Research

Energy balance

Prolonged energy restriction induces adaptive thermogenesis, causing resting energy expenditure (REE) to fall significantly more than predicted by changes in body composition alone, thereby creating an energetic efficiency that hinders weight loss.

When you diet, your body doesn't just burn less energy because you are smaller; it actively becomes more efficient, burning even less than expected for your new size. This 'adaptive thermogenesis' is strongest during the active weight loss phase. If you hit a plateau, it may be because your body has adapted to the deficit. Recognizing this biological defense mechanism can help you adjust your strategy (e.g., slight diet breaks or resistance training) rather than assuming you are failing.

GoodSupportsHIGH confidence
In such cases a greater energetic efficiency, i.e. an adaptive component of thermogenesis, often appears... the reduction in REE might not always be proportional to the decrease in body substance.
Éric Doucet et al. · British Journal Of Nutrition · 2001

Why this rating

Randomized controlled trial with objective indirect calorimetry measurements over 15 weeks, though the drug arm (fenfluramine) was not the primary focus of the adaptive thermogenesis claim.

Source

Evidence for the existence of adaptive thermogenesis during weight loss

Éric Doucet et al. · British Journal Of Nutrition · 2001

DOI 10.1079/bjn2001348

rct · n=35Cited 157×
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DOI resolved against Crossref · corpus check 2026-06-10

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