Effects of a low–glycemic load diet in overweight and obese pregnant women: a pilot randomized controlled trial

Abstract

Background: The optimal diet for pregnancy that is complicated by excessive weight is unknown. Objective: We aimed to examine the effects of a low-glycemic load (low-GL) diet in overweight and obese pregnant women. Design: We randomly assigned 46 overweight or obese pregnant women to receive a low-GL or a low-fat diet. Participants received carbohydrate-rich foods, fats, and snack foods through home delivery or study visits. The primary outcome was birth weight z score. Other endpoints included infant anthropometric measurements, gestational duration, maternal weight gain, and maternal metabolic parameters.Results: There were no significant differences in birth weight z score or other measures of infant adiposity between groups. However, in the low-GL compared with the low-fat group, gestational duration was longer (mean 6 SD: 39.3 6 1.1 compared with 37.9 6 3.1 wk; P = 0.05) and fewer deliveries occurred at 38.0 wk (13% compared with 48%, P = 0.02; with exclusion of planned cesarean deliveries: 5% compared with 53%; P = 0.002). Adjusted head circumference was greater in the low-GL group (35.0 6 0.8 compared with 34.2 6 1.3 cm, P = 0.01). Women in the low-GL group had smaller increases in triglycerides [median (interquartile range): 49 (19, 70) compared with 93 (34, 129) mg/dL; P = 0.03] and total cholesterol [13 (0, 36) compared with 33 (22, 56) mg/dL, P = 0.04] and a greater decrease in C-reactive protein [22.5 (25.5, 20.7) compared with 20.4 (21.4, 1.5) mg/dL, P = 0.007]. Conclusions: A low-GL diet resulted in longer pregnancy duration, greater infant head circumference, and improved maternal cardiovascular risk factors. Large-scale studies are warranted to evaluate whether dietary intervention during pregnancy aimed at lowering GL may be useful in the prevention of prematurity and other adverse maternal and infant outcomes. This trial is registered at clinicaltrials.gov as NCT00364403.Am J Clin Nutr 2010;92:1306-15.

Normalizing Metabolism in Diabetic Pregnancy: Is It Time to Target Lipids?

“…The short-term (4 days) use of a lowcarbohydrate diet in women with GDM resulted in increased free fatty acids and a trend to increased maternal fasting triglycerides with no change in insulin response to a 50-g load while on each diet (40). Overweight and obese pregnant women randomized to either a low glycemic load or low-fat diet from 19 weeks gestation onward showed a greater increase in maternal total cholesterol and smaller increase in maternal triglycerides in those on a low-glycemicload diet from early to late pregnancy (41). There was no difference in gestationadjusted infant birth weight or infant anthropometry but a greater infant head circumference in infants in the lowglycemic-load group (41).…”

“…Overweight and obese pregnant women randomized to either a low glycemic load or low-fat diet from 19 weeks gestation onward showed a greater increase in maternal total cholesterol and smaller increase in maternal triglycerides in those on a low-glycemicload diet from early to late pregnancy (41). There was no difference in gestationadjusted infant birth weight or infant anthropometry but a greater infant head circumference in infants in the lowglycemic-load group (41). Dietary modification aimed at weight reduction can alter maternal lipids, and the lowglycemic-index, low-carbohydrate diet frequently used in the management of diabetes in pregnancy may have differential effects on maternal cholesterol, free fatty acids, and triglycerides.…”

Enablers of and barriers to making healthy change during pregnancy in overweight and obese women

“…[3][4][5] Observational studies suggest that among women who are overweight or obese, healthy diet and lifestyle during pregnancy has been associated with improved maternal cardiovascular function and reduced risk of their infant being born large for gestation. 6,7 Furthermore, physical activity during pregnancy has been associated with a reduced risk of gestational diabetes, pre-eclampsia, preterm birth and operative birth. [8][9][10][11] Pregnancy has been considered a "teachable moment", which may motivate women to change their eating and exercise habits.…”

Maternal Dietary Nutrient Intake and Risk of Preterm Delivery

“…For example, dietary glycemic index has been associated with birth outcomes such as growth retardation, 24 but we are unaware of any previous studies of its association with preterm delivery, except for one small trial of a low glycemic load diet among overweight and obese women. 25 Its investigation is plausible, however, given that increasing glucose levels, within ranges below levels that are diagnostic of diabetes, have been associated with preterm delivery, 26 and dietary glycemic index correlates with glycemic control in pregnant women. 27 As noted, several studies have examined the association of folate with preterm delivery, but other nutrients involved in one-carbon metabolism (e.g., other B vitamins, methionine) have not to our knowledge been investigated.…”