Effects of low-glycemic-index diets in pregnancy on maternal and newborn outcomes in pregnant women: a meta-analysis of randomized controlled trials.

PURPOSE: Maternal diet with a high glycemic index (GI) is associated with fetal overgrowth and higher infant body adiposity. Effects of low-GI diet on maternal and newborn outcomes have been assessed in both healthy pregnancy and gestational diabetes mellitus, but the results remain inconclusive. This meta-analysis aimed to examine the effects of low-GI diets on maternal and newborn outcomes. METHODS: PubMed, Clinical Trials, and Cochrane Library databases were searched for relevant randomized trials up to January 2016. Random- or fixed-effects models were used to calculate combined treatment effects. RESULTS: A total of 11 trials involving 1985 women were eligible for analysis. This meta-analysis assessed 7 maternal and 11 newborn outcomes. Of these, gestational weight gain (GWG), fasting blood glucose (FBG), newborn birth weight, ponderal index (PI), proportion of macrosomia, and large for gestational age (LGA) were investigated in more than 8 trials. Compared with control diets, low-GI diets significantly reduced FBG (weight mean differences (WMD) = -0.18 mmol/L, 95 % CI: -0.33, -0.02), 2-h postprandial glucose level (WMD = -0.33 mmol/L, 95 % CI: -0.54, -0.12), and the proportion of LGA (RR = 0.52, 95 % CI: 0.31, 0.89). A lower GWG (WMD = -0.69 kg, 95 % CI: -1.74, 0.36) and birth weight (WMD = -0.10 kg, 95 % CI: -0.23, 0.03) were also observed without significant differences. Heterogeneity was observed in the GWG, FBG, and birth weight analyses. Low-GI diets did not affect other maternal and newborn outcomes. In subgroup and sensitivity analyses, the intervention effects of low GI on GWG and FBG varied. CONCLUSIONS: Low-GI diets may have beneficial effects on maternal outcomes for those at risk of developing high glucose levels, without causing adverse effects on newborn outcomes. However, results should be interpreted with caution because of the evidence of heterogeneity and limited number of studies.

Nutrient Intakes of Pregnant Women and their Associated Factors in Eight Cities of China: A Cross-sectional Study.

BACKGROUND: During the last 3 decades, China has dramatic changes of the dietary pattern among its citizens, particularly in urban cities. This study aimed to determine the nutrient intake status and factors associated with nutrient intakes of urban Chinese pregnant women now-a-day. METHODS: The multistage stratified random sampling method was applied in the cross-sectional study. 479 women in three trimesters of pregnancy from eight cities of China were recruited. Nutrient intakes were evaluated with one 24 h dietary recall, and compared with the Chinese Dietary Reference Intakes (DRIs) 2013 for available nutrients. RESULTS: Most pregnant women had imbalanced macronutrient distribution with excessive energy derived from fat. Intakes of Vitamin A, B 6, calcium, magnesium, and selenium were below Chinese Recommended Nutrient Intake (RNI) and Estimated Average Requirements (EARs) in all trimesters. Most pregnant women took more folic acid in the first trimester with a significant decrease in the second and third trimester (P < 0.05). Shortfall in iron intake was found in the third trimester whereas some women may be at the risk of excessive iron intake. Intakes of thiamin met RNI in the first trimester but were below EAR in all trimesters. Trimester phasing was positively associated with most nutrients (P < 0.05). Prepregnancy body mass index was inversely associated with energy, fat, Vitamin C, and calcium intake (P < 0.05). Educational level and household income were positively associated with folic acid intake (P < 0.05). CONCLUSIONS: Current prenatal dietary choices of urban pregnant women in China are imbalanced in the nutrient intake when compared with national DRIs 2013, particularly in intakes of energy derived from fat and micronutrients. Appropriate dietary advice to pregnant women should promote a balanced diet with emphasis on avoidance of foods of high fat content and incorporation of foods that are good sources of the key micronutrients that are usually lacking in a regular pregnancy diet. Further research is needed to understand the eating habits and food patterns that contribute to this imbalanced diet in order to be able to effectively improve prenatal women's nutrient intake status.