Effect of a low-carbohydrate diet on appetite, blood glucose levels, and insulin resistance in obese patients with type 2 diabetes

Ann Intern Med. 2005 Mar 15;142(6):403-11. doi: 10.7326/0003-4819-142-6-200503150-00006.

Abstract

Background: It is not known how a low-carbohydrate, high-protein, high-fat diet causes weight loss or how it affects blood glucose levels in patients with type 2 diabetes.

Objective: To determine effects of a strict low-carbohydrate diet on body weight, body water, energy intake and expenditure, glycemic control, insulin sensitivity, and lipid levels in obese patients with type 2 diabetes.

Design: Inpatient comparison of 2 diets.

Setting: General clinical research center of a university hospital.

Patients: 10 obese patients with type 2 diabetes.

Intervention: Usual diets for 7 days followed by a low-carbohydrate diet for 14 days.

Measurements: Body weight, water, and composition; energy intake and expenditure; diet satisfaction; hemoglobin A1c; insulin sensitivity; 24-hour urinary ketone excretion; and plasma profiles of glucose, insulin, leptin, and ghrelin.

Results: On the low-carbohydrate diet, mean energy intake decreased from 3111 kcal/d to 2164 kcal/d. The mean energy deficit of 1027 kcal/d (median, 737 kcal/d) completely accounted for the weight loss of 1.65 kg in 14 days (median, 1.34 kg in 14 days). Mean 24-hour plasma profiles of glucose levels normalized, mean hemoglobin A1c decreased from 7.3% to 6.8%, and insulin sensitivity improved by approximately 75%. Mean plasma triglyceride and cholesterol levels decreased (change, -35% and -10%, respectively).

Limitations: The study was limited by the short duration, small number of participants, and lack of a strict control group.

Conclusion: In a small group of obese patients with type 2 diabetes, a low-carbohydrate diet followed for 2 weeks resulted in spontaneous reduction in energy intake to a level appropriate to their height; weight loss that was completely accounted for by reduced caloric intake; much improved 24-hour blood glucose profiles, insulin sensitivity, and hemoglobin A1c; and decreased plasma triglyceride and cholesterol levels. The long-term effects of this diet, however, remain uncertain.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Appetite*
  • Blood Glucose / metabolism*
  • Body Water / physiology
  • Diabetes Mellitus, Type 2 / blood
  • Diabetes Mellitus, Type 2 / complications*
  • Diabetes Mellitus, Type 2 / metabolism
  • Diet, Reducing*
  • Dietary Carbohydrates / administration & dosage*
  • Energy Intake
  • Energy Metabolism / physiology
  • Female
  • Hormones / blood
  • Humans
  • Insulin / blood
  • Insulin Resistance / physiology*
  • Ketone Bodies / metabolism
  • Kidney Function Tests
  • Lipids / blood
  • Male
  • Middle Aged
  • Obesity / complications
  • Obesity / diet therapy*
  • Obesity / metabolism
  • Weight Loss

Substances

  • Blood Glucose
  • Dietary Carbohydrates
  • Hormones
  • Insulin
  • Ketone Bodies
  • Lipids