Research

Hormonal

In humans with extreme BMI (obesity or anorexia), circulating irisin levels are primarily determined by fat mass rather than daily physical activity or resting energy expenditure.

If you have obesity, your body is already producing high levels of irisin, likely as a response to the high fat mass. This does not mean exercise is useless, but it suggests that simply exercising more may not linearly increase irisin or metabolic benefits in the same way it might in lean individuals. The hormonal environment is already saturated by the presence of adipose tissue.

GoodQualifiesHIGH confidence
Fat mass was revealed as the main factor explaining approximately 30% of the variability in the irisin plasma levels independently of age, fat free mass, daily physical activity, REE, and BMI group.
María Pardo et al. · International Journal of Endocrinology · 2014

Why this rating

Large sample size (n=145), multi-center design, and robust multivariate regression analysis controlling for confounders.

Source

Association of Irisin with Fat Mass, Resting Energy Expenditure, and Daily Activity in Conditions of Extreme Body Mass Index

María Pardo et al. · International Journal of Endocrinology · 2014

DOI 10.1155/2014/857270

cross_sectional · n=145Cited 213×
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DOI resolved against Crossref · corpus check 2026-06-10

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