Prospective Changes in Energy Intake, Physical Activity, and Resting Energy Expenditure during Pregnancy
Background and Purpose: Prenatal changes in energy intake (EI), physical activity (PA), and resting energy expenditure (REE) are important determinants of future health and obesity outcomes. This study examined changes in EI, PA and REE in 16 adult, pregnant women (75% Normal-weight, 15% overweight/obese) early in pregnancy (<16 weeks), mid-pregnancy (24 weeks) and late-pregnancy (32-weeks). Results: From early to mid-pregnancy, women gained an average of 3.7 ± 2.9 kg; EI remained relatively constant (-74 ± 826 kcal/d), PA levels declined by -574 ± 1180 Metabolic Equivalent (METS)*min/wk, and REE increased 122 ± 326 kcal/d. From mid-pregnancy to late-pregnancy, women gained 5.9 ± 2.4 kg; EI increased by 279 ± 352 kcal/d, PA levels increased (460 ± 2000 METS*min/wk) but remained 393 METS*min/wk below early in pregnancy, and REE increased by 251 ± 218 kcal/d. Weight gain trajectories were consistent with IOM recommendations for healthy gestational weight gain (GWG). Conclusions: Findings suggest among women with health GWG, a pattern of gradual and relatively small increases in reported EI and REE is expected, with marginal declines in PA throughout pregnancy. Future research with a larger sample size should identify specific caloric and exercise goals associated with healthy GWG and pregnancy health outcomes.