Marriage doesn't just add to your happiness, but also to your waistline, according to a new study. But singles shouldn't boast just yet. German and Swiss researchers surveyed 10,226 people in nine European countries on their marital status and body mass index—a health indicator based on a person’s height and weight—as well as their eating and exercise habits.

The results, which factored in socioeconomic status, age, and nationality, show marriage really does make you pack on the pounds: an extra 4.5 pounds in average-height 5-foot-11 men and 5-foot-5 women, to be precise, reports Medical Daily.

That number is based on an average BMI of 25.7 for single men, compared to 26.3 for married men. Single women had a BMI of 25.1, while the number was 25.6 for married women, per Science Daily.

A normal BMI is 18.5 to 25; 25 to 30 is considered overweight. Though the risk of chronic illnesses like diabetes and cardiovascular disease climb with a person's BMI, the study doesn't actually show single people are healthier.

Married men and women across Austria, France, Germany, Italy, the Netherlands, Poland, Russia, Spain, and the United Kingdom were found to eat better than their single counterparts.

Married couples reported buying more regional and unprocessed foods and less fast food, while married men were more likely to buy organic and fair trade food than single men.

"That indicates that particularly men in long-term relationships are more likely to eat more consciously and, in turn, probably more healthily," the lead author says. But here's the down side: Married men also skimp on physical activity, the author notes, which suggests "couples are not healthier in every respect, as has previously been assumed." (This 1970s marital trend is on the rise.)

This article originally appeared on Newser: Here's How Much Weight Marriage Packs On

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