Effects of low-glycemic-index diets in pregnancy on maternal and newborn outcomes in pregnant women: a meta-analysis of randomized controlled trials.
OBJECTIVE
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.
Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, 199 Renai Road, Dushu Lake Higher Education Town, Suzhou, 215123, China.
Ru
R
Zhang
Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, 199 Renai Road, Dushu Lake Higher Education Town, Suzhou, 215123, China.
Shufen
S
Han
Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, 199 Renai Road, Dushu Lake Higher Education Town, Suzhou, 215123, China.
Guo-Chong
GC
Chen
Department of Nutrition, First Hospital of Hebei Medical University, Shijiazhuang, 050031, China.
Zeng-Ning
ZN
Li
Nutrition and Health Research, Nestlé Research Center, Lausanne, Switzerland.
Irma
I
Silva-Zolezzi
Nestlé Research Center, Beijing, 100095, China.
Gerard Vinyes
GV
Parés
Nestlé Research Center, Beijing, 100095, China. yi.wang@rd.nestle.com.
Yi
Y
Wang
Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, 199 Renai Road, Dushu Lake Higher Education Town, Suzhou, 215123, China. qinliqiang@suda.edu.cn.
Li-Qiang
LQ
Qin
D000293:Adolescent; D000328:Adult; D001724:Birth Weight; D001786:Blood Glucose / Q000032:analysis; D004032:Diet; D005215:Fasting; D005260:Female; D047109:Fetal Development; D005320:Fetal Macrosomia / Q000453:epidemiology; D005865:Gestational Age; D038321:Glycemic Index; D006801:Humans; D007231:Infant, Newborn; D039382:Maternal Nutritional Physiological Phenomena; D008431:Maternal-Fetal Exchange; D008875:Middle Aged; D011247:Pregnancy; D011256:Pregnancy Outcome; D016032:Randomized Controlled Trials as Topic; D015430:Weight Gain; D055815:Young Adult
D001786:Blood Glucose
Low glycemic index; Meta-analysis; Pregnancy outcomes; Randomized controlled trials