It's common wisdom that moms-to-be should be getting more calories—if not quite eating for two. But for certain women, it may be safe to cut calories during pregnancy. Obstetrician Raul Artal, M.D., of Saint Louis University in Missouri, studied 96 obese pregnant women with gestational diabetes and instructed 39 of them to exercise and follow a weight-maintenance diet; the others ate the usual diet prescribed for gestational diabetes and didn't exercise. The exercisers used a treadmill or semi-recumbent bike once a week under supervision and worked out on their own at home for an average of 30 minutes daily. Significantly more exercisers maintained their weight or even lost some without harming themselves or their fetus.
Babies born to these mothers were less likely to be oversized than those born to the non-exercisers. Moreover, limiting the mothers' weight gain could help them retain fewer pounds after pregnancy and reduce their risk of Type II diabetes and other weight-related health problems, Artal said.
"The common thought has been that if you're pregnant, you don't even try to lose weight," says Melinda Johnson, M.S., R.D., a spokesperson for the American Dietetic Association. "This study shows you can have a healthy pregnancy even if you start out at an unhealthy weight."
Every pregnant woman should discuss nutrition and appropriate weight gain with her doctor, adds Johnson. And she cautions that the dieting in this study applied only to obese women with gestational diabetes. "This study was of a very specific population," she says. "You can't apply it to any others."