Intermittent fasting has similar benefits to classic diets based on eating less | Health

Humanity is experiencing an unprecedented physical transformation. Since 1990, obesity has more than doubled among adults and quadrupled among teenagers, according to data from the World Health Organization (WHO). One in eight people worldwide is obese. And almost half of the population is overweight, due to a sedentary lifestyle and junk food. Three months ago, the organization’s director general, Tedros Ghebreyesus, posted about the importance of weight loss to reduce the risk of cancer and cardiovascular disease by exercising and adopting a healthy diet, without alcohol or sugary drinks. An analysis of 100 medical studies now endorses an increasingly popular strategy: intermittent fasting.

There are many ways to restrict calorie intake, but the new study focuses on three types: eating every other day, fasting for two consecutive days each week, or skipping a meal each day to accumulate, for example, 16 hours without eating. The analysis, which includes more than 6,500 people, suggests that the three types of intermittent fasting offer “similar benefits” to those of traditional diets that involve eating smaller amounts of food. The authors highlight the similar effects on both body weight and the reduction of major cardiometabolic risk factors, such as blood pressure and blood glucose levels. The study was published this Thursday in the medical journal The BMJ.

Alternate day fasting is the only practice that achieves greater weight loss than traditional diets that focus on eating less: around 1.3 kilograms (2.9 lb) more weight loss after 12 weeks. This strategy also lowers bad cholesterol more than skipping meals. Previous studies have already shown that alternate day fasting helps people lose up to 6 kilos (13.2 lb) in 12 weeks.

Dr. Jordi Salas Salvadó, a professor of nutrition at the Rovira i Virgili University in Reus (Tarragona) and one of the study’s co-authors, emphasizes that none of these methods are necessary if you’re already at a healthy weight. “And these results don’t mean that everyone who is obese should start intermittent fasting. It’s another strategy worth considering, especially for those who are tired of traditional diets. A professional can recommend intermittent fasting without any problems,” he notes. “I’m of a normal weight and have never done intermittent fasting. One day I might have yogurt and fruit for dinner, but that’s because I don’t feel like anything else,” he underscores.

Weight loss reduces the risk of chronic problems such as type 2 diabetes and cardiovascular disease, according to the authors, led by nutritionist John Sievenpiper of the University of Toronto (Canada). The analysis exhaustively reviews 100 studies conducted in 24 countries, including Spain, Mexico, and the United States. The results have several limitations, such as the heterogeneity of the participants, which makes comparisons difficult. The follow-up time, about 12 weeks on average, is also short, so the authors acknowledge that longer clinical trials are needed to support their conclusions.

“We already knew that traditional calorie-restricted diets work both in the short and long term. Now we also know that intermittent fasting works, at least in the short term. It’s another strategy,” Salas Salvadó sums up.

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