A viral health simulation has shown exactly what happens when you go without food for 24 hours. Many people try intermittent fasting to lose weight, improve health, or “reset” their body — but the effects can be surprising.

According to doctors, fasting may improve gut health, lower blood pressure, and trigger autophagy — a process that removes damaged cells. However, it’s not suitable for everyone, especially if you’re pregnant, have type 1 diabetes, or a history of eating disorders.

Here’s what happens during a 24-hour fast:

• 4 hours: Insulin drops, and your body starts burning stored sugar.
• 8 hours: Blood sugar runs low, so the body uses glycogen for energy.
• 12 hours: Mini-ketosis begins, turning fat into fuel.
• 16 hours: Autophagy starts, recycling damaged cells and toxins.
• 24 hours: “Deep repair” mode kicks in, inflammation drops, and fat becomes the main energy source.

“Fasting can be powerful for health,” experts say, “but always check with your doctor first.”