The standard notion of weight gain is related to age but a new study has revealed that women who live with a partner have a tendency of adding 11 extra pounds over a period of 10 years as compared to those women who live alone.

Women who did not give birth and live with partners gained an average of 15 pounds in the same time period, whereas women who had partners and children gained 20 pounds in 10 years.

Any concrete conclusions could not be drawn by researchers at the University of Queensland in Australia due to a lack of enough single mothers in the study. They said that factors like behavior and metabolic changes may be at work.

A total of 6,000 Australian women were followed for 10 years ending in 2006. The women were 18-23 years of age at the beginning of the study and filled up a detailed questionnaire about their health and lifestyle habits at regular intervals.

At the end of the ten year period, half of the women had at least one child and more than half lived with their spouses. Researchers found that most of the extra weight gain observed in mothers was a result of the first child.