Research

Energy balance

Static energy balance models (e.g., the 3500 kcal rule) significantly overestimate weight loss because they ignore adaptive thermogenesis, which causes resting energy expenditure to drop beyond what is explained by the loss of metabolically active tissue.

If you are dieting and hitting a plateau despite strict adherence to a calorie deficit, do not simply slash calories further. Your body has likely triggered adaptive thermogenesis, lowering your metabolic rate to protect fat stores. Recognize this as a biological defense mechanism, not a personal failure. Sustainable weight management may require longer adaptation periods or strategies that preserve fat-free mass, rather than aggressive restriction.

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Static modelling disregards obligatory changes in energy expenditure associated with the loss of metabolically active tissue, i.e. skeletal muscle. Additionally, it disregards the presence of adaptive thermogenesis, the underfeeding-associated fall in resting energy expenditure beyond that caused by loss of fat-free mass.
Aoife M. Egan et al. · Proceedings of The Nutrition Society · 2021

Why this rating

The paper is a comprehensive review citing multiple longitudinal studies (e.g., Minnesota Starvation Experiment, CALERIE) and meta-analyses.

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

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DOI resolved against Crossref · corpus check 2026-06-10

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