Snoozing May Help Women Shed Baby Weight

July 25 -- FRIDAY, July 24 (HealthDay News) -- New moms who can't zip up their pre-pregnancy jeans might not be catching enough zzzs.

Getting a good night's sleep, in fact, may be just as important as diet and exercise for shedding baby weight.

One study of new mothers found that those who slept five or fewer hours a day six months after giving birth were three times as likely to hold onto those extra pounds as were women who got seven or more hours of sleep.

Short sleep duration "stood out as an independent risk factor" for weight retention, said Erica P. Gunderson, a research scientist and epidemiologist at Kaiser Permanente in Oakland, Calif., who worked on the study.

For many women, postpartum weight retention is a serious issue because it can lead to long-term weight gain. Some studies show that up to 20 percent of women retain at least 11 pounds at six to 18 months after giving birth, Finnish researchers reported.

Lifestyle factors that lead to postpartum weight retention -- including a woman's diet, physical activity and sleep patterns -- have not been well studied, researchers report. But as every bleary-eyed new mother knows, slumber is frequently disrupted or cut short in the first year after a baby's birth.

"Sleep deprivation can cause changes in the levels of hormones involved in appetite regulation," explained Dr. Sirimon Reutrakul, a clinical associate in medicine at the University of Chicago Medical Center.

"Keep in mind, though, that there are multiple factors involved in causing postpartum women to sleep less," she said. "These include just having a newborn, having other small children at home, possible postpartum depression, illness of the newborns, if any, work, etcetera," she said.

In Gunderson's study, the sleep and weight retention patterns of 940 Massachusetts women were analyzed. A year after giving birth, 124 of the women had retained 11 or more of the pounds they had put on during their pregnancy.