Women who had risk factors for weight gain but were not overweight when they got pregnant were most likely to retain weight if they gained too much during pregnancy.
For those who think pregnancy gives women an excuse to eat what they want, a new study says otherwise.
Excessive weight gain during pregnancy can cause excess body fat and pounds that are never lost, according to a study published this week in The American Journal of Clinical Nutrition.
Researchers from Columbia University studied data from 302 women, all African-American or Dominican mothers who took part in the Columbia Center for Children’s Environmental Health Mothers and Newborns Study between 1998 and 2013. The women taking part were at risk of becoming obese due to socioeconomic factors and unhealthy dietary patterns.
Before pregnancy, the women had an average body mass index (BMI) of 25.6, which is just above the CDC recognized level for being overweight. Of the group, 5% were underweight, 53% were normal weight, 20% were overweight and 22% were already obese.
During pregnancy, 64% put on more weight than the 15-25 pounds recommended by the Institute of Medicine (IOM) guidelines. The women were followed for 7 years after giving birth. The relationship between pregnancy weight gain and the excess weight retained after giving birth varied depending on each woman’s weight before pregnancy; however, those women with relatively low BMI who gained a lot of excess weight during pregnancy were most likely to retain it long after the birth of their child.
For a woman with a prepregnancy weight of 22, which is right at normal weight, excessive weight gain was associated with 3% higher body fat and a 5.6 kg higher postpartum weight retention. For a woman with a prepregnancy BMI of 30–which is the level the CDC defines as obese–excessive weight gain was associated with 0.58% higher body fat and 2.05 kg of postpartum weight retention.
“Gestational weight gain greater than the IOM recommendations has long-term implications for weight-related health,” said Elizabeth Widen, PhD, RD, a nutritional epidemiologist at Columbia’s Maiman School of Public Health and a co-author of this study. "These findings also suggest that normal and modestly overweight women may be more physiologically sensitive to effects of high gestational weight gain and, therefore, need to be further supported to gain weight appropriately during pregnancy.”
IOM guidelines on how much weight women should gain vary depending on their weight at the start of pregnancy. Normal weight women should gain about 25-26 pounds, but overweight women should gain 15-25 pounds. Nearly half (47%) of women exceed the guidelines.
Widen EM, Whyatt RM, Hoepner LA, et al. Excessive gestational weight gain is associated with long-term body fat and weight retention at 7 y postpartum in African American and Dominican mothers with underweight, normal, and overweight prepregnancy BMI [published online October 21, 2015]. Am J Clin Nutr. doi:10.3945/ajcn.115.116939.