Intermittent Fasting No Better Than Standard Diets for Weight Loss, Major Review Finds
A major scientific review has concluded that intermittent fasting is no more effective for weight loss than conventional dietary approaches, with minimal benefits compared to not dieting at all. Researchers analysed data from 22 global studies, involving nearly 2,000 adults, to assess the impact of popular fasting regimes like the 5:2 diet.
Limited Weight Loss and No Quality-of-Life Edge
The analysis found that individuals who are overweight or living with obesity lost similar amounts of weight through intermittent fasting as they did by following traditional dietary advice. Notably, fasting resulted in an average weight loss of only about 3% of body weight, which falls short of the 5% threshold considered clinically meaningful by medical professionals.
Beyond weight management, the review uncovered no strong evidence that intermittent fasting improves people's quality of life more than other diets. Dr Luis Garegnani, the lead author from the Cochrane Associate Centre in Argentina, emphasised that while fasting is not a miracle solution, it remains a viable option among various weight management strategies.
Surge in Popularity Amidst Evidence Gaps
Intermittent fasting, which involves restricting eating to set hours or fasting on specific days, has seen a dramatic rise in popularity. Proponents claim it aids weight loss, boosts physical and cognitive health, and may even slow ageing. However, this review highlights significant gaps in the evidence, with many studies being short-term and of poor quality.
Dr Garegnani pointed out that none of the 22 studies inquired about participant satisfaction with intermittent fasting, underscoring the need for more rigorous research. The Cochrane review employed gold-standard techniques to evaluate randomised clinical trials from regions including Europe, North America, China, Australia, and South America.
Expert Insights on Timing and Long-Term Effects
Dr Zhila Semnani-Azad from the National University of Singapore suggested that the timing of fasting could influence its benefits, given the connection between circadian rhythms and metabolism. Animal studies indicate potential advantages such as improved insulin sensitivity and reduced inflammation, but human evidence remains inconclusive.
Professor Maik Pietzner from the Berlin Institute of Health expressed surprise at the modest weight loss from fasting compared to no intervention. He noted that people often reduce physical activity while fasting, complicating weight loss efforts without pharmaceutical aid. His research indicates that short fasting periods have little effect on the body, with significant changes only emerging after prolonged periods without food.
In summary, while intermittent fasting may appeal to some individuals, this review reinforces that it does not offer superior weight loss or quality-of-life benefits over traditional diets, calling for cautious interpretation of its promoted advantages.
