Location: Arkansas Children's Nutrition CenterTitle: Differences in resting metabolic rate and physical activity patterns in lean and overweight/obese pregnant women Author
Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: 12/15/2011
Publication Date: 4/1/2012
Citation: Ruebel, M., Shankar, K., Badger, T.M., Andres, A. 2012. Differences in resting metabolic rate and physical activity patterns in lean and overweight/obese pregnant women. The Federation of American Societies for Experimental Biology Journal. 26 (Meeting Abstracts):113.1. Interpretive Summary: This study looked at the differences of resting metabolic rate, which is energy required for vital body functions during rest, and physical activity levels of lean and overweight/obese pregnant women. Our results indicated that overweight/obese women had lower resting metabolic rates and physical activity levels compared to lean women. These decreases could indicate a greater risk of weight gain throughout the remainder of pregnancy and after pregnancy.
Technical Abstract: Energy requirements vary during pregnancy due to changes in physical activity (PA) and maternal fat stores. This study measured resting metabolic rate (RMR) and PA patterns in healthy lean and overweight/obese (OW) pregnant women. RMR was measured using indirect calorimetry (MOXUS), activity patterns were estimated by omnidirectional accelerometers (Actical®) and body composition was measured using air displacement plethysmography (BodPod®). Nineteen pregnant women including 12 lean (BMI 18.5-24.9 kg/m2) and 7 OW (BMI 25-35 kg/m2) were assessed at 6-10, 12 and 24 weeks (wk) of gestation. Absolute RMR differed significantly between lean and OW women (1438 ± 49 vs. 1753 ± 62 kcal/day, p<0.05) at 6-10 wk. Moreover, when adjusted for weight, RMR (kcal/kg/d) differed (p<0.05) throughout pregnancy for lean and OW women (23 +/- 1 vs. 21 ± 1, 24 +/- 1 vs. 20 +/- 1, 22 +/- 1 vs.19 +/- 1 at 6-10, 12 or 24 wk, respectively). RMR was also positively correlated with fat mass and fat free mass in both groups (r=0.77, and r= 0.52, respectively, p<0.05). Although not significant, lean women spent ~50 more minutes in moderate to vigorous and 150 less minutes in sedentary time compared to the OW over the 24 wk. In conclusion, OW women had lower RMR (kcal/kg/d) and decreased PA compared to lean women, suggesting a greater risk of excessive gestational weight gain and post partum weight retention.