Humans, as periodic eaters, need insulin to survive. Insulin helps the body release stored energy over time to fuel the body’s continuous needs and activities. Insulin is secreted after eating to move food components (glucose, amino acids, fatty acids) into the liver, muscle and adipose tissue (fat stores). As insulin levels diminish within an hour after eating, the hormone glucagon is secreted. Glucagon signals the body to begin releasing stored energy (glycogen from the liver and muscle, and fatty acids from adipose tissue) into the blood stream to fuel the body’s energy needs. This cycle is repeated with every meal. Whether one increases or decreases the size of their fat stores from day to day depends upon the overall relationship of calories consumed and absorbed versus calories burned (energy expended) through metabolism and daily activity. If you are in a caloric deficit at the end of the day, more fat would have been burned than stored, and fat stores would be decreased. However, if you are in caloric surplus at the end of the day, more fat would be stored than burned, increasing your fat stores. As you can see, insulin is a mechanism for amino acid, carbohydrate or fat storage for daily use. Insulin requires the consumption of excess energy (calories) in order to increase fat stores, but when energy intake is less than used, fat stores/mass will always be reduced regardless of hormonal interplay.