Poster Topical Area: Maternal, Perinatal and Pediatric Nutrition
Location: Hall D
Poster Board Number: 356
Background: Investigating energy metabolism during the postpartum (PP) period is crucial for better understanding weight regulation at this life stage.
Objective: To profile total energy expenditure (TEE) and its components (resting energy expenditure [REE], exercise energy expenditure [EEE], sleep energy expenditure [SEE], and respiratory quotient [RQ]) of PP women, and to examine the association between energy metabolism and PP weight retention (PPWR).
Methods: Forty-nine PP women participated in this longitudinal observational study. At 3 months PP, participants completed a 30min REE test using whole body calorimetry (WBC) and body composition analyses (dual-energy X-ray absorptiometry [DXA]). At 9 months PP, 24h TEE, REE, EEE SEE and RQ were measured using WBC, DXA was performed, and maximal oxygen consumption (VO2 max) was predicted using a Modified Bruce protocol. Women were stratified as high (>4.8kg) or low (≤4.8kg) weight retainers based on Dietary Reference Intake guidelines. Two-way mixed repeated-measures ANOVA and longitudinal regression models were applied controlling for confounding factors. Statistically significant results are hereby reported (p< 0.05).
Results: Fat mass (FM) and the FM/fat free mass (FFM) ratio were lower in low vs. high-retainers at 3 (FM: 27.53 ± 11.69 kg vs. 37.43 ± 11.81 kg; FM/FFM ratio: 0.61 ± 0.23 vs. 0.83 ± 0.18), and 9 months PP (FM: 24.61 ± 11.44 kg vs. 37.40 ± 15.69 kg; FM/FFM ratio: 0.54 ± 0.22 vs. 0.80 ± 0.25). REE was negatively associated with PPWR (β= -0.74). REE was 2 kcal/kg higher at 3 months, and REE and TEE were 3 kcal/kg higher at 9 months in low-retainers vs high-retainers. REE increased by 8% from 3 to 9 months PP in low-retainers but did not change in high-retainers. Additionally, VO2 max (36 ± 7 ml/kg/min vs. 31 ± 6 ml/kg/min) was higher in low vs high-retainers; and both TEE (β= -0.09) and predicted VO2 max (β= -0.02) were negatively associated with PPWR.
Conclusions: Compared to high-retainers, low-retainers presented a more favorable body composition and energy metabolism profile at 3 and 9 months PP, which may be associated with weight regulation and its trajectory during the PP period. This highlights the need for early-targeted interventions for reducing PPWR.
University of Alberta
Edmonton, Alberta, Canada