A comprehensive analysis of global clinical studies has found that intermittent fasting is not significantly more effective for weight loss than traditional diets or even doing nothing. This finding comes as intermittent fasting, which involves restricting eating to certain hours or days, has gained popularity as a strategy for weight management, often promoted by celebrities and social media influencers.
Researchers examined data from 22 randomized clinical trials involving nearly 2,000 overweight or obese adults from North America, Europe, China, Australia, and South America. The studies looked at different patterns of intermittent fasting, such as alternate-day fasting, the 5:2 diet, and time-restricted eating. Most of the trials ran for up to a year. The review, led by Dr. Luis Garegnani from the Italian Hospital of Buenos Aires, found that people lost about the same amount of weight whether they practiced intermittent fasting, followed a conventional reduced-calorie diet, or made no changes to their diet at all.
The average weight loss with intermittent fasting was only about 3% of body weight, considered below the 5% threshold that doctors view as clinically meaningful. The scientists also noted that the benefits of intermittent fasting for quality of life were not greater than those seen with other types of diets. Despite claims that intermittent fasting can have extra metabolic or anti-aging benefits, the review did not find strong evidence to support such outcomes, at least in the short-term studies reviewed.
Some experts caution that most of the research to date is short in duration and often with small numbers of participants. There are also uncertainties about whether participants fully followed the prescribed fasting regimens, which could influence results. Additionally, the definition of intermittent fasting varies across studies, making it hard to compare outcomes.
Medical professionals say weight loss approaches need to be tailored to the individual, taking into account personal preferences, lifestyles, and medical conditions. While intermittent fasting can be considered a valid option, experts emphasize the importance of professional guidance and a comprehensive approach to addressing overweight and obesity. Further research is necessary to determine the long-term effects and broader health impacts of intermittent fasting compared to standard dietary methods.
