When people don't eat for 3 days, their insulin levels drop significantly, which is part of the body's adaptation to fasting.

When people don't eat for 3 days, their blood sugar levels drop significantly, from about 4.5 to 3.1 mmol/L.

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.

When people don't eat for 3 days, their adrenaline levels go up, but not until after the second day of fasting.

When people don't eat for 3 days, their noradrenaline levels go up, but not until after the second day of fasting.

When healthy young men only eat between noon and 8pm for five days straight, it doesn't change their baseline insulin levels