A large review of about 22 studies with nearly 2,000 adults finds intermittent fasting may offer little to no advantage over traditional dieting for weight loss or quality of life.

There is substantial variation in fasting methods (8:16, 5:2, alternate-day fasting), making it inappropriate to treat all variants as a single approach.

Experts urge against hype, noting current evidence shows signals rather than definitive proof that interval fasting is superior.

The review cautions certain groups—pregnant or breastfeeding individuals, people with eating disorders, diabetes, or children—and calls for more diverse, longer-term studies.

Obesity is presented as a chronic condition, with short-term trials limiting guidance for long-term decisions and underscoring the need for more robust data.

People should choose a fasting approach they can sustain long-term, ideally under medical guidance, rather than chase trendy hype.

Physiological changes during fasting include higher HGH, better insulin dynamics, cellular repair processes, and potential gene-expression shifts related to longevity and disease prevention.

Weight loss remains the main strategy to reduce health risks tied to overweight and obesity, with cautious interpretation of general recommendations given the current evidence.

Long-term effects and adherence beyond roughly six months to a year are not well established, and reported side effects vary and are not definitively characterized.

The findings sit within broader public health context, noting high rates of obesity and inactivity in populations like England’s Health Survey data.

Takeaways include ongoing debates about fasting’s health impacts, mechanisms like autophagy and insulin sensitivity, and a call for higher-quality, longer-term trials to clarify benefits and protocols.

Limitations include inconsistent side-effect reporting, small trials, short follow-up, and a participant pool largely white and from high-income countries, limiting generalizability.