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Evaluation of Energy Metabolism, Weight Retention and Appetite in Postpartum Women
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- Author / Creator
- Radin Pereira, Leticia C
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Postpartum weight retention (PPWR) is an important risk factor for long-term obesity. Accurate assessment and understanding of energy expenditure and other metabolic characteristics of postpartum women may improve weight management following childbirth. The overall aims of this research were to investigate the energy metabolism profile of postpartum women; and to explore key metabolic characteristics associated with weight retention during this life stage. Additionally, the validity of resting energy expenditure (REE) predictive equations was explored, as well as the accuracy of current recommendations in predicting total energy expenditure (TEE).
This was a longitudinal observational study involving women at three (3M-PP; n=52) and nine months postpartum (9M-PP; n=49); some measurements were only undertaken at 9M-PP. Women were stratified as high (>4.8 kg) or low (≤4.8 kg) weight retainers. Energy expenditure and macronutrient oxidation were measured by whole body calorimetry (WBC). Body composition was determined using dual-energy X-ray absorptiometry. Appetite sensations (i.e. hunger, prospective food consumption [PFC], fullness, satiety) were assessed using visual analogue scales, the results of which were then used to calculate a composite appetite score (CAS). Lactation pattern was measured using a 3-day breastfeeding diary including a 24-h infant test weighing protocol. Cardiorespiratory fitness was determined through a fitness test measuring the predicted maximal volume of oxygen consumption (pV̇O2 max). REE was compared to 17 commonly used predictive equations; measured TEE was compared to the Estimated Energy Requirements/DRI equation (EERDRI).
This research showed that REE, TEE, and pV̇O2 max were lower in high-retainers than low-retainers. REE at 3M-PP was negatively associated with PPWR at 3M-PP (mean β ± SE: -0.570 ± 0.196, P=0.004) and 9M-PP (-0.688 ± 0.252, P=0.006). An increase in REE from early to late postpartum was observed in low-retainers, which was greater than predicted by changes in body composition. This was not observed in high-retainers. Daily duration of lactation episodes was associated with higher CAS (39.68 ± 15.56, P=0.015), hunger (3.56 ± 1.61, P=0.033), and PFC (4.22 ± 1.78, P=0.023), and with reduced sensations of fullness (-4.18 ± 1.94, P=0.038) and satiety (-3.83 ± 1.87, P=0.048). Women’s perceptions of appetite were associated with PPWR (fullness: -2.97 ± 0.72, P<0.001; satiety: -2.75 ± 0.81, P=0.002; hunger: 2.19 ± 1.02, P=0.039, PFC: 2.19± 0.91, P=0.021, and CAS: 0.34 ± 0.09, P=0.001). Daily carbohydrate oxidation and physical activity level were also associated with appetite sensations. Several REE predictive equations performed well at a group level at both time points. At an individual level, high rates of inaccuracy and wide limits of agreement were observed. Compared to TEE, EERDRI yielded inaccurate results for 33% of women, however accounting for individual lactation patterns improved accuracy.
In conclusion, lactation pattern, carbohydrate oxidation, and physical activity level were associated with appetite sensations. Along with appetite, energy expenditure and cardiorespiratory fitness were associated with body weight regulation. Additionally, commonly used predictive equations did not accurately estimate energy expenditure at an individual level. Collectively, these findings have the potential to contribute to 1) the development of future weight management strategies in postpartum women by targeting appetite and energy metabolism; and 2) the formation of energy recommendations tailored to the needs of individual postpartum women. These may also assist in promoting appropriate body weight and improving care during this life stage. -
- Graduation date
- Fall 2019
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- Type of Item
- Thesis
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- Degree
- Doctor of Philosophy
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- License
- Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.