Research

Hormonal

Adaptive thermogenesis (AT) is primarily mediated by hormonal signals (leptin and insulin) that downregulate substrate cycling in skeletal muscle, reducing energy expenditure to preserve fat stores.

Understanding that hormones like leptin and insulin drive metabolic slowdown helps explain why weight loss stalls. This is not just 'willpower'; it is a hormonal defense of fat stores. Strategies that maintain muscle mass and avoid extreme deficits may mitigate the severity of this hormonal suppression.

GoodSupportsHIGH confidence
During periods of energy restriction, depleted TAG stores result in reduced leptin production, which directly downregulates substrate cycling in the skeletal muscle. Additionally, leptin indirectly downregulates skeletal muscle thermogenesis through suppression of sympathetic-thyroid axis...
Aoife M. Egan et al. · Proceedings of The Nutrition Society · 2021

Why this rating

Supported by specific mechanistic studies cited (e.g., Leibel et al., reference 131).

Source

Dynamic changes in energy expenditure in response to underfeeding: a review

Aoife M. Egan et al. · Proceedings of The Nutrition Society · 2021

DOI 10.1017/s0029665121003669

narrative_reviewCited 12×
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DOI resolved against Crossref · corpus check 2026-06-10

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