Introduction

In the latest battle plan in the UK Government’s war on obesity, it was announced that the Government wanted to make companies add calorie labels to alcoholic drinks so that consumers might make healthier choices. If only it were that simple.

It is plausible that alcohol drinking is related to obesity because alcohol has a relatively high energy content and because people tend to eat more when they drink with meals. However, it is not clear that alcohol drinking is associated with obesity independent of socioeconomic factors – like one’s occupation – and lifestyle choices – such as smoking and physical activity. Scientists like me often say that more research is needed, but that really was the case when we conducted our study.

What makes our study so special?

Alcohol drinking tends to change with age in the UK: there is a rapid increase in consumption in adolescence, a plateau in midlife, and a decline in older age. Nonetheless, most studies of alcohol and obesity only include a measure of alcohol drinking at the start of the study and a measure of obesity at the end of the study. Our study is special because alcohol drinking, body mass index, socioeconomic factors, and lifestyle choices were measured at age 30, age 34, age 42, and age 46 (body mass index uses height and weight to estimate body fat).

What did we find?

We used data from 5,931 men and 5,656 women in the 1970 British Cohort Study. In men, we found that alcohol drinking was associated with body mass index regardless of socioeconomic factors and lifestyle choices. For example, body mass index increased by around 0.38 kg/m2 per year in men who drank 2-3 days a week. Interestingly, the increase in body mass index was lower in men who drank and were physically active in their leisure time.

In women, we found that alcohol drinking was not associated with body mass index independent of socioeconomic factors and lifestyle choices. Giving up smoking was one of the main causes of the increase in body mass index in women. Importantly, the increase in body mass index was much lower in women who gave up smoking and were physically active in their leisure time.

Conclusion and call to action

Our study is better than most because it includes repeated measurements of alcohol drinking, body mass index, socioeconomic factors, and lifestyle choices. Our study suggests that drinking in one’s thirties and forties is associated with body mass index in men, but not in women.

There are many causes of weight gain, and the war on obesity won’t be won by putting calorie labels on alcoholic drinks. Our study suggests that there should be more emphasis on physical activity in the UK Government’s war on obesity. Policies to increase physical activity should be targeted at men who drink and at women who wish to give up smoking because most women gain weight after quitting.

Written by Dr Gary O’Donovan, Universidad de los Andes, Bogotá, Colombia

All IAS Blogposts are published with the permission of the author. The views expressed are solely the author’s own and do not necessarily represent the views of the Institute of Alcohol Studies.