Does living alone make you thinner?

Score one for the singles crowd. People who live alone tend to be thinner than married couples or co-habitors, according to research out of Western Washington University.

But the difference is, well, slim. On average, single people weighed about three pounds less than their coupled-up counterparts.

The study, which will be published in January in the Journal of Family Issues, examined 20 years of data from more than 3,000 people. Researchers calculated body mass index - a tool often used to measure risk of chronic diseases such as diabetes, heart disease and cancer.

"The results show that living without a partner, either being divorced or never married, is associated with lower body weight," wrote study author Jay Teachman, a sociologist. "Cohabitors and married respondents tend to weigh more."

Perhaps not surprising, people who had broken up with their live-in love lost weight - which Teachman attributed to stress. But that weight loss was temporary.

The findings offer a different spin on the outpouring of research touting the health benefits of married life.