Research

Hormonal

An acute increase in fibroblast growth factor 21 (FGF21) in response to low-protein overfeeding serves as a biomarker identifying individuals with a 'thrifty' metabolism who are susceptible to weight gain.

If you struggle with weight gain despite similar efforts to others, your body's hormonal response (specifically FGF21) to certain dietary stresses might be the cause. This isn't about willpower; it's a physiological 'thrifty' phenotype. Future testing may allow you to identify this susceptibility early, shifting focus from generic advice to targeted prevention.

ModerateSupportsMEDIUM confidence
the authors observe that ingestion of a low-protein diet (3% of total intake) that provides twice the amount of energy required for weight maintenance causes almost an average threefold increase in FGF21... individuals who failed to significantly increase FGF21 in response to acute overfeeding with low protein gain the most weight during the follow-up.
Leanne M. Redman et al. · Diabetes · 2019

Why this rating

Based on a single study with a small sample size and limitations acknowledged by the authors.

Source

In Pursuit of a Biomarker of Weight Gain Susceptibility—Is FGF21 a Candidate?

Leanne M. Redman et al. · Diabetes · 2019

DOI 10.2337/dbi18-0038

narrative_reviewCited 6×
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DOI resolved against Crossref · corpus check 2026-06-10

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