The Claim

The combined mass of metabolically active organs—including the liver, heart, kidneys, and brain—contributes significantly to resting energy expenditure in healthy adults, with the liver and heart exhibiting the highest tissue-specific metabolic rates per kilogram.

Source: Effect of caloric restriction on organ size and its contribution to metabolic adaptation: an ancillary analysis of CALERIE 2

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
69score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Description
1 study reviewed
In plain English

Even when you're sitting still, your liver and heart are burning a lot of energy—more than other organs—so the bigger these organs are, the more calories your body uses just to keep them running.

See the scientific wording

The mass of metabolically active organs (liver, heart, kidneys, brain) contributes significantly to resting energy expenditure, with liver and heart having the highest tissue-specific metabolic rates per kilogram in healthy adults.

Why this might work

The liver and heart use the most energy per gram just to stay alive, so when they are larger, the body burns more calories at rest. When these organs shrink, the body burns fewer calories. The brain and kidneys also use a lot of energy, but their size stays stable even when the body loses weight, so they don't change the total energy burn as much. The total energy used at rest depends on how much of these high-demand organs are present.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Effect of caloric restriction on organ size and its contribution to metabolic adaptation: an ancillary analysis of CALERIE 2

    When people ate less for two years, their liver and heart got smaller, and their body burned fewer calories than expected — but their brain and kidneys stayed the same size. This suggests that liver and heart use a lot of energy just to keep working, even when you're resting.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.