Working mothers need a solid relationship with their partners to stay fit. Single mothers, the study found, did not fare so well.

Mothers who work, they have discovered, stay in better shape than those who do not.

In fact, said researchers, it is homemakers who suffer the most -- they are less healthy and more likely to be overweight.

Anne McMunn, of University College London, one of the authors of the study published in the British Medical Journal's Journal of Epidemiology and Community Health, said the research -- based on decades of evidence -- proved women "could have it all."

Single Mothers Less Fit

She said: "Women who combine work with children and marriage do have better health. It's not the case that women who work have worse health. While it may be stressful for them at the time, their longterm health is better when they have a combination of roles. Combining work with family life is actually good for women's long-term health."

Dr. McMunn stressed that the research found that good health was more likely down to combining different roles rather than healthy women simply taking on those roles.

However, she warned that working mothers needed a solid relationship with their partners to stay fit. Single mothers, the study found, did not fare so well.

The work from Dr McMunn and her colleagues is based on extensive evidence gathered by a team that has been tracking the long-term health of British men and women born in 1945.

Homemakers Report Worst Health

The Medical Research Council's National Study of Health and Development quizzed men and women about their health when they were 26 and 54. Information about the women's employment history, marital status, and whether they had children was also collected for every decade from the age of 26, alongside weight and height.

The research found that by the age of 54, a woman who had a partner, was a mother, and who had worked was significantly less likely to report ill health than women who did not fulfil all three roles.

Women who had been homemakers for all or most of their lives and had not had a regular job were most likely to say their health was poor, followed by lone mothers and childless women. The study found nearly two out of five long-term homemakers were obese by their 50s, compared with just under a quarter of women who had fulfilled all three roles. Dr McMunn said many of the women in the study had taken a career break to have children and then gone back to work.

What About Children?

But this was simply a reflection of the culture in which the women had their children and did not mean that women who worked while their children were young suffered, she said.

"Nearly half of those who combined work and children were working all the time their children were growing up, " she said. "They were part of the group who had good health."

Dr. McMunn and her fellow authors studied responses from 1,781 women, all of whom were born in the first week of March 1946.

So the women studied were having their families -- and starting their careers -- just as society fretted most about working mums, in the 1960s and 1970s, and when attitudes to working women were very different to today.

The study does not look into the comparative wellbeing of children brought up by working and stay-at-home mothers.