People who drink small amounts of alcohol regularly are less likely to be obese than people who do not drink at all. A study published today in the open access journal BMC Public Health shows that consuming no more than a drink or two a few times a week reduces the risk of being obese. Consuming four or more drinks per day, however, increases the risk of being obese by 46%.
Ahmed Arif, from Texas Tech University Health Sciences Center, in Lubbock, USA and James Rohrer, from Mayo Clinic, Rochester, USA, analysed the results of the National Health and Nutrition Examination Survey III in a subset of 8,236 non-smoker respondents. The respondents had all filled a questionnaire about their drinking habits and their body mass index (BMI) had been measured.
Out of the sample studied, 46% were ‘current drinkers’ and drank at least one drink a month on average. Individuals who drank four or more drinks per day were classified as heavy drinkers. Obesity was defined as a BMI equal to or higher than 30.
The results of the study show that current drinkers had 0.73 lower chances of being obese than non-drinkers. Current drinkers who drank one to two glasses regularly, but less than five drinks per week, were significantly less likely to be obese than non-drinkers and heavy drinkers. Heavy drinkers were 46% more likely to be obese than non-drinkers.
The mechanisms of the protective effect of alcohol on obesity are not well understood and the authors emphasise that “the data give no evidence to advise non-drinkers to start drinking alcohol just for reducing body weight.”
They add: “However, the evidence reported here argues against a strategy of promoting complete abstention at least among those who regularly consume alcohol.”
From BioMed Central
They add: “However, the evidence reported here argues against a strategy of promoting complete abstention at least among those who regularly consume alcohol.”
Consider the following scenario/obvious source of bias:
1) 50 year old man is obese and is told by doctor that alcohol is part of cause
2) 50 year old man stops drinking
3) Obese 50 year old man marks “Not a current drinker” on survey
4) Risk of obesity in analysis goes up for “Not a current drinker” group
This mistake is reported over and over and over and over…
“The mechanisms of the protective effect of alcohol on obesity are not well understood…”
The study did not find a “protective effect of alcohol on obesity.” It found that there is an association between those that are not drinking and those that are obese. There is no causality implied, there is no direction of the association, and in fact, there may be a very nice latent explanation for both conditions:
diabetes.