Married women can now blame their husbands for that extra flab as a new study has found that those living with a partner put on more weight than the single ones.

Married women were two kg heavier than their unmarried counterparts and they become four kg heavier after having a baby, said the research published in the American Journal of Preventive Medicine.

The researchers attributed the weight gain to cohabiting women eating unhealthier food because of their partners, while they also have less time to exercise.

Annette Dobson, who co-authored the study along with Wendy Brown and Richard Hockey, said: "This is a general health concern as obesity rates continue to increase.

`Getting married or moving in with a partner and having a baby are events that trigger even further weight gain. We must look at ways to prevent health risks by focusing on the times when women need to be especially careful.`

The research, conducted by the Queensland University in Australia, followed 6,000 women aged between 18 and 23 over a period of 10 years ending in 2006. Each woman periodically completed a survey with questions about weight, height, age, physical activity and alcohol consumption among others, the Daily Telegraph reported.

It found that 10 percent of woman gained five kg when she was single, but she would be seven kg heavier while living with a partner and 10 kg heavier if she had both a partner and a baby.