Methodology

Why You Regained the Weight

Francesco Zen, founder of ZTraining · Last updated 20 June 2026

The mechanism

It's a simple process: the body slows down to avoid starvation when faced with sustained restriction. Once food is reintroduced and metabolism comes back up, the gap between what feels normal to eat and what the body is actually burning leads straight to overeating, and the weight that comes back tends to be fat and water, not the muscle that might have been lost along the way.

"You did not build a bigger fire, so you are burning less while being more hungry."

How to actually prevent it

The fix isn't avoiding food reintroduction, it's never creating the slowdown in the first place. An approach built around improving how efficiently the body uses food, rather than just restricting it, avoids setting up this exact mechanism.

He built Mr Z, an AI coach trained on his methodology to bring the same approach to a wider audience.