WEDNESDAY, Oct. 1 (HealthDay News) -- Women with a history of dieting or other practices that restrict their eating habits may be more vulnerable to gaining too much or too little weight during pregnancy, a new study finds.

University of North Carolina researchers, in a study of more than 1,200 women, found these previously restricted eaters tended to gain more than the recommended amount of weight if they were either normal, overweight or obese at the start of pregnancy. Restricted eaters who were underweight at the start of their pregnancy tended to gain less than the recommended amount.

The study, published in the October issue of the Journal of the American Dietetic Association, based the desired weight gain amounts on recommendations made by the Institute of Medicine. The institute says women should gain 28 to 40 pounds if they are underweight, 25 to 35 pounds if normal weight, 15 to 25 pounds if overweight, and at least 15 pounds if obese.

"During pregnancy, it would be useful to target these women with similar nutritional and physical activity strategies in order to avoid excessive weight gain and adverse pregnancy outcomes such as Caesarean sections, Macrosomia, and large-for-gestational age [LGA], as well as shorter duration of breast-feeding and higher weight retention in the postpartum period," study co-author Anna Maria Siega-Riz said in a news release issued by the publisher.

More information

The U.S. Department of Health and Human Services has more about having a healthy pregnancy.