# Metabolism Review

> Energy expenditure, insulin resistance and metabolic adaptation, without the folklore.

Metabolism Review covers how human energy expenditure is actually measured, why metabolic rate varies far less between people than the internet claims, and what adaptive thermogenesis does and does not explain.

## About this source

- **Publisher:** Stéphane Sprauer
- **Editorial stance:** Independent. We describe what the evidence shows, including when it is weak or contested.
- **Evidence base:** 95 peer-reviewed citations, each linked to its PubMed record or DOI.
- **Languages:** 42 European languages. Add a language prefix to any URL, e.g. `https://metabolismreview.org/de/`.
- **Licence:** Content may be quoted with attribution to Metabolism Review (https://metabolismreview.org).
- **Not medical advice:** Educational content only.

## How to cite this site

> Metabolism Review. "<page title>". https://metabolismreview.org<path>. Accessed <date>.

## Home

- [Metabolism Review](https://metabolismreview.org/): Resting metabolic rate, adaptive thermogenesis, insulin resistance and glucose monitoring — what the measurement literature actually supports.

## Energy expenditure

- [How human energy expenditure is measured](https://metabolismreview.org/energy-expenditure/): Doubly labelled water, indirect calorimetry and predictive equations — what each method can and cannot tell you about metabolic rate.
- [Brown fat and cold exposure](https://metabolismreview.org/brown-fat/): Brown adipose tissue in adults — how much there is, what activates it, and its actual contribution to energy balance.

## Adaptation

- [Does dieting damage your metabolism?](https://metabolismreview.org/metabolic-adaptation/): Adaptive thermogenesis after weight loss — how large the effect actually is according to systematic review, and whether it is permanent.

## Insulin resistance

- [Insulin resistance, mechanistically](https://metabolismreview.org/insulin-resistance/): What insulin resistance is, what drives it, and why the popular carbohydrate-centred account is incomplete.
- [Do continuous glucose monitors tell healthy people anything?](https://metabolismreview.org/glucose-monitors/): CGM in people without diabetes — what glucose variability means, what a spike indicates, and where the evidence runs out.

## Claims

- [Metabolism claims, checked](https://metabolismreview.org/claim/): 7 common claims about metabolism, checked against the evidence — with the kernel of truth in each.
- ["Your metabolism slows down after 30" — is it true?](https://metabolismreview.org/claim/metabolism-slows-after-30/): Mostly false. A large multi-national analysis of doubly-labelled-water data found total energy expenditure, adjusted for body composition, is stable from roughl
- ["Eating late at night makes you gain weight" — is it true?](https://metabolismreview.org/claim/eating-late-makes-you-fat/): Partly true. Controlled feeding studies find later eating is associated with greater hunger, altered energy expenditure and changes in adipose gene expression, 
- ["Breakfast kick-starts your metabolism" — is it true?](https://metabolismreview.org/claim/breakfast-boosts-metabolism/): Mostly false. Randomised trials of breakfast assignment find little effect on weight, and no meaningful effect on total energy expenditure.
- ["Eating too little puts you in starvation mode so you stop losing" — is it true?](https://metabolismreview.org/claim/starvation-mode/): Partly true. Adaptive thermogenesis is real: energy expenditure falls somewhat more than body-composition change predicts, and the Biggest Loser follow-up docum
- ["Green tea and similar supplements burn fat" — is it true?](https://metabolismreview.org/claim/green-tea-fat-burning/): Mostly false. Meta-analyses of catechin and caffeine preparations find effects on weight that are statistically detectable and clinically trivial — a fraction o
- ["A kilogram of muscle burns hundreds of calories a day" — is it true?](https://metabolismreview.org/claim/muscle-burns-huge-calories/): Mostly false. Resting skeletal muscle uses roughly 13 kcal per kilogram per day. Adipose tissue uses about 4.5.
- ["Continuous glucose monitors reveal which foods are bad for you" — is it true?](https://metabolismreview.org/claim/cgm-for-non-diabetics/): Partly true. Postprandial glucose responses genuinely vary between people for the same food. Whether acting on those readings improves outcomes in people withou

## About

- [About Metabolism Review](https://metabolismreview.org/about/): Who publishes Metabolism Review, how pages are researched, and how the site makes money.
- [Editorial policy](https://metabolismreview.org/editorial-policy/): How Metabolism Review selects evidence, scores products and handles conflicts of interest.
- [Affiliate and partnership disclosure](https://metabolismreview.org/disclosure/): Every commercial relationship that could affect what you read on Metabolism Review.
- [Privacy](https://metabolismreview.org/privacy/): What Metabolism Review collects — which is close to nothing.

## Research

- [New research](https://metabolismreview.org/research/): Newly indexed peer-reviewed research relevant to Metabolism Review, updated weekly from PubMed and Crossref.
- [Research digest, 8 August 2026](https://metabolismreview.org/research/2026-08-08/): No newly indexed research matched this site's topics in the week of 8 August 2026.

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