A systematic review and meta-analysis published in the Cochrane Database of Systematic Reviews on 16 February 2026 suggested that intermittent fasting provides no superior benefits for weight loss when compared to traditional calorie restriction or standard healthy eating.
What the 2026 Cochrane Review Tells About the Effects of Intermittent Fasting
Study Background and Main Findings
The conclusion was based on gold-standard techniques used to evaluate data from 22 randomized controlled trials involving 1995 adults across Australia, China, Europe, North America, and South America. Intermittent fasting was compared with standard dietary advice and no-intervention or control groups that received no dietary guidance or were on a waiting list.
Luis Garegnani, the director of the Cochrane Associate Centre at the Italian hospital of Buenos Aires in Argentina, headed the research. The methodology prioritized outcomes related to weight change and quality of life over a period of 12 months. Researchers examined how different fasting windows affected individuals living with overweight or obesity.
Specific results revealed that while intermittent fasting can result in a measurable reduction in body weight, the magnitude or actual significance of the change is often smaller than public perception suggests. The following points detail the more specific data points and observations recorded by the researchers during the systematic review and meta-analysis of the global trials:
• Weight Loss Magnitude: Participants on fasting regimes lost an average of 3 percent of total body weight. This remains below the 5 percent threshold that medical professionals define as a clinically meaningful improvement for human health.
• Comparison to Standard Diets: The data show that traditional calorie counting yields results similar to intermittent fasting and other variants of intermittent fasting. There is no statistically significant evidence that restricting eating to specific window hours provides an advantage over simply reducing daily caloric intake.
• Quality of Life Metrics: No strong evidence that fasting improves the well-being or daily satisfaction of participants more than other diets. None of the 22 studies specifically asked the participants about their satisfaction with the fasting routine.
Implications and Further Explanations
The findings suggest that intermittent fasting is not a miracle or go-to absolute solution for obesity or metabolic health. Furthermore, although intermittent fasting variations like the 5:2 diet and other methods remain valid options for some individuals, they do not offer a biological edge. The results align with the existing understanding of human metabolism.
Biological timing remains a critical factor. Several animal studies have revealed that fasting can trigger autophagy or improve insulin sensitivity. These beneficial cellular and metabolic processes usually occur beyond the 72-hour fasting period. However, human trials lasting 12 months or less do not consistently replicate these profound long-term cellular benefits.
A narrative review by K. Gabel et al. that was published in 2025 underscored the effectiveness of intermittent fasting in weight loss when partnered with physical activity. This combination helps in reducing fat mass and retaining lean muscle mass. However, in some cases, when people fast, they can become less physically active to conserve energy.
Researchers N. Lessan et al. also studied the effects of fasting during Ramadan on physical activity and energy expenditure. Specifically, using accelerometers, findings revealed that participants significantly reduced their total number of steps and moderate-to-high intensity activity during fasting hours to manage their energy. The paper was published in 2018.
FURTHER READINGS AND REFERENCES
- Gabel, K., Hamm, A., Czyzewski, O., Sanchez Perez, J., Fought-Boudaia, A., Motl, R. W., and Hibbing, P. R. 2025. “A Narrative Review of Intermittent Fasting With Exercise.” Journal of the Academy of Nutrition and Dietetics. 125(2): 153-171. DOI: 1016/j.jand.2024.05.015
- Garegnani, L. I., Oltra, G., Ivaldi, D., Burgos, M. A., Andrenacci, P. J., Rico, S., Boyd, M., Radler, D., Escobar Liquitay, C. M., and Madrid, E. 2026. “Intermittent Fasting for Adults With Overweight or Obesity.” Cochrane Database of Systematic Reviews. 2026(2). DOI: 1002/14651858.cd015610.pub2
- Lessan, N., Saadane, I., Alkaf, B., Hambly, C., Buckley, A. J., Finer, N., Speakman, J. R., and Barakat, M. T. 2018. “The Effects of Ramadan Fasting on Activity and Energy Expenditure.” The American Journal of Clinical Nutrition. 107(1): 54-61. DOI: 1093/ajcn/nqx016