Research

Hormonal

Long-term severe calorie restriction (1-6 years) does not reduce serum IGF-1 or IGF-1:IGFBP-3 ratio in healthy humans, unlike the reduction observed in rodents.

If you are practicing long-term calorie restriction for health or longevity, do not expect your IGF-1 levels to drop significantly, even if you lose weight. This differs from what is seen in mice. Your body maintains IGF-1 levels despite the energy deficit, provided you are not malnourished.

GoodRefutesHIGH confidence
These findings demonstrate that, unlike in rodents, long-term severe CR does not reduce serum IGF-1 concentration and IGF-1 : IGFBP-3 ratio in humans.
Luigi Fontana et al. · Aging Cell · 2008

Why this rating

Randomized controlled trial (1 year) and cross-sectional study (6 years) with adequate sample sizes and controls.

Source

Long‐term effects of calorie or protein restriction on serum IGF‐1 and IGFBP‐3 concentration in humans

Luigi Fontana et al. · Aging Cell · 2008

DOI 10.1111/j.1474-9726.2008.00417.x

rct · n=94Cited 391×
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DOI resolved against Crossref · corpus check 2026-06-10

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