Metabolic adaptation is associated with less weight and fat mass loss in response to low-energy diets

Abstract

Background The practical relevance of metabolic adaptation remains a controversial issue. To the best of our knowledge, no study has properly evaluated the role of metabolic adaptation in modulating weight loss outcomes. Therefore, the aim of this study was to determine the association between metabolic adaptation, at the level of resting metabolic rate (RMR), and weight and fat mass (FM) loss after low-energy diets (LED), after adjusting for dietary adherence and other confounders. Methods 71 individuals with obesity (BMI: 34.6 ± 3.4 kg/m2; age: 45.4 ± 8.2 years; 33 males) were randomized to one of three 1000 kcal/day diets for 8 weeks. Body weight, FM and fat-free mass (FFM) (air displacement plethysmography), RMR (indirect calorimetry) and physical activity level (PAL) (armbands) were measured at baseline and at week 9. Metabolic adaptation at week 9 was defined as measured RMR minus predicted RMR at week 9. An equation to predict RMR was derived from baseline data of all participants that were part of this analysis and included age, sex, FM and FFM as predictors. Dietary adherence was calculated from RMR, PAL and body composition changes. Linear regression was used to assess the potential role of metabolic adaptation in predicting weight and FM loss after adjusting for dietary adherence, average PAL, sex, baseline FM and FFM and randomization group. Results Participants lost on average 14 ± 4 kg of body weight (13 ± 3%) and presented with metabolic adaptation (−92 ± 110 kcal/day, P < 0.001). Metabolic adaptation was a significant predictor of both weight (β = −0.009, P < 0.001) and FM loss (β = −0.008, P < 0.001), even after adjusting for confounders (R2 = 0.88, 0.93, respectively, P < 0.001 for both). On average, an increase in metabolic adaptation of 50 kcal/day was associated with a 0.5 kg lower weight and FM loss in response to the LED. Conclusion In individuals with obesity, metabolic adaptation at the level of RMR is associated with less weight and FM loss in response to LED. Trial registration ID: NCT02944253.

Metabolic adaptation delays time to reach weight loss goals

“…The present findings are in line with recent data from our group showing that metabolic adaptation at the level of RMR was associated with less weight and FM loss following low‐energy diets in individuals with obesity (21). Moreover, Goele and colleagues (31) reported that in women who experienced metabolic adaptation after a low‐energy diet, 38% of the difference between measured and predicted weight loss was due to metabolic adaptation at the level of RMR.…”

“…We have confirmed these findings in two recent studies (19,20) by showing that metabolic adaptation at the level of RMR, after weight loss, was not associated with weight regain up to 2 years of follow‐up. Moreover, in another recently published manuscript, our research group showed that metabolic adaptation at the level of RMR was associated with less weight and fat mass (FM) loss in response to a low‐energy diet, in men and women with obesity (21). However, it remains to be investigated whether metabolic adaptation contributes to resistance to weight loss by increasing the time necessary to achieve weight loss goals.…”

“…uscript, our research group showed that metabolic adaptation at the level of RMR was associated with less weight and fat mass (FM) loss in response to a low-energy diet, in men and women with obesity (21). However, it remains to be investigated whether metabolic adaptation contributes to resistance to weight loss by increasing the time necessary to achieve weight loss goals.…”

Soluble Receptor for Advanced Glycation End Products (sRAGE) Isoforms Predict Changes in Resting Energy Expenditure in Adults with Obesity during Weight Loss

“…Compensatory responses in REE during negative energy balance that are independent of changes in FM and FFM (i.e., AT) may attenuate weight loss ( 4 , 28 , 29 ). Therefore, identifying predictors of metabolic adaptation may contribute to better treatment of obesity and weight management ( 30 ).…”

“…An observed response to caloric restriction and weight loss is adaptive thermogenesis (AT), which is a reduction in energy expenditure related to improved cellular energy efficiency that is independent of changes in fat mass (FM) and fat-free mass (FFM). AT persists in the weight-reduced state ( 3 ) and during the dynamic process of negative energy balance, and may limit the ability to effectively maintain weight loss ( 4 ).…”