New studies have just concluded that couples tend to gain weight the happier that they are.

Researchers found that people who are single try and remain thinner so that they can find the best possible mate. Once they have found this person, they tend to lose some of the motivation that they had before to eat healthy and work out.

Once we really fall in love with someone, it’s really because of what’s in their soul, so we care less and less about their outer appearance. This causes us to let our guards down and pack on the pounds.

OnePoll survey that was commissioned by Jenny Craig observed 2,000 people and found that the average respondent gained about 36 pounds after dating their partner. The study found individuals who were in  relationships tend to gain 17 pounds in the first year alone.

The study found that 69 percent of men were more likely to gain weight in the first year of a relationship compared to 45 percent of women. Another 34 percent of respondents said that they gained weight from ordering takeout or cooking at home while drinking together.

The main reason people gave for gaining weight was a sense of comfort that they didn’t have when they were single, with around 65 percent saying that they did not feel any pressure to look their best since they had found a partner. It only takes couples aged 18-24 an average of 10 months to reach this “comfort zone,” while it typically takes people between the ages of 45 and 54 around a year and a half.

Couples are also more likely to have weight gain in marriage, with many people saying they gained weight in the first five years of being married. However, it should be noted that it was the happiest couples who gained weight.

One study conducted by the U.S. National Library Of Medicine National Institutes Of Health looked at couples that had been married for four years and studied their emotional health and levels of stress. The researchers concluded that the happiest couples were twice as likely to gain weight as those who were less happy.

“These findings challenge the idea that quality relationships always benefit health, suggesting instead that spouses in satisfying relationships relax their efforts to maintain their weight because they are no longer motivated to attract a mate,” the study concluded. “Interventions to prevent weight gain in early marriage may, therefore, benefit from encouraging spouses to think about their weight in terms of health rather than appearance.”

Researchers have advised couples to exercise and eat healthy with their partner, as this is the best way to keep from gaining weight.

“We know that close relationships affect the health outcomes of individuals,” said Dr. Pamela Peeke, Assistant Clinical Professor at University of Maryland School of Medicine. “This data is a clear indicator that couples who support each other in a healthy lifestyle together can reap the benefits of happiness together as well.”