Narrative review: FGF21, early-life growth and nutrition
This narrative review examines the hormone FGF21, its nutritional regulation and its possible role in metabolic development and growth in early life; it proposes FGF21 as a possible mechanism behind the early protein hypothesis. [1]
Automatic summary · not editorially reviewed
The key findings
FGF21 is described as a hormone produced mainly in the liver that helps regulate metabolism throughout the body. [1]
In rodents, FGF21 treatment protected against diet-induced obesity, and overexpression could even extend lifespan. [1]
In human infants, linear growth was negatively correlated with circulating FGF21 concentrations. [1]
The source at a glance
- Study type / format
- Narrative review (abstract only)
- Population / context
- Human infants, mice and rodents as described in the review abstract
- Summary based on
- Study abstract
- Original publication
- August 8, 2026
FGF21 from liver and its metabolic actions
The review describes FGF21 as a hormone produced mainly in the liver that helps regulate metabolism throughout the body. Its described functions include promoting glucose uptake in fat cells, enhancing fat oxidation and inducing thermogenesis. In rodents, treatment with FGF21 protected against diet-induced obesity, and overexpression could even extend lifespan. These are rodent findings, not evidence of human lifespan benefits.
Supporting source [1]
Diet, FGF21 and macronutrient preference in rodents
The relationship between FGF21 and dietary macronutrients is described as complex and bidirectional. Diets low in protein and high in carbohydrates, especially simple sugars, strongly stimulate FGF21 production. Rodent experiments indicate that, once secreted, FGF21 acts on the brain, stimulating protein intake and suppressing preference for sugars.
Supporting source [1]
Early-life growth, breast milk and the proposed hypothesis
Compared with adults, the role of FGF21 in metabolic physiology and programming during early life is less well understood. In human infants, linear growth was negatively correlated with circulating FGF21 concentrations. In mice, lipids in breast milk stimulate FGF21 production after birth, possibly activating thermogenesis. The authors hypothesize that FGF21-mediated regulation could provide a mechanistic basis for the early protein hypothesis, which posits that higher protein intake in infancy exacerbates weight gain and raises later cardiometabolic disease risk.
Supporting source [1]
How to interpret this
This is an abstract of a narrative review; the full text was not reviewed. The abstract reports no study design details, sample sizes or follow-up. Rodent and infant findings are described as associations or experiments, not as established causes or human lifespan benefits. The early protein hypothesis is presented as the authors' hypothesis.
Based on the study abstract; the full paper, tables and supplementary data were not reviewed.
Source & supporting passages
Wali JA, Ramos-Nieves JM, Binia A, van der Beek EM. · europepmc.org · August 8, 2026