Cellular energy depletion caused by fructose metabolism triggers a 'mayday' signal, leading the body to reduce metabolism, conserve energy, shunt calories into fat and glycogen storage, and increase hunger and thirst.

“it's like a may day signal this says we're under attack we're running out of energy and so it switches the animal into a condition in which they're trying to preserve their energy so they reduce their metabolism they reduce their expenditure they're resting the energy expenditure they shunt the energy that they're eating the calories they're eating into fat and glycogen as opposed to making more atp they're trying to protect the body by putting you into a system where you try to store fuel it triggers hunger and thirst that makes you want to eat more so you eat more to restore the energy but at expense that you're shunting much of it into fat and into fuel storage”