Doctors must adopt an individualized approach for each case when advising adults with overweight on weight loss,” states Eva Madrid. Obesity requires personalized treatments Obesity is a major public health problem that has become one of the leading causes of death in high-income countries. However, the quality of many studies is limited and the follow-up is short, so it is not the last word,” states Ana Belén Crujeiras, head of Epigenomics at the Endocrinology and Nutrition group of the Santiago de Compostela Health Research Institute (IDIS), in a reaction collected by Science Media Centre. Crujeiras explains that if intermittent fasting is done correctly, it creates a state of nutritional ketosis that can confer health benefits, as ketone molecules have antioxidant and anti-inflammatory properties. «It has been observed that this state of nutritional ketosis is associated with better well-being and quality of life», she points out. Nevertheless, the researcher emphasizes that obesity is a chronic disease, and its treatment must be personalized and always under the prescription of a nutrition or endocrinology professional. «Some people respond to one therapeutic strategy and others to another, depending on their lifestyle, personal tastes, and their molecular and physiological profile”, she concludes. The largest review of the scientific evidence to date on this practice, heavily popularized on social media for its «metabolic benefits», indicates that it is no more effective than dieting or leading a healthy life. The meta-analysis published this Monday by the Cochrane System has included 22 studies on intermittent fasting, with nearly 1,995 adult participants from North America, Europe, China, Australia, and South America who were followed for 12 months. The review evaluates the various modalities of intermittent fasting, including alternate-day food restriction, periodic fasting, and time-limited feeding. The researchers, including Eva Madrid from the Sant Pau Research Institute in Barcelona, compare intermittent fasting with traditional dietary advice for not gaining weight and with what happens when there is no intervention. The evidence does not justify the enthusiasm Their conclusions point to that intermittent fasting is not particularly effective for weight loss in adults with obesity or overweight, who showed moderate weight loss with this practice. Additionally, the authors also do not see any significant difference compared to usual dietary advice or to improvements in health habits. “Intermittent fasting could be a reasonable option for some people, but the current evidence does not justify the enthusiasm we see on social media towards this practice,” states one of the authors of the review, Luis Garegnani, a researcher at the Italian Hospital of Buenos Aires. The researchers recognize that there are still few studies that have studied the long-term impact of intermittent fasting. Considering that obesity is, precisely, a long-term disease, this makes it difficult for intermittent fasting to have strong scientific backing, at least for now, to be clinically recommended, they state. Most of the included studies predominantly recruited white populations in high-income countries. According to the WHO, 2.5 billion people in rich countries suffered from overweight in 2022, and of them 890 million suffered from obesity. “We are facing a rigorous review. For this reason, the authors warn that their results may provide clues, but they cannot be extrapolated to the entire population, as they may vary according to sex, age, ethnic origin, the state of the disease, or underlying eating disorders or behaviors. “With the current evidence available, it is difficult to make a general recommendation”.
