Marriage Triples Obesity Risk in Men: The Same Effect Is Not Seen in Women

• Worldwide obesity rates have more than doubled since the 1990s.
• Today, more than 2.5 billion adults and children are classified as overweight or obese.
• By 2050, half of adults and a third of children are expected to be overweight or obese.

Although genetic predisposition, poor diet, physical inactivity, environmental toxins and certain diseases are known to be major risk factors for obesity, scientists at the National Institute of Cardiology in Poland wanted to investigate the effect of marriage as well.

Marriage Increases Obesity Risk in Men by 3.2 Times

Researchers examined medical and general health data from 2,405 people with an average age of 50. Statistical analyses identified associations between weight gain and age, marital status, mental health and other factors.

Presented at the European Congress on Obesity in Málaga, Spain, this year, the study found that married men were 3.2 times more likely to be obese than unmarried men. The same did not apply to married women. Marriage also increased the likelihood of being overweight by 62% in men and 39% in women.

These findings support another study conducted in China in 2024, which showed that marriage increased body mass index (BMI) in men during the first five years. The Chinese study found that marriage increased the rate of being overweight in men by 5.2% and the rate of obesity by 2.5%. Similarly, earlier research at the University of Bath found that married men weighed an average of 1.4 kg more than unmarried men.

Obesity Risk Increases With Age

The new study in Warsaw also identified age as an important factor in weight gain. Each additional year of age increased the risk of being overweight by 3% in men and 4% in women, and the risk of obesity by 4% in men and 6% in women.

Factors Affecting Obesity in Women

Researchers noted that some factors increasing obesity risk in women did not have the same effect in men.

• Women with depression had twice the risk of obesity.

• Women with low health literacy had a 43% higher risk of obesity.

• Obesity was more common in women living in small communities.

None of these factors, however, increased obesity risk in men.

Conclusion and Commentary

This study again shows that excess weight does not depend solely on individual choices: social, psychological and environmental factors also play a major role. The risk of being overweight or obese rises with age, particularly for women. In men, lifestyle changes and social expectations associated with marriage may contribute to weight gain.

In men, BMI increases after marriage but decreases before and after divorce. One possible explanation is that unmarried men make more physical effort because they are motivated to find a partner. Another is that married people eat more regular and richer meals because of social obligations.