The Claim

In C57BL/6 mice, the decline in basal metabolic rate during calorie restriction is proportional to the severity of the restriction and is fully accounted for by reductions in liver, spleen, pancreas, tail, and brown adipose tissue mass, while protein restriction at equivalent caloric levels does not reduce basal metabolic rate.

Source: The effects of graded levels of calorie restriction: VIII. Impact of short term calorie and protein restriction on basal metabolic rate in the C57BL/6 mouse

What the research says

Supports is higher

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

Supports
17score
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.

How it works
1 study reviewed
In plain English

In C57BL/6 mice, reducing calorie intake lowers basal metabolic rate in proportion to how much food is cut, and this drop is entirely explained by the loss of mass in the liver, spleen, pancreas, tail, and brown fat; however, reducing protein intake without changing total calories does not lower basal metabolic rate.

See the scientific wording

In C57BL/6 mice, the basal metabolic rate decline during calorie restriction is proportional to the severity of restriction and is fully accounted for by reductions in liver, spleen, pancreas, tail, and brown adipose tissue mass, whereas protein restriction at equivalent caloric levels does not reduce BMR.

Why this might work

When less food is eaten, the liver, spleen, pancreas, tail, and brown fat shrink in size, and because these organs use a lot of energy, the body burns fewer calories at rest. When the same number of calories come from food with less protein, these organs do not shrink, so the body keeps burning the same amount of energy.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: The effects of graded levels of calorie restriction: VIII. Impact of short term calorie and protein restriction on basal metabolic rate in the C57BL/6 mouse

    When mice eat less food, their metabolism slows down because organs like the liver and spleen get smaller — and that’s all that’s happening, not some hidden slowdown in cells. But the study didn’t test what happens when mice eat the same calories but less protein.

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

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

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