What happens to your body when you starve yourself for 2 days?

Answer 1

During fasting and starvation, the body priorities are to supply sufficient glucose to the brain and red blood cells, and to preserve protein. During starvation days 1-3 your blood glucose is maintained by the liver breaking down glycogen stores (which deplete after day 1) and creating new glucose, fat cells releasing free fatty acids. Your muscle and liver will begin to shift from using glucose for fuel to free fatty acids.

After day 3 your fat cell stores become your main source of energy for the brain, through the creation of ketones. After these are depleted, the body will begin to accelerate the degradation of vital proteins, which will eventually lead to organ failure and death. Your amount of excess stores of these will determine the survival time in that scenario.