It is a common myth that people who are overweight can drink more. Understand why this is not true.

Alcohol, Calories, and Obesity: What Does the Scientific Evidence Say

The consumption of alcoholic beverages provides significant calories to the diet and may influence the risk of weight gain and obesity. Recent scientific studies show that this relationship is complex: while low alcohol intake is not always associated with weight gain, higher levels of consumption are linked to a greater likelihood of overweight and obesity, especially abdominal obesity.

Obesity is currently one of the main public health challenges worldwide. It is associated with cardiovascular diseases, diabetes, cancer, and reduced life expectancy. Among the various factors contributing to weight gain, alcohol consumption has received increasing attention from the scientific community.

Alcohol provides approximately 7 kcal per gram, an energy value close to that of fat (9 kcal/g) and higher than that of carbohydrates and proteins, both with 4 kcal/g. These calories can contribute to a positive energy balance, especially when consumption is frequent or in large amounts¹.

A comprehensive review published in the journal Critical Reviews in Food Science and Nutrition, which analyzed 127 observational studies, investigated the relationship between alcohol intake and excess weight¹. The results indicated that, in cross-sectional studies, alcohol consumption was associated with a higher likelihood of overweight and abdominal obesity. When the analysis considered the amount consumed, high intake (above 28 g of alcohol per day) was associated with a greater probability of overweight and abdominal obesity compared to non-drinkers or light drinkers. In contrast, light consumption did not show a consistent association with obesity in cohort studies.

Another meta-analysis, published in the Journal of Epidemiology and Public Health, specifically evaluated adults and found that alcohol consumption was associated with approximately a twofold increase in the likelihood of obesity in the studies included in the analysis². The study also highlighted that age influences this risk, as metabolism and physical activity patterns tend to change over the course of life.

Beyond the caloric aspect, more recent research suggests that the relationship between alcohol and obesity may go beyond simply counting calories. An article published in the journal Molecular Psychiatry discusses how alcohol and obesity share similar biological mechanisms, involving brain reward circuits, appetite regulation, gut hormones, and systemic inflammation³. This means that alcohol consumption may influence eating behavior, the feeling of satiety, and even preferences for higher-calorie foods.

Another relevant point is that alcohol can affect liver metabolism and promote fat accumulation in the liver, especially when consumed excessively. When combined with excess weight, the risk of liver disease increases significantly³. Studies show that the combination of obesity and high alcohol consumption can accelerate the development of liver diseases.

It is important to note that results vary according to the pattern of consumption. Light or occasional drinking does not show a consistent association with obesity in longitudinal studies¹. On the other hand, heavy and regular consumption is more frequently associated with weight gain and abdominal obesity, a type of body fat that carries greater cardiometabolic risk.

From a public health perspective, these findings reinforce that alcohol should be considered not only for its effects on the liver, brain, and risk of dependence, but also as a relevant source of calories in the diet. Reducing excessive consumption may contribute not only to a lower risk of alcohol-related diseases, but also to better body weight control.

In summary, scientific evidence indicates that:

• Alcohol provides significant calories and may contribute to a positive energy balance.
• High consumption is associated with a greater likelihood of overweight and obesity, especially abdominal obesity.
• Light consumption shows inconsistent results regarding obesity risk.
• Alcohol and obesity share biological mechanisms related to appetite regulation and reward.

The relationship between alcohol and obesity depends on dose, frequency, drinking pattern, and individual characteristics. Informing the public about this evidence is essential for making informed health decisions.

References

1. Golzarand M, Salari-Moghaddam A, Mirmiran P. Association between alcohol intake and overweight and obesity: a systematic review and dose-response meta-analysis of 127 observational studies. Crit Rev Food Sci Nutr. 2021. doi:10.1080/10408398.2021.1925221
2. Wulandari AN, Hanida AN. Meta-Analysis: Relationship between Alcohol Consumption and Age on Obesity in Adults. J Epidemiol Public Health. 2022;7(2):153–166. doi:10.26911/jepublichealth.2022.07.02.01
3. Leggio L, Farokhnia M, Kenny PJ, Pepino MY, Simmons WK. Crosstalk between alcohol use disorder and obesity: two sides of the same coin? Mol Psychiatry. 2025;30:5938–5952. doi:10.1038/s41380-025-03259-8