What is more effective for weight loss, intermittent fasting or dieting?

Intermittent fasting may be as effective as traditional calorie-restricted diets for weight loss, according to a review of 99 clinical trials published in The BMJ .

The study, which included more than 6,500 overweight or obese adults, compared different types of intermittent fasting, including alternate-day fasting and time-restricted eating, with traditional diets and unrestricted eating.

Researchers found that all intermittent fasting strategies, as well as continuous calorie restriction, achieved modest reductions in body weight. However, alternate-day fasting was the only approach that showed a slight advantage over traditional diets , with an average additional weight loss of 1.29 kg.

Although these differences do not reach the threshold considered clinically significant (2 kg in obese people), the researchers note that alternate-day fasting was also associated with lower levels of total cholesterol and LDL ("bad") cholesterol , compared to other forms of fasting.

According to the authors, "Current evidence suggests that intermittent fasting diets offer similar benefits to continuous calorie restriction in both weight loss and cardiometabolic risk factors."

However, they stress that longer trials are needed to confirm these long-term effects.

Obesity continues to be a growing global problem. According to data from the World Health Organization , in 2022, 43% of the adult population was overweight, and 16% were living with obesity. Given this situation, sustainable approaches to weight loss are increasingly necessary.

In an editorial accompanying the study, Colombian researchers emphasized that the value of intermittent fasting lies not in replacing other diets, but in expanding the therapeutic options available to each patient. They also emphasize that the success of any dietary intervention depends largely on professional support, nutritional education, and long-term adherence.

"The focus should be on sustainable changes. Intermittent fasting is not intended to replace, but rather to be integrated into a patient-centered nutritional model," they conclude.