Answer:
Approximately 24 hours.
Step-by-step explanation:
Our body has two complementary ways of energy storage. It can store energy as:
Glycogen in the liver.
Body fat.
Glycogen is both produced and stored directly in the liver. When insulin moves up, the body stores food energy as glycogen.
When insulin falls, as with fasting, the body breaks the stored glycogen back down into glucose. Liver glycogen lasts approximately 24 hours without eating.
Glycogen can only be used to store food energy from carbohydrates and proteins. It does not store energy from dietary fat, because it is not processed in the liver, and does not break down into glucose.