What happens to your body when you skip food for 3 days?

Intermittent fasting without daily fasting maintains higher metabolic rate while still providing metabolic benefits.

Prolonged fasting (72 hours) impairs glucose tolerance, resulting in higher blood glucose and insulin responses to carbohydrate intake.

Specific intermittent fasting patterns (one 36-hour fast per week, two non-consecutive 24-hour fasts, or three separate 16-hour fasts) increase norepinephrine, fat oxidation, and glucose tolerance while avoiding metabolic downshift.

When people don't eat for 3 days, their heart rate goes up, increasing from about 62 to 69 beats per minute, with most of the increase happening within the first day and a half.

When people don't eat for 3 days, their body burns calories at a slightly higher rate for about a day and a half, then returns to normal levels.