Fasting Evidence

Evidence map

Intermittent fasting: what the evidence base looks like

13 publications, 3 of them trials and 7 syntheses. This page describes the shape of that literature rather than summarising its conclusions.

Updated 4 min read 13 citations

What the evidence on intermittent fasting is made of Of 13 publications on this topic, the breakdown by study type: 7 meta-analysis, 3 randomised trial, 3 review. 733meta-analysis (7)randomised trial (3)review (3)
13 publications, by study type. Volume is not strength — the same count can be a settled question or a pile of commentary, and which one it is depends almost entirely on this breakdown. Harvested from PubMed and Crossref; publication type as recorded by the source.

What this literature is made of

The synthesis is ahead of the primary literature here — reviews and meta-analyses drawing on a modest number of underlying studies. Treat confident conclusions with the caution the sample size deserves.

The distinction that matters most is between synthesis and primary research. A meta-analysis pools trials and is the closest thing to a settled answer a field produces. A narrative review is one group's reading of the same material and can be selective without being dishonest. Counting them together, which most citation counts do, obscures exactly the thing you want to know.

When the intermittent fasting literature was published Publication years for the 13 papers on this topic, grouped into bands from before 2015 through to 2023 onwards. 2023 onwards9 papers2020-20224 papers
Still active. The most recent paper here is from 2025, so this is a field where an answer written today may not hold for long. Publication years as recorded by PubMed and Crossref.

How this page is built

Everything above is computed from the citations this site harvested from PubMed and Crossref, not written by hand. When the weekly harvest finds a new paper on this topic, these counts change and the characterisation changes with them. That is the point: a hand-written claim about how strong an evidence base is starts decaying the day it is written.

Publication type is taken as the source records it. That is imperfect — journals label inconsistently, and a paper indexed as a "review" may be a systematic one — so treat the bands as approximate. They are accurate enough to distinguish a trial literature from a commentary literature, which is the distinction that matters.

The strongest work on this topic

Ordered by study design first, then recency. The full set is listed in the references below.

  1. Intermittent fasting strategies and their effects on body weight and other cardiometabolic risk factors: systematic review and network meta-analysis of randomised clinical trials — Semnani-Azad Z, Khan TA, Chiavaroli L et al., 2025, meta-analysis
  2. Longer-term effects of intermittent fasting on body composition and cardiometabolic health in adults with overweight and obesity: A systematic review and meta-analysis — Khalafi M, Maleki AH, Ehsanifar M et al., 2025, meta-analysis
  3. Intermittent Fasting: Does It Affect Sports Performance? A Systematic Review — Conde-Pipó J, Mora-Fernandez A, Martinez-Bebia M et al., 2024, systematic review
  4. The effects of intermittent fasting on body composition and cardiometabolic health in adults with prediabetes or type 2 diabetes: A systematic review and meta-analysis — Khalafi M, Habibi Maleki A, Symonds ME et al., 2024, meta-analysis
  5. Nutrition and Exercise Interventions to Improve Body Composition for Persons with Overweight or Obesity Near Retirement Age: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials — Eglseer D, Traxler M, Embacher S et al., 2023, meta-analysis
  6. Intermittent Fasting versus Continuous Calorie Restriction: Which Is Better for Weight Loss? — Zhang Q, Zhang C, Wang H et al., 2022, meta-analysis
  7. Intermittent fasting and weight loss: Systematic review — Welton S, Minty R, O'Driscoll T et al., 2020, systematic review
  8. A 5:2 Intermittent Fasting Meal Replacement Diet and Glycemic Control for Adults With Diabetes: The EARLY Randomized Clinical Trial — Guo L, Xi Y, Jin W et al., 2024, randomised controlled trial
  9. Effect of intermittent fasting 16:8 and 14:10 compared with control-group on weight reduction and metabolic outcomes in obesity with type 2 diabetes patients: A randomized controlled trial — Sukkriang N, Buranapin S, 2024, randomised controlled trial
  10. Brain responses to intermittent fasting and the healthy living diet in older adults — Kapogiannis D, Manolopoulos A, Mullins R et al., 2024, randomised controlled trial
How much research is there on intermittent fasting?
13 publications are indexed here, of which 3 are trials and 7 are syntheses.
Does more research mean a stronger conclusion?
No. Composition matters more than volume — five randomised trials support a claim far better than fifty commentaries, and citation counts do not distinguish between them.
How current is this?
The most recent paper indexed here is from 2025. The set is refreshed weekly from PubMed and Crossref.
Why does this page not tell me the answer?
Because summarising a literature into a conclusion requires reading it, and doing that automatically is how confident nonsense gets published. This page tells you how much weight a conclusion could bear; the articles on this site do the interpreting.

References

Every citation below links to the original peer-reviewed record on PubMed or via DOI. Nothing here is a substitute for medical advice.

  1. Longer-term effects of intermittent fasting on body composition and cardiometabolic health in adults with overweight and obesity: A systematic review and meta-analysis Khalafi M, Maleki AH, Ehsanifar M, et al. · Obesity reviews : an official journal of the International Association for the Study of Obesity · 2025 · Meta-analysis DOIPubMed 39501676
  2. Intermittent fasting strategies and their effects on body weight and other cardiometabolic risk factors: systematic review and network meta-analysis of randomised clinical trials Semnani-Azad Z, Khan TA, Chiavaroli L, et al. · BMJ (Clinical research ed.) · 2025 · Meta-analysis DOIPubMed 40533200Full text
  3. The effects of intermittent fasting on body composition and cardiometabolic health in adults with prediabetes or type 2 diabetes: A systematic review and meta-analysis Khalafi M, Habibi Maleki A, Symonds ME, et al. · Diabetes, obesity & metabolism · 2024 · Meta-analysis DOIPubMed 38956175
  4. Intermittent Fasting: Does It Affect Sports Performance? A Systematic Review Conde-Pipó J, Mora-Fernandez A, Martinez-Bebia M, et al. · Nutrients · 2024 · Systematic review DOIPubMed 38201996Full text
  5. Nutrition and Exercise Interventions to Improve Body Composition for Persons with Overweight or Obesity Near Retirement Age: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials Eglseer D, Traxler M, Embacher S, et al. · Advances in nutrition (Bethesda, Md.) · 2023 · Meta-analysis DOIPubMed 37028708Full text
  6. Intermittent Fasting versus Continuous Calorie Restriction: Which Is Better for Weight Loss? Zhang Q, Zhang C, Wang H, et al. · Nutrients · 2022 · Meta-analysis DOIPubMed 35565749Full text
  7. Intermittent fasting and weight loss: Systematic review Welton S, Minty R, O'Driscoll T, et al. · Canadian family physician Medecin de famille canadien · 2020 · Systematic review PubMed 32060194Full text
  8. A 5:2 Intermittent Fasting Meal Replacement Diet and Glycemic Control for Adults With Diabetes: The EARLY Randomized Clinical Trial Guo L, Xi Y, Jin W, et al. · JAMA network open · 2024 · Randomised controlled trial DOIPubMed 38904963Full text
  9. Brain responses to intermittent fasting and the healthy living diet in older adults Kapogiannis D, Manolopoulos A, Mullins R, et al. · Cell metabolism · 2024 · Randomised controlled trial DOIPubMed 38901423Full text
  10. Effect of intermittent fasting 16:8 and 14:10 compared with control-group on weight reduction and metabolic outcomes in obesity with type 2 diabetes patients: A randomized controlled trial Sukkriang N, Buranapin S · Journal of diabetes investigation · 2024 · Randomised controlled trial DOIPubMed 38932663Full text
  11. Health Benefits of Intermittent Fasting Reddy BL, Reddy VS, Saier MH Jr · Microbial physiology · 2024 · Review DOIPubMed 38955141Full text
  12. Clinical application of intermittent fasting for weight loss: progress and future directions Varady KA, Cienfuegos S, Ezpeleta M, et al. · Nature reviews. Endocrinology · 2022 · Review DOIPubMed 35194176
  13. Intermittent Fasting and Metabolic Health Vasim I, Majeed CN, DeBoer MD · Nutrients · 2022 · Review DOIPubMed 35276989Full text