The research, conducted by UKMedix.com, has revealed the effect that a women's frame of mind can have on her weight.
The study also found that the average woman will gain 7.2 pounds or 3.2 kg in the first year of a new relationship. However, just under half put blame on their partner's poor diet as the reason for weight gain, reports femalefirst.co.uk.
"It seems that our frame of mind has a huge impact on our weight, and although men seem to lose weight when in a happy relationship, the average woman will gain half a stone," said Sarah Bailey of UKMedix.com. One stone, an old British measure, is 6.35 kg.
"Being comfortable in our love lives often equates to increased self-confidence, perhaps explaining the weight gain that many experience." she added.