The Claim

Dietary protein restriction in lean men increases fasting plasma FGF21 levels by 208–361% within 5 weeks, and this increase is strongly correlated with the rise in energy intake required to maintain body weight, suggesting FGF21 is a key metabolic signal linking protein intake to energy expenditure.

Source: Dietary protein restriction elevates FGF21 levels and energy requirements to maintain body weight in lean men

What the research says

Supports is higher

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

Supports
59score
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

When lean men reduce their dietary protein intake, their blood levels of a signaling molecule called FGF21 rise significantly within five weeks, and this rise is closely tied to the increased calorie intake needed to keep their body weight stable, indicating FGF21 may play a role in connecting protein consumption to energy use.

See the scientific wording

Dietary protein restriction in lean men increases fasting plasma FGF21 levels by 208–361% within 5 weeks, and this increase is strongly correlated with the rise in energy intake required to maintain body weight, suggesting FGF21 is a key metabolic signal linking protein intake to energy expenditure.

What the research says

1 study
  1. Study: Dietary protein restriction elevates FGF21 levels and energy requirements to maintain body weight in lean men

    When men ate less protein for five weeks, their bodies made more of a hormone called FGF21, which made them need more food to keep the same weight — suggesting this hormone tells the body to burn more energy when protein is low.

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

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