The Claim
A ketogenic diet increases circulating fibroblast growth factor 21 (FGF21) levels in male mice but not in female mice, and this increase is correlated with elevated FGF21 expression in brown adipose tissue.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
In male mice, a ketogenic diet raises levels of the protein FGF21 in the blood, and this increase is linked to higher FGF21 activity in brown fat tissue. In female mice, the same diet does not raise FGF21 levels.
See the scientific wording
Ketogenic diet increases circulating fibroblast growth factor 21 (FGF21) levels in male mice but not in female mice, and this increase correlates with elevated FGF21 expression in brown adipose tissue, suggesting a sex-specific role for FGF21 in mediating metabolic adaptation.
In males, a high-fat, low-carb diet triggers brown fat to produce more FGF21, which increases energy burning and fat loss. In females, estrogen blocks this FGF21 increase, so brown fat doesn't activate, leading to fat gain instead. Removing estrogen in females allows FGF21 to rise and fat loss to occur, while removing testosterone in males stops the effect.
What the research says
1 studyStudy: Sex Differences in Ketogenic Diet Response Reveal Gonadal Hormone Interaction With FGF21 in Mice
In mice, eating a keto diet makes male mice produce more of a hormone called FGF21 in their brown fat, helping them lose weight, but female mice don’t make more of it and instead gain weight. The study shows this difference is linked to sex hormones.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.