Excessive adiposity and gestational
weight gain (GWG) have been linked with maternal and offspring
morbidity. We investigated the relation of maternal diet, physical
activity and GWG on body composition in overweight and obese pregnant
women.

Fat mass (FM) and fat free mass (FFM) of
110 overweight and obese pregnant women were measured by air
displacement plethysmography in early and late pregnancy (mean 13.5 and
35.3 gestational weeks). At the same time points, the quality of overall
diet was assessed by validated index of diet quality (IDQ)
questionnaire (score < 10/15 denotes poor dietary quality and
score ≥ 10/15 denotes good dietary quality), nutrient intakes by 3-day
food diaries, and physical activity by questionnaire. Weight gain
between early and late pregnancy was compared to the gestational weight
gain guidelines issued by Institute of Medicine.

Of
the women, 77% gained more weight than recommended; this was related to
greater dietary fat consumption (80 ± 21 g/day vs. 67 ± 11 g/day,
p = 0.010) and greater increase in FM (2.7 ± 3.0 kg vs. -1.0 ± 2.4 kg,
p < 0.001) compared to women with ideal GWG. Dietary protein intake
(g) correlated positively with FFM at both time points (early pregnancy:
r = 0.31, p < 0.002, late pregnancy: r = 0.39, p < 0.001). Women
with higher dietary quality index score had more FFM, compared to women
with lower dietary quality (early pregnancy FFM: 48.8 ± 5.8 kg vs.
45.8 ± 4.7 kg, p = 0.004, late pregnancy FFM: 56.1 ± 6.4 kg vs.
53.4 ± 5.6 kg, p = 0.025). No correlations were detected between total
energy intake or physical activity and FM or FFM at early or late
pregnancy.

Body composition changes from
early to late pregnancy were related to the amount of weight gained and
overall dietary quality during pregnancy. Higher dietary quality and
protein intake were associated with greater FFM, while dietary fat
intake was related to excess weight gain. Identification of these
dietary determinants of body composition and weight offers new targets
for dietary counseling of pregnant women and thus potential for ensuing
health benefits through reduced adiposity.