Overview
- Researchers pooled 22 randomized trials published from 2016 to 2024, covering 1,995 adults across North America, Europe, China, Australia, and South America.
- Across methods such as time‑restricted eating, alternate‑day fasting, and the 5:2 approach, weight loss differed little or not at all versus conventional calorie‑focused advice or no structured program.
- The authors expressed moderate confidence in the weight‑loss finding, while labeling evidence for other outcomes as very uncertain.
- Adverse events and quality‑of‑life measures were rarely or inconsistently reported, and most trials were short term and centered on predominantly white participants in high‑income countries.
- Experts say any weight change likely reflects reduced calorie intake rather than fasting‑specific physiology, and advise personalized, sustainability‑focused care while calling for longer, more inclusive studies that track metabolic markers, adherence, and harms.