have worked for them in the past and health professionals can build a program starting with these strategies as starting points. Previous pitfalls can also be identified and the new weight loss strategy can be tailored to avoid them. Candidates for weight reduction should discuss the approach that best suits their needs with their physician, dietitian, or other health professional. In addition to energy content, individual food selections, meal frequency and many other factors can be tailored to make the diet better suited for the individual. Some factors to consider include the diet’s cost, convenience, how it approaches treatment of co-existing health conditions, and whether it assists patients in adopting strategies for healthful life-long weight maintenance (72;73).

Many overweight patients have already tried many times to lose weight on their own. For example, in the United States 50 – 70% of US adults are trying to lose weight (74). Self-directed efforts are usually motivated by aesthetic or social rather than health-related reasons. The goals they adopt are often unrealistically ambitious, the information they obtain on weight management is often inaccurate, and the motivation and support they receive is often inadequate. Solo efforts often fail and lead to discouragement and a sense of futility (75). The vital role of health professionals is to provide motivation, information, counseling, and support for patients to be successful.

Throughout weight loss patients must be counseled on sound eating patterns. Some dietary education topics that should be discussed to help them are listed in Table 11. The National Institutes of Health (www.nutrition.gov), the American Dietetic Association (www.eatright.org) and other organizations, provide materials, checklists, guidelines, menus, and recipes to assist in such patient education (4;48). Resources for health professionals and for patients can also be accessed at websites such as myplate.gov, the American Heart Association (http://www.americanheart.org/), American Diabetes Association (http://www.diabetes.org/), the American Cancer Society (http://www.cancer.org/), and the American Dietetic Association (http://www.eatright.org/).

Patients should maintain daily records of their food and beverage intake; this helps to cue them to restrain themselves, and also the record is a visual reminder that it is important to watch one’s intake. Some may also wish to include their mood at the time they ate in order to help in recognizing reasons for eating beyond hunger. Record keeping often increases awareness of consumption, and promotes dietary adherence. Patients should be encouraged to review food records each week and to identify any patterns related to eating and behavior that they can work on for the next week.

6.1 General Principles

For an individual already overweight, successful weight control first requires a hypo-caloric phase during which dietary intake is decreased while energy output is increased (or at least not decreased). This phase is referred to as the ”weight loss” "energy deficit" or "hypo-caloric phase" of weight loss.

The essential components of weight loss, regardless of type of diet, are decreased energy intake, increased energy output through physical activity, behavioral modification and alterations in the environment that foster all of these measures. Although this chapter focuses on dietary measures in the treatment of obesity, all reasonable weight control programs should also include physical activity and behavioral modification.

6.2 Size of Caloric Deficit Needed to Lose Weight

Obesity results from the accumulation of excessive body fat, which is stored as adipose tissue. An energy deficit of approximately 3,500 calories is required to lose one pound of fat. However, there are several factors that can influence this particular number. These include compensatory changes in resting metabolism, the energy cost of work, and discretionary physical activity, which can sometimes alter this figure by 100 to 200 calories. Over the long-term, this relationship of 3,500 calories per pound of fat holds up quite well. Thus, it is the size of the energy deficit between basal energy needs and the energy output that determines the slope of decline in adipose tissue over time. How well this energy deficit is maintained throughout the weight loss period is dependent on a multitude of factors (76). In addition, creating a calorie deficit using this rule of 3,500 calories per pound may not be applicable to everyone. Work by Dr. Kevin Hall has shown that initial body fat as well as the magnitude of weight loss can influence the applicability of this rule (76).

As previously mentioned, a reduction of 500 to 1,000 calories per day is recommended to achieve a weight loss of approximately one to two pounds of body weight per week (i.e. -3,500 to -7,000 calories total). Cutting down on alcohol, dietary fats and/or sugary caloric carbohydrates is a practical way to produce this deficit (70).

6.3 Goal of the Energy Deficit Phase

The goal of dietary treatment of obesity during the weight loss (energy deficit) phase is to decrease body fat stores without unduly depleting lean body mass or otherwise compromising health. Lean body mass includes skeletal muscle and vital organs. During weight loss, some lean muscle tissue is always lost in combination with the fat loss, but the goal is to keep this loss to a minimum (64). While weight is shed, body stores of other nutrients such as water, vitamins, minerals and electrolytes must be maintained. Fortunately, dietary strategies are available to minimize loss of lean tissue and other nutrients.

A systematic review found that increased lean tissue is lost if the energy deficit of the diet is too large in combination with rapid weight loss. In contrast, inclusion of exercise (both cardiovascular and resistance) and adequate dietary protein (60 grams per day, ranging from 0.8 g - 1.5 g per kg of body weight) helps to minimize lean tissue loss (73). These dietary strategies should be incorporated into dietary treatment plans to minimize lean body mass reduction and maximize fat loss.

7.1 Keep Food Records: Food Intake Varies from Day to Day and it is Easy to Forget to Diet Every Day

People vary in their eating patterns from day to day. Weight reduction prescriptions are such that the patient should aim for a caloric deficit of approximately 500 calories per day, which would achieve weight loss of about one pound per week. This can seem like somewhat of an abstract since the patient may not know how many calories he/she is eating in the first place. Since most people vary in their food intake from day to day, they have difficulty recognizing if they are eating less than they were previously. For this reason, simply urging patients to "eat less" of certain foods in general, is unlikely to produce clinically significant weight loss. Specific advice is more appropriate and easier for the patient to achieve. Examples of specific actions that decrease caloric intake include, cutting down portion sizes of high calorie, frequently consumed foods; avoiding appetizers; eliminating a second cocktail; replacing a second serving of steak at dinner with vegetables; or ordering roasted, baked, grilled, or steamed foods instead of fried, deep fried, sautéed, or creamed items when dining out.

Patients should also be advised to increase their intake of foods that are low in totally calories while also increasing the fiber content of their foods and replacing high-fat food with minimally processed, carbohydrates or proteins. A diet rich in food that is low in energy density, such as fruits, vegetables, and soups, will reduce caloric intake while also promoting satiety. This strategy is thought to be superior to a fat and portion restricted diet. A 2010 study evaluated the energy density of daily intake for three different groups. One group comprised overweight adults, another was of normal weight adults and the third consisted of weight loss maintainers (who had lost 10% of maximum body weight and kept it off for 5 years). Dietary intake was collected via three 24-hour phone dietary recalls and energy density was calculated using three different methods. Results showed that those in the weight loss maintainer group consumed significantly less energy per day (49). When the energy density of food is decreased, but the volume of food remains the same, calories consumed will decrease. In one study, the energy density of foods was lowered by 30%, consequently, daily energy intake also decreased by 30% (77).

Providing calorie recommendations, and instructions to keep food and physical activity records, will help patients see what factors influence their weight. Patients who record their daily food intake (i.e., food item, portion, calories, time of eating, and fat grams, if desired) as well as their physical activity for the day, are more successful in weight loss and weight maintenance efforts than those who do not (78). Some patients find it helpful to write down their emotions during their meal times to help assess whether the patient is eating out of emotion or out of hunger. The National Weight Control Registry data indicates that frequent self-monitoring of caloric intake and weight helps patients to maintain their new lower weight (79).

Patients who are able to self-monitor are more successful in weight loss efforts than those who do not self-monitor. Self-monitoring fosters awareness, an essential initial step in behavioral change. The Handbook of Assessment Methods for Eating Behaviors and Weight-Related Problems states that, “It is well established that self-monitoring or recording daily intakes via food records is a useful tool in weight loss programs” (80). Furthermore, the interplay among awareness, self-observation, recording, and self-evaluation can enhance self-management by improving how individuals attend to their health. A common denominator among all successful weight losers is self-monitoring (57;78;79;81). Patients who use food records report they have a heighted awareness of their eating behaviors, they recognize the need to make significant dietary changes and they are more able to “stay on track.” In addition, their label reading, fat and calorie counting, and portion determination skills are improved (81). These are all important skills that overweight or obese individuals need to lose weight and/or maintain their weight at lower levels. These are also skills for making healthier lifestyle choices throughout the rest of their lives, thus improving their overall health.

7.2 Self-reports of Energy Intake are Almost Always Underestimated

The average, healthy, adult, American male consumes approximately 2,800 calories per day, and the average female about 1,800 calories. Yet, such intakes are seldom accurately reported in a diet recall or food log. Usually, the recall or food log will show a much lower calorie intake. Reporting energy intakes is difficult, even for individuals who have been trained to do so accurately. In other words, people are widely unaware of what or how much they are eating on a daily basis. Even small omissions or inaccurate portion size reports could subtract hundreds of calories from the total calorie consumption of the day. Several days of observation are necessary to achieve accurate calorie intake since energy balance is achieved over weeks, not days. Thus, a report from any given day is certain to have a considerable amount of random as well as probably systematic error when used to estimate usual calorie intake.

Underreporting of energy intakes is common and usually off by a large margin (20%) in virtually every patient, and particularly so among the overweight population (82). Objective biomarkers of energy output such as doubly labeled water indicate that underreporting could be as great as 1,200 calories per day in very obese persons (83;84). Subjective reports of energy intake are often so low that if they were actually true, those patients should be losing weight. But in fact, they are gaining weight. It is biologically impossible to gain weight on a hypo-caloric diet, so underreporting must be considered (85).

The most common problem arising from these errors is that patients’ actual weight loss is usually less than was desired. This could be a result of underreporting and underestimating intake. Typically, when overweight people report their intakes by recall, they often underestimate their intakes by 30 to 40%. These patients are likely to make similar mistakes in underestimating their intakes on reducing diets because of difficulties in portion size judgment, forgetting, the social desirability of reporting adherence to the prescribed regimen, and other factors. This can be explained by the “flat-slope phenomenon,” which describes how individuals with a high intake of food tend to underreport their intake while those with a low intake of food tend to over report (48). For example, many people underestimate or forget that their very large food intake on weekends “counts”; or they forget to count alcohol, snacks, or something they may have had a second helping of. Thus, on a 1,200-calorie diet, actual consumption may be 2,600 calories or more on some days, and weight loss understandably slows.

Methods for assisting dieters in minimizing diet recall errors would be to use household measures or weighing scales to determine the portion size consumed more accurately, in addition to the use of food diaries. Portion-controlled liquid meal replacements, frozen low calorie entrees, and other foods that are fixed in portion sizes might also be helpful in not only portion control but also in reporting that intake because the portion size is usually labeled (see 10.3 Formulas and Meal Replacements).

Consistency in reporting intake does not necessarily mean that the reported intake is accurate, which is especially true for those who are morbidly obese. Underreporting is also especially pronounced among women, smokers, and those of low educational and socioeconomic status (83). In addition, those who underreport tend to be consistent under-reporters, and so they are difficult to detect since the records are all similar (83). In spite of these limitations, patients who keep food journals or diaries, are more successful in losing and/or maintaining weight loss than those who do not (78). Additionally, self-reports are useful for the patient and counselor alike to obtaining clues on dietary patterns that may be helpful in working through barriers to weight loss.

7.3 Remind Patients to Stay Active: Self-reports of Energy Output Tend to be Overestimated

Self-reports of energy output as measured by physical activity questionnaires have been validated using doubly labeled water methods. Some lengthy questionnaires used for research purposes are quite accurate at estimating physical activity (86). However, the shorter questionnaires, used clinically, are not accurate for individuals (87). As is the case with dietary recalls, physical activity questionnaires may be useful for self-monitoring, but should not be used for prescribing or assessing energy intakes or outputs exactly. Motion sensors (pedometers or accelerometers) have become popular in recent years. Accelerometers and pedometers provide objective physical activity measurements and are sensitive to walking (88). Either is a worthwhile purchase to help in self-monitoring of physical activity.

Accelerometers measure the body’s acceleration in one direction for long periods. In contrast to the pedometer, an accelerometer distinguishes between different walking speeds and intensities. Many accelerometers also record the amount of steps taken, allowing comparison with pedometers. Accelerometers have been validated as accurate forms of measurement in regards to steps counted (88). On the other hand, pedometers are less expensive because they measure only step count and not walking speed so this may be a better option for someone who is not willing or able to purchase an accelerometer. Unfortunately, pedometers are less sensitive to detecting steps if a person is walking slowly (e.g., less than two miles per hour). When walking at this slow of a pace, pedometers underestimate step count by approximately 50 to 90%. However, if a person is walking above 3.5 miles per hour, most pedometers approach 100% accuracy in step count (89). If a patient chooses to purchases a pedometer, piezoelectric pedometers are best because they are more accurate than spring-levered pedometers. This is especially true for obese or elderly individuals, who are more likely to walk at a slower pace, because these pedometers measure slow walking speeds more accurately (89;90).

If a motion sensor, either a pedometer or accelerometer, has a calorie counter built in, it could be inaccurate. Rather than focusing on the calories burned according to the motion sensor, patients should focus on the number of steps walked per day. Goals of a certain number of steps each day can be prescribed and patients are able to monitor their progress on their own. One common step count goal is 10,000 steps per day. However, most patients need to work up to that number so they should set smaller, more achievable goals until they feel they can reach the ultimate goal of 10,000 steps. The basic point is that if the patient can be induced to walk 10,000 steps a day or to gradually increase the number of steps he walks no matter how low it is, progress is being made, and the finer points of absolute accuracy can be disregarded. The ability for patients to quantify physical activity in a tangible way fosters commitment, encourages performance, provides a realistic goal, and eventually may provide a feeling of self-accomplishment.

7.4 Remind Patients that Shifts in Water Balance May Obscure True Decreases in Body Fat and Overestimate Fat-related Weight Loss

Dramatic decreases in weight often occur on reducing diets, particularly in the first few weeks. This is especially true for those on severely hypo-caloric regimes (with deficits of 1,000 calories per day), those on ketogenic diets, and those on very low carbohydrate diets (95;96). The type of fluid shift (loss or increase of fluid) depends on the caloric level and macronutrient composition of each diet. For example, high protein, low carbohydrate diets increase obligatory urine volume due to greater urinary loads of nitrogen, ketones, and other solutes (particularly sodium, if they are low in sodium), and will result in increased fluid losses . Increased loss of lean tissue is also associated with large fluid losses because of loss of nitrogen from tissues, such as muscle, along with water, which comprises most of the lean tissue. Fluid losses are also more apparent on hypocaloric regimes that are very low in carbohydrate (<100 grams/day and especially <50 grams of carbohydrate), since they are insufficient to replete glycogen stores, and glycogen consists largely of carbohydrate and water. Shifts in water balance may cause very dramatic deviations from the usual linear slope of weight loss. They may also cause rapid weight accumulation over just a few days if there is a period of non-adherence. This is a result of the body storing glycogen and water when the dieter eats a large carbohydrate load after a period of carbohydrate deprivation. Fluid accumulates rapidly because for every gram of glycogen that gets stored, three grams of water are stored with it. Thus, gains or losses of glycogen are associated with large changes in body water balance and water weight. These shifts can be sudden and alarming to patients (96).

8.1 Calculated-Deficit Diets

From the clinical standpoint, hypocaloric diets must be defined in terms of the energy needs of the individual and the deficit that will be created, since it is the size of the energy deficit that will determine the physiological effects expected. Ideally, energy needs should be based on resting metabolic rate (RMR), while taking into account level of physical activity. If possible, RMR should be measured (e.g., with indirect calorimetry) (70), since it can vary significantly from prediction calculations in obese individuals (97). Products such as the MedGem^TM indirect calorimeter can be used in an office environment to quickly, easily, and accurately estimate a patient’s RMR (98), although caution should be used, since it may over-estimate RMR in overweight individuals [Anderson et al., 2014]. However, “if RMR cannot be measured, then the Mifflin-St. Jeor equation using actual weight is the most accurate for estimating RMR for overweight and obese individuals” (57;70). According to the Academy of Nutrition and Dietetics Evidence Analysis Library (EAL), the Mifflin-St. Jeor equation accurately predicted RMR using actual body weight within +/- 10% of measured RMR in 70% of obese individuals (57). Of the remaining 30%, 9% were overestimations and 21% were underestimations. Table 12 presents this equation. The individual error range was a maximum overestimate of 15% to a maximum underestimate of 20%” (24). While the Harris-Benedict and WHO equations are often used in clinical practice with reasonable accuracy, results have been mixed regarding their applications to individuals who are overweight or obese.

After calculating the patient’s RMR, his/her RMR should be multiplied by an appropriate physical activity factor to provide a baseline daily caloric level for weight maintenance. Once a baseline caloric level is configured, the patient’s recommended calorie intake should be reduced to facilitate weight loss. Reducing the calorie level by 500 calories is a common strategy to yield a weight loss of approximately one pound per week, although reductions of up to 750 calories per day are sometimes used (31). Another approach is to reduce current caloric intake by 30% (31). However, depending on the patient’s BMI and current intake, a larger reduction in calories may be needed, as described in the following sections. Calculations for estimating energy needs and various physical activity factors are provided in Table 12.

The major determinant of weight loss on reducing diets is size of the actual, and not the prescribed, caloric deficit. Thus, if energy needs can be measured or estimated with reasonable accuracy, then a calculated caloric deficit would be the preferred method (70). Once caloric needs for current weight maintenance are determined, the deficit can be calculated by subtracting 500-750 calories, or with a 30% caloric reduction. Diets that reduce caloric intake relative to energy expenditure result in weight loss, regardless of macronutrient composition (31).

Recent advances in methodology such as mathematical modeling have demonstrated the amount of weight loss may not be as high as one might predict based on energy balance alone (99). This is due largely to metabolic slowing that occurs with weight loss, even after accounting for declines in lean tissue (100). As weight is lost, total energy expenditure declines; so fewer calories are needed to maintain weight (101). Thus, ideally, RMR should be measured periodically as weight is lost, and caloric intake recommendations adjusted accordingly. Physical activity may ameliorate some of this decline, but not all (100).

8.2 Low-Calorie Diets (LCDs): 1,000 to 1,200 Calories for Females, 1,200 to 1,600 Calories for Males

The caloric level of the diet requires attention first and foremost; after this, other characteristics of the diet can be considered. Diets that reduce caloric intake to about 1,200 to 1,500 calories in women, and 1,500 to 1,800 calories in men will result in weight loss if they are adhered to perfectly, regardless of their macronutrient composition (102; 31). This is because such caloric levels will result in a caloric deficit for most overweight and obese adults. The National Institutes of Health have recommended low calorie diets of 1,000 to 1200 calories for women, and 1,200 to 1,600 calories per day for men, although adherence may be difficult with lower caloric intake (24;65). Either way, the rationale is that on such regimens, a deficit of approximately 500 to 1,000 calories per day will be created, which should result in a slow progressive weight loss of one to two pounds per week. Two sample menus and other materials at 1,200 and 1,600 calories and many aids to assist the physician are provided in the NIH monograph (65). The ChooseMyPlate.gov website also provides such materials and worksheets that can be accessed by consumers, and guide them daily through their weight loss.

It is important to recognize that when using fixed calorie reducing diet plans, that even with perfect adherence, individuals will vary greatly in their weight loss. This is because their resting energy needs and physical activity, and thus energy outputs, often differ markedly, and may fluctuate even within an individual.

The National Institute of Health’s Obesity Initiative sponsored an evidence based review of low calorie diets (65). It found that on average, diets such as these reduced body weight by an average of 8% over three to 12 months of treatment, and that the losses were accompanied by decreases in abdominal fat, which is the type of adipose tissue deposition that is associated with highest chronic disease risk. However, no improvements were noted in cardio-respiratory fitness as measured by VO2 max unless the dieters also increased their physical activity (24).

There are many pre-packaged meals on the market that fit into the low-calorie diet category, including Healthy Choice®, Lean Cuisine®, and Smart Ones®. Some patients find them useful for one or more meals a day since they provide a measured and moderate amount of calories per meal. Weight Watchers®^TM, Jenny Craig®^TM, and NutriSystem^TM are more structured commercial programs that also can provide pre-packed, pre-portioned food options. See Tables 21 and 23 for a list of these programs and products.

8.3 Very-Low-Calorie Diets (VLCDs): ≤ 800 Calories

VLCDs supply 800 calories or less, a total of 50 to 80 grams of protein, 100% of the Reference Daily Intake (RDI) for vitamins and minerals per day, and are designed to produce very rapid weight loss while still preserving lean body mass (39). VLCDs are prescribed as a form of intensive diet therapy, which require close medical supervision, and should not be used long-term. They are intended to induce quick and significant weight loss of about 3-5 pounds weekly, or 14 to 21 kilograms over a short time (11-14 weeks). VLCD’s are sometimes used to provide a jump-start to further obesity treatment. This is typically done through meal-replacement liquid diets (6), as described below. Any diet, regardless of its caloric level, that provides less than half of an individual’s energy needs can be considered a VLCD for that individual. However, virtually all adults have energy needs that exceed 1,000 calories per day, and therefore any diet below 500 calories, and for most individuals, diets below 800 calories, are VLCDs. Depending on a person’s caloric requirements, other regimens that are higher in calories may also be VLCD for some people with very high energy needs using this same rule of thumb; for example, a 1,200 calorie diet prescribed to a man whose usual intake is 3,000 calories would also qualify as a VLCD..

8.4 Fasting and Alternate Day Fasting

Total fasting is contraindicated for weight reduction because it causes excessive breakdown of lean tissue and ketosis. Also, the compensatory decreases in resting metabolism and physical activity on total fasts are profound and counterproductive, since they lower energy output (24;5).

Short-term modified alternate-day fasting (ADF) is a relatively new dietary strategy that has not yet received enough research attention to support the effectiveness of its use. On typical ADF diets, patients consume 25% of their energy needs on the fast day, and food intake ad libitum the next day. Many of the ADF studies do not include control groups that undertake other dietary approaches to weight loss, plus the sample sizes have been small (15-64 subjects) and the durations short (8-12 weeks) (110; 111; 112; 113; 114). However, results to date show similar weight loss and improvements in metabolic factors as compared to studies using other dietary approaches to weight loss, as well as good adherence. For example, Varady et al found that ADF was a viable diet option, helping obese patients not only to lose weight, but to also decrease their risk of coronary artery disease (CAD) (110). Emerging evidence suggests that the relative contribution of fat and carbohydrate in ADF diets does not have an impact on weight and blood lipid profiles (115). An alternative fasting regimen that has become popular among some dieters is two days of fast followed by five days of usual eat. Further research is needed with larger samples, dietary control groups, and longer durations before ADF’s widespread use for weight loss purposes, however.

An alternative intermittent fasting regimen that has become popular among some dieters is two non-consecutive days of fasting and five unrestrictive days of usual eating each week. This “5:2 Diet”, developed by Dr. Michael Mosley in the United Kingdom, has spread widely throughout Europe, and now the United States. For the two fast days, men are to eat no more than 600 kcals, and women 500 kcals. Usually this consists of a very light breakfast and dinner with little or no lunch. Anecdotally, weight loss has been similar to other dietary approaches to weight loss (~2 pounds/week) for short terms (~6 weeks). However, research is lacking on this specific type of diet, so its long-term safety and efficacy has not been tested, and its appropriateness in varying populations is currently unknown

9.1 Macronutrient Distribution

As described above, the macronutrient composition of the diet does not appear to play a major role in overall weight loss; reduced-calorie diets result in clinically meaningful weight loss regardless of which macronutrients they emphasize (121; 118). There is one exception: over the short term, low carbohydrate diets are ketogenic, and may cause a greater loss of body water than body fat (at least in the first few days of the diet). Water weight is regained when the diet ceases, or when carbohydrate intake increases. In this case, glycogen stores, which hold water, are regained. Generally, when any reducing diet is maintained over the long term, if it remains hypocaloric, it will result in a loss of body fat – regardless of the distribution of macronutrients.

Although weight loss is caused by many reduced-calorie diets, the nutritional adequacy of different calorie levels and macronutrient composition for weight loss diets varies (122). The lower the reducing diet is in calories, and the more its composition differs from usual levels, the greater the risk of nutrient inadequacy. For the most part, moderate fat, balanced macronutrient reduction diets are nutritionally adequate. Very low-fat diets tend to be deficient in vitamins E, B12, calcium, iron and zinc. High fat, low carbohydrate diets are nutritionally inadequate, and require supplementation to make them nutritionally adequate in many nutrients (96;123;124). They are often low in fiber, so constipation may occur. In this case, fiber supplements and ample water intake may be recommended. Dietary supplements used on weight reduction diets should be within RDA levels and below upper safe limits.

Metabolic parameters may improve on some various popular diets including decreased blood pressure, blood lipids, blood sugar, and serum insulin, related to energy restriction and weight loss, regardless of the macronutrient composition of the diet. However, there are some differences. Moderate fat, balanced nutrient reduction diets lower low-density lipoprotein (LDL) cholesterol, normalize plasma triglycerides, and normalize ratios of HDL/total cholesterol. High fat, very low carbohydrate diets result in ketosis. Low and very low-fat diets (e.g., 15-20% of calories) reduce low-density lipoprotein (LDL) cholesterol, and after a transient rise in triglycerides, may also decrease plasma triglyceride levels. Low carbohydrate diets (e.g., <100 grams of carbohydrate) that result in weight loss may also cause a decrease in blood lipids, blood glucose and insulin levels, and blood pressure. However, these diets are often high in saturated fat, total fat, and in dietary cholesterol, and low in plant-based nutrients such as fiber, so variability in metabolic responses may be seen, due in part to genetic predisposition. Moreover, these diets are ketogenic, often causing signs and symptoms such as diuresis, dizziness, halitosis, fatigue, weakness, hypotension, and malaise.

Hunger may vary on the different diets, and also from one individual to the next, but little objective evidence is available for comparing different reducing diets on their anti-hunger effects. Many factors affect hunger, appetite and subsequent food intake, including interactions between physiological and non-physiological factors. Schoeller and Buchholz speculate that a greater consumption of protein may increase satiety, which in turn results in better adherence to hypocaloric diets, however, substantial long-term evidence to support this supposition is lacking (124), and more research is needed in this area.

Long-term dietary adherence is likely to be a function primarily of psychological and lifestyle issues rather than macronutrient composition itself. At present little is known about the nutritional or other characteristics of diets that maximize adherence. It is likely that "one size does not fit all" in this respect, so the importance of individualization is underscored.

9.2 Protein

This section outlines dietary protein needs during weight reduction. The Recommended Dietary Allowance for protein is 0.8 grams per kilogram per day, but most Americans eat about 1.2 grams per kilogram per day, or approximately 15% of their total caloric intakes from protein. For people in energy balance and at a stable weight, the World Health Organization (WHO) recommends that dietary protein should account for approximately 10 to 15% of energy intake (125).

9.3 Fat

This section outlines dietary fat needs during weight reduction.

9.4 Carbohydrates and the Glycemic Index

The following section reviews carbohydrate needs during weight reduction, and the glycemic index.

9.5 Water

This section discusses water and electrolyte needs during weight reduction.

9.6 Electrolytes

Under normal circumstances on a well-balanced diet that is not overly restrictive with energy, electrolyte balance is maintained. If an individual may be losing excess electrolytes due to high sweat or urine losses, electrolytes can usually be replaced with normal foods (67). The American diet is overly abundant in sodium. Potassium is not so abundant but can be obtained in fruits and vegetables. Examples of foods that are high in both sodium and potassium include tomato sauces and vegetable soups.

Electrolyte levels are of particular concern on VLCD, since occasionally cardiac arrhythmias have resulted from hypokalemia on such regimens (105). Since hypokalemia can be fatal, electrolyte levels must always be monitored on VLCD.

9.7 Vitamins and Minerals

The next section outlines vitamin and mineral needs during weight reduction.

9.8 Fiber

The next section outlines dietary fiber needs during weight reduction.

9.9 Energy-Dense Beverages, Alcohol, and Energy-Free Artificially and Naturally Sweetened Beverages

Currently, it is estimated that the mean intake of ”added” sugars in the American diet is about 15.8% of total energy, and that the largest source of these added sugars is from calorically sweetened beverages such as soft drinks, fruit aides, and other sweetened beverages, accounting for 47% of total added sugars in the diet (184;185) . The term “energy-dense beverage” encompasses a wide variety of beverages, including sugar sweetened soda, fruit drinks, juice, lemonade, sweetened iced tea, milk and soy beverages, and alcohol. Alcohol is especially calorie dense (7 Cal/gm, vs 4 for sugars), and it also may bypass satiety mechanisms and lead to a lack of ability to control eating. Curiously, in recent years it has been neglected in spite of the fact that many adults (and unfortunately some younger people) drink alcohol on a regular basis.

9.10 Energy Density

Energy density, or caloric density, is defined as the calories provided per unit weight of food eaten (such as calories/gram). When the composition of a diet of usual foods is decreased in fat, the energy density of the diet tends to fall since the total weight of food consumed remains constant, or may increase (196-198) . Some of the beneficial effects of low fat diets in weight loss and maintenance may be due, at least in part, to low energy-density, which may promote satiety. The premise is that if foods bring more weight than calories into the body, gastric distention and intestinal bulking may promote fullness. For example, foods high in water and/or fiber tend to have low energy density, with some that are very high in volume, such as unbuttered popcorn. Their inclusion in a weight reduction diet is advocated by some experts for this reason (10), and because they might increase overall dietary quality (199). As will be discussed later, some evidence suggests that low-energy density, high-volume diets may help people ingest fewer calories and thus may assist with weight loss, although longer-term research is needed (200; 201;199).

9.11 Volume of Food

Low energy density is the basis of the “Volumetrics” diet put forth by Dr. Barbara Rolls. This diet is high in fruits, vegetables, cooked whole grains and fibrous foods, which are high in water and bulk, to add volume for satiety without extra calories (285). In a one year study completed by 71 obese women, the low energy density diet group showed slightly better weight loss than a low fat diet group, and reported lower hunger (324). Cross-sectional work has shown that people who maintain large

amounts of weight loss over years tend to eat a lower energy density diet than normal weight or obese subjects (201). Some other diets tend to be low in energy density without specifically targeting energy density, through their inclusion of fruits, vegetables, and fibrous foods (199).

10.1 Registered Dietitians: Dietetic Advice and Individualized Eating Plans

A registered dietitian is a food and nutrition expert who has met academic and professional requirements including:

• A bachelor’s degree at an accredited university, approved by the Commission on Accreditation for Dietetics Education (CADE) of the American Dietetic Association (ADA).
• Completed an accredited, supervised, experiential practice program (dietetic internship) at a health-care facility, community agency, and/or foodservice corporation, including at least 900 hours of hands-on experience.
• Pass a national examination administered by the Commission on Dietetic Registration (CDR).
• Complete continuing professional education requirements to maintain registration.

Many physicians lack the time that obese patients require for successful weight control therapy. Referral for dietary counseling to a registered dietitian (RD) is useful for many patients, particularly those who have comorbidities that also require medical nutrition therapy. Many registered dietitians also hold certifications in specialized areas of practice, including weight management, providing additional expertise in the management and treatment of obesity (203). They are able to understand more complicated therapeutic dietary recommendations that many patients, especially those with comorbidities, require. Practicing registered dietitians in your area can be located using the website for the Academy of Nutrition and Dietetics at http://www.eatright.org/.

10.2 Commercial Weight Loss Programs

Commercial non-medical weight control programs are popular and widely available in the United States and Canada. They will be discussed in detail in the following section.

10.3 Formulas and Meal Replacements

In addition to commercial weight loss programs, many meal replacement and formula products for weight control are now available. Patients can purchase these products on their own in supermarkets, drug stores, and online. Unlike very low-calorie diet formulas, which are medical foods that are usually provided as part of a medically supervised treatment program (see Table 13), these products can be purchased by anyone.

10.4 Weight Loss Books and Manuals

In addition to weight loss products, Table 24 provides some examples of popular diet books. Books are difficult to use on one’s own because there is little reinforcement. The quality of self-help books on weight control ranges from the sublime to the ridiculous. Among the better, older books currently on the market are the LEARN® Program for Weight Management, which is a sound 15 week course that is usually administered within a treatment program (208). The book is effective when it is part of the treatment program. However, the charges for such a program are considerable, the program is not available in all parts of the country, the effectiveness of self-directed efforts using the book by itself has not been evaluated, and the dietary advice is often vague. Another good book is Volumetrics by Barbara Rolls PhD (209), which encourages a diet based on foods that have a low energy density, meaning that they contain few calories per gram of weight. Dr. Rolls’ research has shown that foods with large volume but few calories can provide satiety while helping individuals avoid over-consumption of energy. Such foods are usually high in water and fiber, while low in fat. Although the long-term efficacy of this specific diet has yet to be affirmed, the diet is rich in fruits, vegetables, and other healthful foods (209). The bottom line on diet books is that with few exceptions, the dieter is sure to lose his or her money , but whether weight is lost or not is less certain. Moreover, in spite of the hype there is little evidence that, aside from the few books mentioned above, that the diets “work” and that the authors have discovered a unique new scientific principle that causes weight loss.

10.5 Web-Based Treatment Programs and Resources

The Internet provides some excellent resources for those who want and need more information. However, it also includes sites with questionable recommendations, so individuals should proceed with caution. Web-based resources are discussed below.

10.7 Voluntary Self-Help Programs

Self-help programs led by laypersons are voluntary programs that charge very low or no fees. National organizations include TOPS Club, Inc.® (Take Off Pounds Sensibly), OA (Overeaters Anonymous®), and others. These programs are designed primarily to provide group support to those who have weight problems, rather than to provide and supervise weight reduction diets.

10.8 Mobile Applications for Weight Loss

As people’s lives become more mobile, so do the tools that help them lose weight. Calorie tracking programs are available to monitor daily intake, and fitness programs provide sample workouts and activity logs. Other apps are available to promote water consumption and provide tips and support. As with web-based resources, these should be used in conjunction with physician or dietician-led interventions, and not as a replacement for them. Though research on the efficacy of these programs is still scant, one recent study suggests that combining some form of counseling alongside a smart-phone based platform led to greater results than either counseling or smart-phone use alone (237). Examples of current available apps and the platforms on which they are available are summarized in Table 26.

12.1 Nutrient Needs

Although energy needs are less during weight maintenance, the requirements for protein, essential fatty acids, carbohydrate, dietary fiber, vitamins and minerals are similar to those of any normal adult. The 2010 Dietary Guidelines for Americans recommend that all Americans, including those who are watching their weight, to adopt the habits listed (see Table 1).

There is currently much debate about the ideal macronutrient distribution in diets for weight maintenance, but at present very few long-term studies are available on the effects of macronutrient content on weight maintenance. A low-fat, reduced-energy is the best studied diet and the most prescribed for weight maintenance (AND).