Elsevier

Clinical Nutrition

Volume 37, Issue 1, February 2018, Pages 250-253
Clinical Nutrition

Original article
Reduction in energy expenditure during weight loss is higher than predicted based on fat free mass and fat mass in older adults

https://doi.org/10.1016/j.clnu.2016.12.014Get rights and content

Summary

Background & aim

The aim of this study was to describe a decrease in resting energy expenditure during weight loss that is larger than expected based on changes in body composition, called adaptive thermogenesis (AT), in overweight and obese older adults.

Methods

Multiple studies were combined to assess AT in younger and older subjects. Body composition and resting energy expenditure (REE) were measured before and after weight loss. Baseline values were used to predict fat free mass and fat mass adjusted REE after weight loss. AT was defined as the difference between predicted and measured REE after weight loss. The median age of 55 y was used as a cutoff to compare older with younger subjects. The relation between AT and age was investigated using linear regression analysis.

Results

In this study 254 (M = 88, F = 166) overweight and obese subjects were included (BMI: 31.7 ± 4.4 kg/m2, age: 51 ± 14 y). The AT was only significant for older subjects (64 ± 185 kcal/d, 95% CI [32, 96]), but not for younger subjects (19 ± 152 kcal/d, 95% CI [−9, 46]). The size of the AT was significantly higher for older compared to younger adults (β = 47, p = 0.048), independent of gender and type and duration of the weight loss program.

Conclusions

We conclude that adaptive thermogenesis is present only in older subjects, which might have implications for weight management in older adults. A reduced energy intake is advised to counteract the adaptive thermogenesis.

Introduction

Adaptive thermogenesis is defined as the decrease in resting energy expenditure (REE) greater than expected based on changes in fat free mass and fat mass [1]. Because the REE contributes for approximately 70% of the total daily energy expenditure [2], adaptive thermogenesis can have substantial impact on daily energy expenditure. As a result it might be more difficult to preserve energy balance to maintain weight, or to create an energy deficit to lose weight.

Adaptive thermogenesis has been described in different weight loss studies [3], [4], [5]. It has been stated that the discussion is no longer about the existence of the phenomenon of adaptive thermogenesis, but about its magnitude and practical implication [6].

In addition to the ongoing discussion on the magnitude and practical implication of adaptive thermogenesis, it has been pointed out that the relation between age and adaptive thermogenesis is unclear [7], [8]. Since the prevalence of overweight and obesity is increasing as well as aging, the number of older adults with overweight and obesity increases [9]. We have been interested in providing adequate interventions for obese older adults that result in healthy weight loss, i.e. loss of fat mass with muscle mass preservation [10]. Because adaptive thermogenesis might have an unfavorable effect on the energy balance, it potentially reduces the success of weight loss interventions and weight maintenance in older adults. Therefore, the aim of this study was to describe adaptive thermogenesis in overweight and obese older adults during weight loss. For this purpose, we accumulated data over a larger age range, which made it possible to compare older with younger overweight individuals.

Section snippets

Subjects

The data from 9 different weight loss studies were combined for this investigation, e.g. [10]. The studies were conducted at the Amsterdam Nutritional Assessment Center (ANAC) of the Amsterdam University of Applied Sciences between 2006 and 2014. Subjects were overweight or obese (body mass index (BMI) > 25 kg/m2) but otherwise healthy. Written informed consent was obtained from all subjects.

Design

All subjects followed a hypocaloric diet. In addition, in some studies a subgroup of participants

Subjects

In total, 254 subjects were included in this study (M = 88, F = 166). Baseline characteristics of the younger and older subjects are displayed in Table 1. On average, older subjects had a significant higher fat mass than younger subjects (39.7 ± 10.0 vs. 36.3 ± 10.0 kg, p < 0.01) and a lower REE (1755 ± 295 kcal/d vs. 1840 ± 340 kcal/d, p = 0.04).

On average body weight in older subjects declined by −3.2 ± 3.0 kg (−3.4 ± 3.3 kg fat mass; +0.1 ± 1.8 kg fat free mass) and in younger subjects

Discussion

This study shows that adaptive thermogenesis could be quite significant in overweight and obese older adults during weight loss. Adaptive thermogenesis may have consequences for ongoing weight loss and weight maintenance in older adults.

Conclusion

We conclude that adaptive thermogenesis is present in older subjects, while it was not observed in younger subjects in this study. The adaptive thermogenesis in older subjects might have implications for weight loss and weight maintenance. Nutritionists and dietitians need to be aware of the role of adaptive thermogenesis in weight loss and weight maintenance, especially in older subjects. If necessary a reduced energy intake should be advised to counteract the adaptive thermogenesis.

Statement of authorship

Conception and design of the study: TH, PW. Acquisition of data: AV. Analysis and interpretation of data: TH, RM, MT, PW. Writing the manuscript: TH, AV, RM, MT, PW.

Conflict of interest

The authors declare that there is no conflict of interests. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

References (26)

  • M.J. Müller et al.

    Adaptive thermogenesis with weight loss in humans

    Obesity

    (2013)
  • M.-M.G. Wilson et al.

    Invited review: aging and energy balance

    J Appl Physiol

    (2003)
  • T.S. Han et al.

    Obesity and weight management in the elderly

    Br Med Bull

    (2011)
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