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


METHODS
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 ± SD: 39.3 ± 1.1 compared with 37.9 ± 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 ± 0.8 compared with 34.2 ± 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 [-2.5 (-5.5, -0.7) compared with -0.4 (-1.4, 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.
Division of Endocrinology, Children's Hospital Boston, Boston, MA, USA.
Erinn T
ET
Rhodes
Dorota B
DB
Pawlak
Tamara C
TC
Takoudes
Cara B
CB
Ebbeling
Henry A
HA
Feldman
Margaret M
MM
Lovesky
Emily A
EA
Cooke
Michael M
MM
Leidig
David S
DS
Ludwig
D000328:Adult; D001724:Birth Weight; D002097:C-Reactive Protein / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood; D005260:Female; D005865:Gestational Age; D038321:Glycemic Index; D006257:Head / Q000033:anatomy & histology*; D006801:Humans; D007231:Infant, Newborn; D008055:Lipids / Q000097:blood*; D009765:Obesity / Q000097:blood / Q000178:diet therapy*; D050177:Overweight / Q000097:blood / Q000178:diet therapy; D010865:Pilot Projects; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000178:diet therapy*; D016037:Single-Blind Method; D014280:Triglycerides / Q000097:blood
D008055:Lipids; D014280:Triglycerides; D002097:C-Reactive Protein; D002784:Cholesterol