Intermittent Fasting Not Superior for Weight Loss, Meta-Analysis Finds
A Cochrane meta-analysis of 22 studies with nearly 2,000 participants found intermittent fasting is not particularly effective for weight loss in obese or overweight adults and does not differ significantly from standard dietary advice. Experts note it remains an alternative at least as effective as classic calorie restriction, but more long-term trials are needed.
A meta-analysis published in the Cochrane Database of Systematic Reviews concludes that intermittent fasting is not particularly effective for weight loss in adults who are obese or overweight, who showed moderate weight loss. The strategy also does not differ significantly from standard dietary advice or improvement in quality of life. The review included 22 studies with nearly 2,000 participants and evaluated various forms of intermittent fasting, including restricting food intake for most of the day and fasting every other day.
Experts responding to the study said the findings do not mean intermittent fasting is ineffective for weight loss. The president of the SEEDO Foundation and the Spanish Society of Endocrinology and Nutrition (SEEN) said the article does not say that intermittent fasting is not effective for weight loss; rather, based on the studies included so far, there is no evidence that it is superior to classic calorie restriction. Most researchers agree on this point and on the need for more clinical trials of longer duration to see if it offers more benefits than the classic low-calorie diet. However, there is evidence that it is an alternative for weight loss that is, at a minimum, as effective as classic calorie restriction.
A member of SEEDO and head of epigenomics at the Santiago Health Research Institute called the review rigorous and said it meets scientific standards for systematic reviews, but noted that the quality of many studies is limited and the follow-up period is short, so it is not the final word. Intermittent fasting can be useful in many cases, and if done correctly, it creates a state of nutritional ketosis that can confer health benefits because ketone bodies have antioxidant and anti-inflammatory properties and are signalling molecules that can modulate epigenetic mechanisms. This state has been observed to be associated with improved well-being and quality of life. The expert added that obesity is a chronic disease that must be addressed holistically and treatments personalised, with some strategies working for some people and others for others, depending on lifestyle, personal tastes and molecular and physiological profile, and always under the prescription of a nutrition or endocrinology professional.