Two recent reports give conflicting results concerning the link between moderate drinking and obesity. The first study by Arif et al looked at the association between obesity and alcohol consumption in 8,236 non-smoking. US respondents participating in the Third National Health and Nutrition Examination Survey. Alcohol consumption was measured through history of drinking, binge drinking, quantity of drinks/day, frequency of drinking, and average volume of drinks/week.
Approximately 46% of respondents were classified as current drinkers. Current drinkers had lower odds of obesity (adjusted odds ratio=0.73, 95% CI: 0.55, 0.97) as compared to non-drinkers. The odds of overweight and obesity were significantly greater among binge drinkers and those consuming four or more drinks/day, however.
The study is important as it evaluates the pattern of drinking, and because it excluded ever smokers; smoking is one of the main confounders in studies of alcohol and body weight, as drinkers are more likely to smoke and smokers tend to be leaner. The results suggest that moderate, frequent, drinking is associated with the lowest body mass index, a measure of obesity. The paper also reports that heavy or binge drinking negates any potentially protective effects on obesity.
The second paper by Wannamethee SG et al looked at the effects of quantity and type of drink and time relation with meals. The authors examined the cross-sectional association between alcohol intake, patterns of drinking and adiposity [body mass index (BMI), waist-to-hip ratio (WHR), waist circumference (WC) and percentage body fat (%BF)]. They studied 3,327 men aged 6079 with no history of myocardial infarction, stroke or diabetes drawn from general practices in 24 British towns.
Results indicated that BMI, WHR, WC and %BF increased significantly with increasing alcohol intake even after adjustment for potential confounders. Men who consumed >21 units/week showed higher levels of obesity than nondrinkers and lighter drinkers, irrespective of the predominant type of drink consumed (wine, beer, spirits or mixed). Among drinkers, a positive association was seen between alcohol intake and the adiposity variables irrespective of whether the alcohol was drunk with or separately from meals.
The authors conclude that higher alcohol consumption (>21 units/week) is positively associated with higher obesity , findings that are not supported in many recent studies of light to-moderate drinkers. The results show no increase, for very light consumers (1-6 drinks/week), but the next higher group (7-20 drinks/week) shows an increase in most measures.
The reasons why the subjects in this study did not show an inverse association with body weight with light drinking, is unclear. Only men were assessed in this study and it is known that binge drinking negates any potential reduction in obesity. Drinking pattern or frequency of drinking were not measured in this study, which may account for the findings.
Sources:Arif AA, Rohrer JE. Patterns of alcohol drinking and its association with obesity: data from the Third National Health and Nutrition Examination Survey, 1988-1994. BMC Public Health 2005;5:126
Wannamethee SG et al Alcohol and adiposity: effects of quantity and type of drink and time relation with meals. Int J Obes 2005;29:14361444.