A new study from the US found that normal weight women in their 40s and older who drank a light to moderate amount of alcohol gained less
weight and had a lower risk of becoming obese and overweight compared to their non-drinking counterparts.
The researchers, from the Brigham and Women's Hospital, and the Harvard School of Public Health in Boston, Massachusetts, have written about their study in a paper published online in the 8 March issue of Archives of Internal Medicine.
At 7 calories per gram (equivalent to 199 calories per ounce), alcohol is potentially a significant source of dietary calories, and more than half of adult Americans are alcohol drinkers. Meanwhile obesity is approaching epidemic proportions in the US, yet evidence on the extent to which alcohol consumption contributes to this public health crisis is patchy, suggested the authors.
For their prospective cohort study, which was sponsored by grants from the National Institutes of Health, lead author Dr Lu Wang, of Brigham and Women's Hospital, and colleagues examined data from 19,220 women living in the US who were aged 39 and over, had no traces of cardiovascular disease, cancer, or diabetes, and whose body mass index (BMI) was in the range classified as normal (18.5 to less than 25). BMI is calculated as weight in kilograms divided by height in meters squared.
At the start of the study the women filled in a questionnaire that asked them about their daily alcohol consumption. After that they filled in questionnaires about their weight every year for an average of 13 years.
The results showed that:
- At the start of the study, 38.2 per cent reported drinking no alcohol, 32.8 per cent reported drinking less than 5 grams a day, 20.1 per cent reported drinking 5 to less than 15 grams, 5.9 per cent reported drinking 15 to less than 30 grams, and 3 per cent reported drinking 30 or more grams of alcohol a day.
- Over the 13 years of follow up, the women's average weight went up steadily.
- 41.3 per cent of the women became overweight (BMI of 25 or more), and 3.8 per cent became obese (BMI of 30 or more).
- After adjusting for potential confounders like baseline BMI, smoking, other calorie sources, exercise, and other lifestyle and dietary factors, there was an inverse association between the amount of daily alcohol the women said they drank in their initial questionnaires and the weight gained over the follow up.
- Compared with women who did not drink at all, those who consumed some but less than 40 grams of alcohol a day had a lower risk of becoming overweight or obese.
- Women who drank 15 to less than 30 grams of alcohol per day had the lowest risk, which was nearly 30 percent lower than that of their non-drinking counterparts.
They concluded that:
"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."
However, the authors stressed that given the potential medical and psychosocial problems of alcohol consumption, recommendations about its use should be made on an individual by individual basis.
They also suggested more studies are needed to find out the biological mechanisms of the role played by alcohol in energy metabolism, and whether any physiological and genetic factors are involved.
"Alcohol Consumption, Weight Gain, and Risk of Becoming Overweight in Middle-aged and Older Women."
Lu Wang; I-Min Lee; JoAnn E. Manson; Julie E. Buring; Howard D. Sesso.
Arch Intern Med., Vol. 170 No. 5, pp 453-461, March 8, 2010.
Source: JAMA and Archives Journals.
Written by: Catharine Paddock, PhD