Background Epidemiological research suggests that alcohol consumption may represent a sizable risk factor for weight gain, though precise causal mechanisms remain unclear and associations inconsistent. Studies focussed on alcohol units have shown linear and J-shaped relationships, with low intensity alcohol consumption associated with lower levels of obesity.

The strength of the alcohol-weight relationship has typically been strongest among men. This gender discrepancy is hypothesised to result from factors including differential drink type preference. While men favour beer, a carbohydrate-rich alcoholic drink, women are more likely to drink wine and therefore consume less energy per unit of alcohol than male drinkers.

The role of alcohol calories has been explored little to date. This study thus set out to determine the association between drink-specific alcohol calorie intake and both overweight and obesity in adults in England.

Methods Survey-adjusted logistic regression models were constructed using data from the Health Survey for England 2006, a nationally representative cross-sectional population survey of the general population resident in private households in England.

Alcohol: Alcohol calories were calculated by multiplying each self-reported drink-specific consumption volume by the total number of calories they were estimated by Drinkaware to contain. Alcohol calories were then categorised according to the quartiles of a person’s sex-specific recommended daily calorie intake (RDA): 1–24%; 25-49%; 50-74%; 75%+ .

Obesity: Body mass index (BMI) was selected as a marker for overweight (≥ 25 kg/m²) and obesity (≥ 30 kg/m²).

Predictors: Risk factors likely to modify the relationship between alcohol calories and BMI were selected a priori. These included demographic variables (age, education, occupation, sex), health and lifestyle variables (physical activity, smoking status), and drink type.

Analyses were restricted to individuals aged 18+ who provided valid data on drink type, alcohol consumption volume and BMI (8864 adults).

Results Mean calorie consumption derived from alcohol on their heaviest drink day in the last week equated to the equivalent of 27% of the RDA calorie intake in men and 19% in women. Individuals in the top alcohol calorie quartile had increased odds of obesity (OR 1.65 [95% CI 1.22, 2.22]) and overweight (1.47 [1.10, 1.97]) relative to the bottom quartile. Consumption only of beer was associated with increased odds of overweight and obesity.

Conclusion Substantial calorie intake is derived from alcohol consumption. This intake is associated with increased odds of overweight and obesity. Awareness of alcohol calories needs to be improved.