Treatments and supplements · Intermittent fasting
Does intermittent fasting work?
What we can tell you today: how thoroughly this has been studied.
Thoroughly studied
14 studies, of which 11 bring together the results of several trials in people. This is as strong as evidence gets.
5 Repeated evidence 11 studies
4 Large controlled trial 3 studies
This says how thoroughly something has been studied — not whether it works for you. What each study actually found is in the study itself, and in the plain-language write-ups we are adding.
Appears under: Weight loss and GLP-1
The studies
- 5 Repeated evidence
Intermittent fasting strategies and their effects on body weight and other cardiometabolic risk factors: systematic review and network meta-analysis of randomised clinical trials.
2025 · BMJ (Clinical research ed.) · 6,582 participants · manufacturer helped fund this
- 5 Repeated evidence
Missing puzzle pieces of time-restricted-eating (TRE) as a long-term weight-loss strategy in overweight and obese people? A systematic review and meta-analysis of randomized controlled trials.
2023 · Critical reviews in food science and nutrition
- 5 Repeated evidence
The Effects of Time-Restricted Eating on Fat Loss in Adults with Overweight and Obese Depend upon the Eating Window and Intervention Strategies: A Systematic Review and Meta-Analysis.
2024 · Nutrients · 1,288 participants
- 5 Repeated evidence
Intermittent fasting for adults with overweight or obesity.
2026 · The Cochrane database of systematic reviews · 1,995 participants
- 5 Repeated evidence
Effects of Time-Restricted Feeding and Ramadan Fasting on Body Weight, Body Composition, Glucose Responses, and Insulin Resistance: A Systematic Review of Randomized Controlled Trials.
2022 · Nutrients
- 5 Repeated evidence
Intermittent Fasting versus Continuous Calorie Restriction: Which Is Better for Weight Loss?
2022 · Nutrients
- 5 Repeated evidence
Does early time-restricted eating reduce body weight and preserve fat-free mass in adults? A systematic review and meta-analysis of randomized controlled trials.
2024 · Diabetes & metabolic syndrome · 859 participants
- 5 Repeated evidence
Beneficial effects of time-restricted fasting on cardiovascular disease risk factors: a meta-analysis.
2024 · BMC cardiovascular disorders
- 5 Repeated evidence
Efficiency of time-restricted eating and energy restriction on anthropometrics and body composition in adults: a systematic review and meta-analysis of randomized controlled trials.
2026 · The international journal of behavioral nutrition and p · 1,242 participants
- 5 Repeated evidence
Effectiveness of intermittent fasting to potentiate weight loss or muscle gains in humans younger than 60 years old: a systematic review.
2021 · International journal of food sciences and nutrition
- 4 Large controlled trial
Effect of a ketogenic diet, time-restricted eating, or alternate-day fasting on weight loss in adults with obesity: a randomized clinical trial.
2025 · BMC medicine · 160 participants
- 5 Repeated evidence
Time-restricted eating shows a modest reduction in fat mass in resistance-trained individuals: A systematic review and meta-analysis.
2026 · Nutrition research (New York, N.Y.)
- 4 Large controlled trial
Effects of 4:3 Intermittent Fasting on Eating Behaviors and Appetite Hormones: A Secondary Analysis of a 12-Month Behavioral Weight Loss Intervention.
2025 · Nutrients · 165 participants
- 4 Large controlled trial
An Intermittent Fasting Intervention for Black Adults Can Be Feasibly Implemented in Black Churches: A Cluster Randomized Controlled Pilot Study.
2025 · Journal of the Academy of Nutrition and Dietetics · 2,022 participants