Resting Energy Expenditure Relationship with Macronutrients and Gestational Weight Gain: A Pilot Study
Abstract Background: Resting energy expenditure (REE) comprises 60% of total energy expenditure and variations may be associated with gestational weight gain (GWG) or maternal diet. The objective of this study was to examine the impact of ambulatory metabolic tracking on GWG and the association with maternal macronutrient composition during mid-pregnancy. Methods: Pregnant women aged 29.8±4.9 yr (78.6% non-Hispanic, White) with gestational ages (GA) < 17 wk were randomized to Breezing™ (N=16) or control (N=12) groups for 13 wks. REE by Breezing™ indirect calorimetry, anthropometrics and dietary intake were collected every two weeks. Early (GA weeks 14-21), late (GA weeks 21-28), and overall (GA week 14-28) changes in macronutrients and GWG were calculated. Results: Overall total and rate of GWG did not differ by group but Breezing™ women had lower rate and total GWG in the beginning of the second trimester but gained significantly more weight [F(1,24)=5.29, p=0.03] in the latter half. Independent of group assignment, early increases in REE were associated with an increased rate of GWG later in pregnancy (r=0.53, p=0.05). Dietary intake did not differ by group at baseline; however, overall energy (-144±339 vs. 192±422, p=0.03) and protein (-10±24 vs. 13±31, p=0.05) intake were significantly lower for the Breezing than the control women which primarily occurred in the latter half of the second trimester. Conclusion: Regular metabolism tracking alone did not have an impact on GWG. Assessment of REE during pregnancy in conjunction with nutritional counseling or education may result in improvements in GWG.