Brown adipose tissue does not seem to mediate metabolic adaptation to overfeeding in men

Abstract

Objective Brown adipose tissue (BAT) generates heat in response to cold, and low BAT activity has been linked to obesity. However, recent studies are inconclusive as to whether BAT is involved in diet-induced thermogenesis and mitigates weight gain from prolonged overeating. We therefore investigated whether BAT activity is related to metabolic adaptation arising from 8 weeks of overfeeding in humans. Methods Fourteen men (aged 24±3 years, BMI 24.5±1.6 kg/m2) were overfed by 40% for 8 weeks. Before and after, energy expenditure and metabolic adaptation were measured by whole-room respiratory calorimetry. A marker of BAT activity was measured using infrared imaging of the supraclavicular BAT depot. Results At the end of 8 weeks of overfeeding, metabolic adaptation—defined as the percent increase in sleeping energy expenditure beyond that expected from weight gain—rose from −0.9 ± 3.9% to 4.7±5.6% (p=0.001). However, BAT thermal activity was unchanged (p=0.81). Moreover, BAT thermal activity did not correlate with the degree of metabolic adaptation (p=0.32), nor with the change in body weight (p=0.51). Conclusions BAT thermal activity does not change in response to overfeeding, nor does it correlate with adaptive thermogenesis. Our data suggest that BAT does not mediate metabolic adaptation to overeating in humans.

Brown Adipose Tissue: an Update on Recent Findings

“…However, recent data in humans indicate that unlike CIT, DIT is probably not mediated by BAT [26]. Additionally, we recently reported that BAT probably does not mediate the metabolic adaptation following 8 weeks of overfeeding in men [27]. Together, these studies do not support a role of BAT in modulating DIT and do not lend support to an important role for BAT in the regulation of human body weight as previously suggested by Kozak [28].…”

Infrared Thermography for Estimating Supraclavicular Skin Temperature and BAT Activity in Humans: A Systematic Review

“…The first study to use IRT to estimate SST was performed in 2011 . Ten studies were then published between 2011 and 2016 , six in 2017 , six in 2018 , and one until April 2019 .…”

“…Most, but not all, of the identified studies ( n = 18; 75%) included cooling protocols, although the duration, temperature, and the way of inducing cooling differed between studies (Figure ). Nine out of these eighteen studies used hands/feet immersion in cold water (temperature 10.8°C ± 8.7°C, duration: 6.1 ± 6.8 minutes) . Seven of these nine studies used a cold exposure of < 5 minutes.…”

“…The first study to use IRT to estimate SST was performed in 2011 (24). Ten studies were then published between 2011 and 2016 (25)(26)(27)(28)(29)(30)(31)(32)(33)(34), six in 2017 (35)(36)(37)(38)(39)(40), six in 2018 (16,(41)(42)(43)(44), and one until April 2019 (45).…”

Human brown adipose tissue as a target for obesity management; beyond cold‐induced thermogenesis

“…The first study dedicated to determination of a contribution of BAT to adaptive DIT was published recently by Peterson et al . . In their study involving 8 weeks overfeeding by 40% of weight maintenance energy intake in healthy males, sleeping energy expenditure was increased by 4.7% above that expected based on the amount of weight gained.…”