While many couples attempt to lose weight in the lead up to their wedding, a new study has found that after the big day, happy newlyweds are more likely to gain weight, which can affect their overall health.

According to US psychologist, Dr Andrea Meltzer, the findings suggest that people who are satisfied in their marriage relax their efforts to maintain or lose weight because they do not feel like they need to attract an alternative partner.

"On average, spouses who were more satisfied with their marriage were less likely to consider leaving their marriage, and they gained more weight over time. In contrast, couples who were less satisfied in their relationship tended to gain less weight over time," Dr Meltzer explained.

She looked at 169 newlywed couples in their first marriage. Their weight and marital satisfaction was monitored over a four-year period.

Most research in this area has found that marital satisfaction is associated with good health behaviours.

"For example, studies have found that satisfied couples are more likely to take medications on time and schedule annual physicals. Yet the role of marital satisfaction and actual health is less clear," Dr Meltzer noted.

Her research revealed that people who were not happy in their marriage were more likely to consider leaving their spouse and on average, gained less weight over time.

She said this suggests that people ‘perhaps are thinking about their weight in terms of appearance rather than health'. Young couples should therefore be encouraged to think about their weight in relation to their overall health.

"We know that weight gain can be associated with a variety of negative health consequences, for example diabetes and cardiovascular disease. By focusing more on weight in terms of health implications as opposed to appearance implications, satisfied couples may be able to avoid potentially unhealthy weight gain over time in their marriages," Dr Meltzer said.

Details of these findings are published in the journal, Health Psychology.