Does the weight loss efficacy of alternate day fasting differ according to sex and menopausal status?

Nutr Metab Cardiovasc Dis. 2021 Feb 8;31(2):641-649. doi: 10.1016/j.numecd.2020.10.018. Epub 2020 Oct 31.


Background and aims: This study examined if the weight loss and metabolic benefits of alternate day fasting (ADF) varies according to sex and menopausal status in adults with obesity.

Methods and results: This secondary analysis pooled the data of men and women (n = 75) who participated in three 12-week ADF studies (500 kcal fast day; alternated with an ad libitum intake feast day). Body weight decreased in premenopausal women (-4.6 ± 3.2%), postmenopausal women (-6.5 ± 3.2%) and men (-6.2 ± 4.4%) (main effect of time, P < 0.001), with no difference between groups (no group × time interaction). Energy intake on fast days was higher than prescribed in all groups (∼400-500 excess kcal consumed), with no differences between groups. Fat mass, lean mass, fasting insulin, and insulin resistance, and blood pressure decreased similarly in all groups (main effect of time, P < 0.05 for all comparisons). LDL cholesterol decreased more in postmenopausal versus premenopausal women (group × time interaction, P = 0.01). Fasting glucose, HDL cholesterol, and triglycerides remained unchanged in all groups.

Conclusion: These findings suggest that the weight loss and metabolic benefits of ADF do not generally vary according to sex or menopausal status in adults with obesity.

Trial registration:, NCT00960505; NCT03528317.

Keywords: Intermittent fasting; Menopausal status; Metabolic disease; Obesity; Sex differences; Weight loss.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Caloric Restriction*
  • Clinical Trials as Topic
  • Fasting*
  • Female
  • Humans
  • Male
  • Menopause*
  • Middle Aged
  • Obesity / diagnosis
  • Obesity / diet therapy*
  • Obesity / physiopathology
  • Postmenopause
  • Premenopause
  • Sex Factors
  • Time Factors
  • Treatment Outcome
  • Weight Loss*

Associated data