Associations of appetite sensations and metabolic characteristics with weight retention in postpartum women.

Postpartum weight retention (PPWR) is an important risk factor for long-term obesity. Appetite may be a key factor regulating PPWR. The objectives of this study were to determine the associations between (i) PPWR and appetite; and (ii) appetite, lactation, and metabolic characteristics. Data from 49 women at 9 months postpartum contributed to this cross-sectional analysis. Energy expenditure was assessed in a whole-body calorimetry unit for 24 h. Appetite sensations were rated using visual analogue scales. Lactation (min/day) was measured using a 3-day breastfeeding diary. PPWR was negatively associated with fullness (ß ± SE; R2 = -2.97 ± 0.72; 0.661; P < 0.001), and satiety (-2.75 ± 0.81; 0.617; P = 0.002), and was positively associated with hunger (2.19 ± 1.02; 0.548; P = 0.039), prospective food consumption (PFC; 2.19 ± 0.91; 0.562; P = 0.021), and composite appetite score (CAS; 0.34 ± 0.09; 0.632; P = 0.001). Lactation was associated with higher CAS (39.68 ± 15.56; 0.365; P = 0.015), hunger (3.56 ± 1.61; 0.308; P = 0.033), and PFC (4.22 ± 1.78; 0.314; P = 0.023), and with reduced sensations of fullness (-4.18 ± 1.94; 0.358; P = 0.038) and satiety (-3.83 ± 1.87; 0.295; P = 0.048). Lactation was associated with appetite, which in turn was related to PPWR. Appetite control should be explored to support postpartum weight management strategies. Novelty Postpartum weight retention was associated with appetite sensations, which were assessed throughout the day under conditions in which energy intake and expenditure were precisely matched. Lactation and other maternal metabolic factors, including carbohydrate oxidation and physical activity level may play a role in controlling appetite during the postpartum period.

The influence of energy metabolism on postpartum weight retention.

BACKGROUND: Profiling postpartum energy metabolism may assist in optimizing weight management following childbirth. OBJECTIVES: The aims of this study were to profile total energy expenditure (TEE), resting energy expenditure (REE), exercise energy expenditure, sleep energy expenditure, and respiratory quotient in women at 3 and 9 mo postpartum (3M-PP, 9M-PP, respectively), and to examine the association between energy metabolism and postpartum weight retention (PPWR). METHODS: In this cohort study, 1-h REE (measured in a whole body calorimetry unit, WBCU) and body composition (BC, measured by dual-energy X-ray absorptiometry) were measured at 3M-PP and 9M-PP (n = 49). Cardiorespiratory fitness [measured by the predicted maximal volume of oxygen consumption (p$\dot{V}$O2 max), n = 47] and 24-h TEE (WBCU, n = 43) were assessed only at 9M-PP. Women were stratified as high (>4.8 kg) or low (≤ 4.8 kg) weight retainers. Two-way mixed repeated-measures ANOVA and longitudinal regression models were applied. Linear regression was used to generate an equation at 3M-PP from the BC data, to predict the REE at 9M-PP. RESULTS: The fat mass at 3M-PP was positively associated with PPWR at 3M-PP (mean ± SE ß: 0.09 ± 0.03; P = 0.005) and 9M-PP (ß: 0.11 ± 0.04; P = 0.008), and negatively associated with REE at 3M-PP (ß: -0.16 ± 0.02; P < 0.001) and TEE at 9M-PP (ß: -0.15 ± 0.03; P < 0.001). REE was negatively associated with PPWR (ß: -0.74; 95% CI: -1.29, -0.19; P = 0.0087). REE was 2 kcal/kg higher in low- vs. high-retainers at 3M-PP, and REE and TEE were both 4 kcal/kg higher in low- vs. high-retainers at 9M-PP. Low-retainers demonstrated an increase in REE greater than expected for changes in BC. PPWR was negatively associated with TEE (ß: -0.08 ± 0.02; P = 0.0009) and p$\dot{V}$O2 max (ß: -0.02 ± 0.01; P = 0.047); p$\dot{V}$O2 max was 7 mL · kg-1 · min-1 higher in low- vs. high-retainers (P = 0.047). CONCLUSIONS: Energy metabolism, BC, and cardiorespiratory fitness may be associated with weight regulation and its trajectory during the postpartum period. This provides the foundation for future strategies to promote appropriate postpartum weight management.

The use of whole body calorimetry to compare measured versus predicted energy expenditure in postpartum women.

BACKGROUND: Accurate assessment of energy expenditure may support weight-management recommendations. Measuring energy expenditure for each postpartum woman is unfeasible; therefore, accurate predictive equations are needed. OBJECTIVES: This study compared measured with predicted resting energy expenditure (REE) and total energy expenditure (TEE) in postpartum women. METHODS: This was a longitudinal observational study. REE was measured at 3 mo postpartum (n = 52) and 9 mo postpartum (n = 49), whereas TEE was measured once at 9 mo postpartum (n = 43) by whole body calorimetry (WBC). Measured REE (REEWBC) was compared with 17 predictive equations; measured TEE plus breast milk energy output (ERWBC) was compared with the estimated energy requirements/Dietary Reference Intakes equation (EERDRI). Fat and fat-free mass were measured by dual-energy X-ray absorptiometry. Group-level agreement was assessed by the Pearson correlation, paired t test, and Bland-Altman (bias) analyses. Individual-level accuracy was assessed with the use of Bland-Altman limits of agreement, and by the percentage of women with predicted energy expenditure within 10% of measured values ("accuracy"). RESULTS: The cohort was primarily Caucasian (90%). At a group level, the best equation predicting REEWBC was the DRI at 3 mo postpartum (-7 kcal, -0.1%; absolute and percentage bias, respectively), and the Harris-Benedict at 9 mo postpartum (-17 kcal, -0.5%). At an individual level, the Food and Agriculture Organization/World Health Organization/United Nations University (FAO/WHO/UNU) height and weight equation was the most accurate at 3 mo postpartum (100% accuracy) and 9 mo postpartum (98% accuracy), with the smallest limits of agreement. Equations including body composition variables were not more accurate. Compared with ERWBC, EERDRI bias was -36 kcal, with inaccurate predictions in 33% of women. CONCLUSIONS: Many REE predictive equations were accurate for group assessment, with the FAO/WHO/UNU height and weight equation having the highest accuracy for individuals. EERDRI performed well at a group level, but inaccurately for 33% of women. A greater understanding of the physiology driving energy expenditure in the postpartum period is needed to better predict TEE and ultimately guide effective weight-management recommendations.

Trajectory and determinants of change in lean soft tissue over the postpartum period.

The aim of this study was to characterise changes in lean soft tissue (LST) and examine the contributions of energy intake, physical activity and breast-feeding practices to LST changes at 3 and 9 months postpartum. We examined current weight, LST (via dual-energy X-ray absorptiometry), dietary intake (3-d food diary), physical activity (Baecke questionnaire) and breast-feeding practices (3-d breast-feeding diary) in forty-nine women aged 32·9 (sd 3·8) years. Changes in LST varied from -2·51 to +2·50 kg with twenty-nine women gaining LST (1·1 (sd 0·7) kg, P<0·001) and twenty women losing LST (-0·9 (sd 0·8) kg, P<0·001). Energy intake (133 (SD 42) v. 109 (SD 33) kJ/kg, P=0·019) and % kJ from fat at 3 months postpartum was higher in women who gained LST at 9 months postpartum (gained LST=34 (sd 5) % kJ; lost LST=29 (sd 4) % kJ, P=0·002). Women who gained LST reported breast-feeding their infants more frequently (gained LST=8 (sd 3) feeds/d; lost LST=5 (sd 1) feeds/d, P=0·014) and for more time per d (gained LST=115 (sd 78) min/d; lost LST=59 (sd 34) min/d, P=0·016) at 9 months postpartum. Energy intake and % kJ from fat at 3 months were significant predictors of LST gain (ß=0·08 (se 0·04) and 0·24 (se 0·09), respectively). This suggests that gain in LST may be associated with more frequent and longer episodes of breast-feeding at 9 months postpartum as well as dietary intake early in the postpartum period.

Changes in Energy Metabolism from Prepregnancy to Postpartum: A Case Report.

PURPOSE: Energy metabolism is at the core of maintaining healthy body weights. Likewise, the assessment of energy needs is essential for providing adequate dietary advice. We explored differences in energy metabolism of a primigravid woman (age: 30 years) at 1 month prepregnancy ("baseline"), during pregnancy (33 weeks), and at 3 and 9 months postpartum. Measured versus estimated energy expenditure were compared using equations commonly used in clinical practice. METHODS: Energy metabolism was measured using a state-of-the-art whole body calorimetry unit (WBCU). Body composition (dual-energy X-ray absorptiometry), energy intake (3-day food records), physical activity (Baecke questionnaire), and breastmilk volume/breastfeeding energy expenditure (24-hours of infant test-retest weighing) were assessed. RESULTS: This case report is the first to assess energy expenditure in 3 different stages of a woman's life (prepregnancy, pregnancy, and postpartum) using WBCU. We noticed that weight and energy needs returned to prepregnancy values at 9 months postpartum, although a pattern of altered body composition emerged (higher fat/lean ratio) without changes in physical activity and energy intake. For this woman, current recommendations for energy overestimated actual needs by 350 kcal/day (9 months postpartum). CONCLUSION: It is likely that more accurate approaches are needed to estimate energy needs during and postpregnancy, with targeted interventions to optimize body composition.