Study Examines Effect of Low-Carb Diets on Diabetes After Pregnancy

A recent study in Diabetes Care finds that low-carbohydrate diets may not be the best after pregnancy for some women.

In the short run, low-carb diets may help women with gestational diabetes maintain glycemic control. But after pregnancy ends, this type of diet might not be optimal as it could actually contribute to a woman’s progression to type 2 diabetes, especially if her diet has too much animal fat, according to the findings.

The study, led by Cuilin Zhang, MD, MPH, PhD, of the National Institutes of Health, evaluated the cases of 4502 women with a history of gestational diabetes who took part in the Nurses’ Health Study from 1991 to 2011. Their diets were scored based on the amount of animal- or vegetable-based fat they consumed as a part of a low-carbohydrate diet.

Gestational diabetes occurs when the body cannot produce enough insulin during pregnancy to convert blood sugar into energy. It often disappears once a baby is born, but it can raise the risk of developing type 2 diabetes later in life.

Diet information was assessed every 4 years by validated food frequency questionnaires.

The researchers documented 722 cases of type 2 diabetes during 68,897 person years of observation. Multivariable-adjusted hazard ratios (95% confidence interval) of type 2 diabetes, compared the highest and lowest quintiles, were 1.36 for overall low carbohydrate diet (LCD) score, 1.40 for animal LCD score, and 1.19 for vegetable score.

Thus, low-carb diets based on plant-based foods are not significantly associated with a risk of developing type 2 diabetes, but the same cannot be said of animal-based low-carb diets.

Diabetes Care is an official journal of the American Diabetes Association.

Reference

Bao W, Li S, Chavarro JE, Tobias DK, Zhu Y, Hu FB, Zhang C. Low-carbohydrate-diet scores and long-term risk of type 2 diabetes among women with a history of gestational diabetes: a prospective cohort study [published online November 17, 2015]. Diabetes Care. 2015; . pii: dc 151642.