Research

Hormonal

Alternate day fasting (36-hour fasts on alternating days for 3 weeks) impairs glucose tolerance in nonobese women while improving insulin sensitivity in nonobese men.

If you are a nonobese woman considering alternate day fasting, monitor your blood sugar response to meals, as this protocol may worsen glucose tolerance. Men may experience improved insulin sensitivity under the same conditions. The lack of control over feasting day calories may also mask true metabolic adaptations.

ModerateQualifiesMEDIUM confidence
Glucose response to a meal was slightly impaired in women after 3 weeks of treatment (p < 0.01)... men had no change in glucose response and a significant reduction in insulin response (p < 0.03).
Leonie K. Heilbronn et al. · Obesity Research · 2005

Why this rating

Small sample size (n=16), short duration (3 weeks), and lack of gold-standard clamp measurements limit generalizability.

Source

Glucose Tolerance and Skeletal Muscle Gene Expression in Response to Alternate Day Fasting

Leonie K. Heilbronn et al. · Obesity Research · 2005

DOI 10.1038/oby.2005.61

crossover · n=16Cited 174×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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