The balance of fat synthesise and degradation will determine changes in stored body fat.

If I eat nothing today, I will mobilise glycogen and body fat for energy and my total body fat will decrease.

But if I eat three times what I usually eat tomorrow, I will store the surplus energy as glycogen and body fat and my total body will increase.

Fasting isn’t necessarily required to release glucagon — it happens normally between meals and also overnight. On that note, eating smaller meals will stimulate glucagon release sooner after the meal, as there will be fewer nutrients to transport from the bloodstream into cells.