Study Finds Intermittent Fasting More Effective Than Traditional Calorie Restriction for Weight Loss

A recent study from the University of Colorado School of Medicine has shown that intermittent fasting—specifically a regimen known as “4:3 fasting”—may be more effective for weight loss than conventional calorie-restricted diets.

The 4:3 fasting method involves eating normally on four days of the week, while limiting food intake significantly on three non-consecutive days. On these fasting days, women consumed around 400 to 600 calories, and men approximately 500 to 700. Participants in the study were adults between the ages of 18 and 60, all considered overweight or obese according to standard medical definitions.

Over the course of a year, those following the intermittent fasting plan lost an average of 7.6% of their body weight—compared to a 5% reduction in the group that followed a daily calorie restriction. Moreover, those on the fasting schedule were more likely to adhere to the plan and less likely to drop out of the study. These results suggest that for many, intermittent fasting may be a more manageable and sustainable method of improving health and losing weight.

For members of the frum community, the flexibility of intermittent fasting could offer a practical advantage. The approach may allow individuals to eat normally during Shabbos and Yom Tov without guilt or confusion over calorie counting, while utilizing other days of the week for mindful eating and restraint.

Individuals with underlying health conditions or those who are pregnant, nursing, or elderly should speak with their physician and, when appropriate, a Rav to ensure that any such approach is safe and suitable. Health is a gift from Hashem and preserving it is a responsibility incumbent upon each Jew, as the Torah teaches, “ונשמרתם מאוד לנפשותיכם”.