The public, and scientists, have long been concerned about the relation between alcohol consumption and weight gain, as all alcoholic beverages contain calories. However, most epidemiologic studies do not find that light or moderate drinkers weigh more than their abstaining peers, and some even show lower weight among moderate drinkers than among abstainers. The reasons for this apparent effect are unclear.
The present study is important as it describes the effects on weight of changes in alcohol intake over repeated 4-year periods among a large cohort of health professionals, followed for 24 years. They found very slight increases in weight (mostly less than one-half pound over a four-year period) for subjects consuming alcoholic beverages; these were statistically significant for regular beer and liquor, but not for wine or light-beer. Overall, the largest increases in weight (still, only an increase of 0.6 pounds) were seen for subjects increasing their alcohol by an average of 2 or more drinks/day. For subjects decreasing their alcohol intake over the periods, there was a slight decrease in weight, still only about one-half pound or less.
The investigators conclude that any effects of drinking on weight are very minor, and probably of no clinical significance. While effects on weight gain were slightly lower among consumers of wine and light beer than for those consuming regular beer or spirits, the differences were not large. The study does not present data on the mechanisms of such associations.
Forum members considered this to be a very well-done analysis of repeatedly collected exposure and outcome data among health professionals over an extended period of time. Adjustments were made for known potential confounders associated with changes in weight and appropriate sensitivity analyses were done. While the paper indicates that calories from alcohol are metabolized similarly to those from other foods and do affect weight change, the changes associated with moderate alcohol intake appear to be very minor and would be expected to have very little effect on the development of obesity.
Reference: Downer MK, Bertoia ML, Mukamal KJ, Rimm EB, Stampfer MJ. Change in Alcohol Intake in Relation to Weight Change in a Cohort of US Men with 24 Years of Follow-Up. Obesity 2017;25:1988-1996. doi:10.1002/oby.21979