BACKGROUND:

The obesity epidemic is a major health problem in the United States. Alcohol consumption is a source of energy intake that may contribute to body weight gain and development of obesity. However, previous studies of this relationship have been limited, with inconsistent results.

METHODS:

We conducted a prospective cohort study among 19 220 US women aged 38.9 years or older who were free of cardiovascular disease, cancer, and diabetes mellitus and had a baseline body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) within the normal range of 18.5 to less than 25. Alcoholic beverage consumption was reported on a baseline questionnaire. Body weight was self-reported on baseline and 8 annual follow-up questionnaires.

RESULTS:

There was an inverse association between amount of alcohol consumed at baseline and weight gained during 12.9 years of follow-up. A total of 7942 (41.3%) initially normal-weight women became overweight or obese (BMI > or =25) and 732 (3.8%) became obese (BMI > or =30). After adjusting for age, baseline BMI, smoking status, nonalcohol energy intake, physical activity level, and other lifestyle and dietary factors, the relative risks of becoming overweight or obese across total alcohol intake of 0, more than 0 to less than 5, 5 to less than 15, 15 to less than 30, and 30 g/d or more were 1.00, 0.96, 0.86, 0.70, and 0.73, respectively (P( )for trend( )<.001). The corresponding relative risks of becoming obese were 1.00, 0.75, 0.43, 0.39, and 0.29 (P( )for trend( )<.001). The associations were similar by subgroups of age, smoking status, physical activity level, and baseline BMI.

CONCLUSION:

Compared with nondrinkers, initially normal-weight women who consumed a light to moderate amount of alcohol gained less weight and had a lower risk of becoming overweight and/or obese during 12.9 years of follow-up.