Skip to content

Health & Pregnancy

Font Size

Pre-Pregnancy Dieters Gain Too Much Weight

Women Who Diet Before Pregnancy Gain the Most Weight While Pregnant
WebMD Health News
Reviewed by Louise Chang, MD

Oct. 1, 2008 -- Women who diet before pregnancy tend to gain too much weight during pregnancy.

Even women who succeed in controlling their weight before pregnancy tend to gain too much weight while they're carrying a child, say Anna Maria Siega-Riz, PhD, RD, and colleagues at the University of North Carolina at Chapel Hill.

"When they are not pregnant, many women are really trying to hold their weight down. But when they become pregnant the message they get is 'Eat for two; give in to your cravings,'" Siega-Riz tells WebMD.

The UNC researchers asked 1,223 women who had just become pregnant about their previous dietary habits. About half the women had restrained their eating habits in some way. They simply cut back on what they ate, followed specific diet plans, and/or cycled between gaining and losing weight.

Regardless of how they did it, all normal-weight, overweight, or obese women who had tried to restrict their diets gained more weight during pregnancy than did women who did not diet before pregnancy.

Moreover, the pre-pregnancy dieters gained more weight during pregnancy than doctors recommend -- putting themselves and their babies at risk.

Women who gain too much weight during pregnancy have more C-sections, more preeclampsia, and are more likely to have babies with growth problems, says obstetrician J. Christopher Glantz, MD, MPH, director of the perinatal outreach program at the University of Rochester Medical Center.

"You might think people who are dieting before pregnancy would tend to gain less weight. Not only is that not true, this study shows that in pretty much all weight categories, the restrained eaters seem to gain more weight once they get pregnant," Glantz tells WebMD.

Surprisingly, normal-weight women don't need much more food once they're pregnant:

It's a different story only for women who are underweight before pregnancy, but who restrict their diets anyway. These women, Siega-Riz and colleagues found, did not gain enough weight during pregnancy -- and many likely suffer from eating disorders.

Pregnancy Week-By-Week Newsletter

Delivered right to your inbox, get pictures and facts on
what to expect each week of your pregnancy.

Today on WebMD

hand circling date on calendar
Track your most fertile days.
woman looking at ultrasound
Week-by-week pregnancy guide.
Pretty pregnant woman timing contaction pains
The signs to watch out for.
pregnant woman in hospital
Are there ways to do it naturally?
slideshow fetal development
pregnancy first trimester warning signs
What Causes Bipolar
Woman trying on dress in store
pregnant woman
Close up on eyes of baby breastfeeding
healthtool pregnancy calendar
eddleman prepare your body pregnancy

WebMD Special Sections