Marriage may help keep the pounds off, according to a study conducted at Japan's Yokohama City University.

Researchers studied people with Type 2 diabetes and found that those who were single doubled their risk of being overweight when compared to those who were married.

Researchers examined 270 people with an average age of 65 who had been diagnosed with Type 2 diabetes.

Marriage conferred particular benefits on men, who the study found were 58 percent less likely to have metabolic syndrome, a combination of risks that include obesity, high blood pressure, and diabetes.

"Our findings show that being married and living with one’s spouse reduced the risk of being overweight by approximately 50 per cent among patients with Type two diabetes," the authors wrote.

"Men who were married and lived with their spouse also exhibited a risk reduction of 58 percent for metabolic syndrome," they said.

"In contrast, being single was a risk factor for overweight status and metabolic syndrome, especially among male patients."

Other researchers have found that even the timing of marriage can affect obesity.

People who earn college degrees before marriage are much less likely to become obese than those who marry before they graduate, according to a study published in the Journal of Health and Social Behavior.

"People who get married before they earn a degree from a four-year college are about 65 percent more likely to later become obese than people who get married after college," said Richard Allen Miech, lead author of the study and a research professor at the Institute for Social Research at the University of Michigan.

Other studies have found that marriage offers many health benefits.

A study earlier this year from the University of East Anglia found that married people have higher odds of surviving a heart attack.

Marriage may even help you live longer, according to a study from the University of Rochester, which found that happily married people who underwent heart bypass surgery were three times as likely to survive 15 years as those who were unmarried.

And the merrier the marriage, the higher the long-term survival rate, especially for women.