The Real Skinny on Marriage and Weight

Couples may have higher body mass index rates than singles

Marriage may not just add to your happiness, it may also add to your waistline.

A new study from from the University of Basel in Switzerland found that couples — whether married or living together — tended to weigh more than singles. Couples were also less likely to engage in sports.

“Our findings show how social factors can impact health," said study author Ralph Hertwig, the director of the Center for Adaptive Rationality at the Max Planck Institute for Human Development in Berlin, Germany, in a press release. "In this case, that the institution of marriage and certain changes in behavior within that context are directly related to nutrition and body weight."

These researchers interviewed more than 10,000 people from nine European countries about their dietary and exercise habits.

Dr. Hertwig and team found that couples generally had healthier diets than the singles.

For example, couples reported buying more regional, unprocessed products and less convenience food than singles. Married men were also more likely than single men to buy organic and fair trade food.

"That indicates that particularly men in long-term relationships are more likely to eat more consciously and, in turn, probably more healthily," said lead study author Jutta Mata, an assistant professor of health psychology at the University of Basel, in a press release. "But our findings indicate that couples are not healthier in every respect, as has previously been assumed.”

However, both men and women — who were either married or were living with a partner — had a higher body mass index (BMI) than their single counterparts.

BMI is a measure of body fat based on weight and height. A normal BMI falls between the range of 18.5 and 25.A higher than normal BMI may increase the risk of obesity-related diseases. In this study, the average BMI for married men was 26.3 and 25.6 for married women. The average BMI for single men was 25.6 and 25.1 for single women.

This study was published online in the July issue of the journal Social Science and Medicine.

No funding sources or conflicts of interest were disclosed.