There are plenty of benefits to being married, but staying trim isn’t one of them, evidently.

A new multi-nation study published in the journal Social Science & Medicine has found that married couples have a higher body mass index (BMI), on average, than singles.

The findings, by researchers at the University of Basel and the Max Planck Institute for Human Development, are based on analysis of more than 10,000 men and women from nine countries — Austria, France, Germany, Italy, the Netherlands, Poland, Russia, Spain, and the United Kingdom.

Although the research found that married couples tend to eat healthier meals than singles, they also tend to weigh significantly more and exercise less.

According to the World Health Organization, a normal BMI is between 18.5 and 25. Overweight is defined as an index between 25 and 30, and obesity as above 30.

The average BMI of single men in the study was 25.7; that of married men was 26.3. For women, the average index was 25.1 for singles and 25.6 for married women.