Fasting-Mimicking Diet Shows Short-Term Benefits in New Clinical Study

A recent clinical study led by Valter Longo has explored the effects of a fasting-mimicking diet on weight, fat loss, and blood sugar levels. The research involved 100 participants who followed three monthly cycles of a five-day, low-calorie eating plan. Results showed reductions in body weight, abdominal fat, and blood glucose—though experts caution that long-term benefits remain uncertain.

The fasting-mimicking diet works by severely restricting calories for short periods. On the first day, participants ate around 1,000 to 1,100 calories, dropping to just 700 to 900 calories for the next four days. The diet is mostly plant-based, designed to trigger metabolic changes similar to those seen during fasting.

Findings from the study, published in scientific journals, indicated short-term improvements in weight, waist size, HbA1c levels, blood pressure, and inflammation. However, researchers noted that these benefits were partial and not necessarily better than those from traditional healthy diets. Side effects like hunger, fatigue, headaches, and irritability were also reported. Experts warn that repeating the diet too frequently without proper planning could lead to nutrient deficiencies. Intense exercise during the fasting phase is discouraged. After completing the five-day cycle, participants were advised to switch to a balanced, nutrient-rich diet inspired by Mediterranean eating habits. Despite the promising early results, most evidence on fasting-mimicking diets comes from small studies or animal research. Long-term effects on blood sugar, insulin resistance, and body fat composition are still unclear. Scientists stress that overall dietary patterns play a bigger role in health than short fasting cycles alone.

The fasting-mimicking diet may offer short-term benefits for weight and metabolic health, but its long-term effects are not yet proven. The approach is considered safe for healthy adults in five-day cycles, though it is not shown to be superior to standard nutritional advice. Further research is needed to confirm its lasting impact on health outcomes.