Alcohol contains a lot of energy. With 7 kcal per gram it is the second most energy dense nutrient after fat (9 kcal per gram). Does that mean drinking alcohol is associated with overweight and obesity? Results are still inconsistent. A recent meta-analysis1 looks at almost 130 studies and finds different results per study design. Heavy alcohol drinkers have a higher risk of overweight and abdominal obesity than non-alcohol or light drinkers in cross-sectional studies, but this is not the case in cohort studies.
What is already known? A previous systematic review finds that results of studies towards alcohol consumption and obesity are inconsistent.2 Another systematic review only focusing on beer finds that daily consumption of more than 500 ml beer may cause abdominal obesity, but that studies on general obesity are also conflicting.3
What does this study add? This study includes almost 130 studies on the relation between alcohol and overweight and obesity.
Higher risk of overweight with heavy alcohol consumption
The results of all the 127 included studies differ a lot. Cross-sectional studies – where researchers ask people about their alcohol consumption at the same time as they ask about their weight – show a relation between alcohol consumption and a higher risk of overweight and abdominal obesity.
Looking at the amount of alcohol, the studies show that there is only an increased risk of overweight and abdominal obesity for heavy drinking (more than 3 drinks a day) compared to non-drinkers. Contra-intuitively, there is a lower risk of obesity with moderate consumption (1,5 to 3 drinks a day) compared to non-drinkers.
No association in cohort studies
Cross-sectional studies only measure the exposure (alcohol consumption) and the outcome (overweight) at one specific time. That is why these types of studies are not very reliable. Cohort studies try to fix this by following a group of people for a longer time. In this meta-analysis the cohort studies show no relation between alcohol consumption and overweight or obesity.
Obesity
Someone is classified as obese when BMI is higher than 30 kg/m2. In 2016, 390 million women and 281 million men were reported to suffer from obesity4, and it is estimated that 20% of the adults will be obese worldwide in 2030.
Strengths
- A lot of studies included
- Protocol of study was registered beforehand
- Quality of studies are assessed
Limitations
- Not accounted for ex-drinkers
- High heterogeneity
- No differentiation between types of drinks
References
1. Golzarand, M., Salari-Moghaddam, A., & Mirmiran, P. (2021). Association between alcohol intake and overweight and obesity: a systematic review and dose-response meta-analysis of 127 observational studies. Critical Reviews in Food Science and Nutrition, 1-21.
2. Sayon-Orea, C., Martinez-Gonzalez, M. A., & Bes-Rastrollo, M. (2011). Alcohol consumption and body weight: a systematic review. Nutrition reviews, 69(8), 419-431.
3. Bendsen, N. T., R. Christensen, E. M. Bartels, F. J. Kok, A. Sierksma, A. Raben, and A. Astrup. 2013. Is beer consumption related to measures of abdominal and general obesity? A systematic review and meta-analysis. Nutrition Reviews 71 (2):67–87. doi: 10.1111/j. 1753-4887.2012.00548.x.
4. Abarca-Gómez, L., Abdeen, Z. A., Hamid, Z. A., Abu-Rmeileh, N. M., Acosta-Cazares, B., Acuin, C., … & Cho, Y. (2017). Worldwide trends in body-mass index, underweight, overweight, and obesity from 1975 to 2016: a pooled analysis of 2416 population-based measurement studies in 128· 9 million children, adolescents, and adults. The lancet, 390(10113), 2627-2642.