Mr Z

How Accurate Is an AI Chatbot Diet Plan?

Francesco Zen, founder of ZTraining · Last updated 19 June 2026

Where the error actually comes from

Most people can't accurately describe their own training intensity or which muscles they're really targeting. Compound lifts get treated the same as isolation work, and the formula inflates protein far beyond what's actually required, which throws off everything else built around it.

Carbohydrates are even more individual

Carbohydrate needs depend on glycemic response, which varies person to person far more than most plans account for. Two virtually identical bodies, same age, mass, gender, and muscle, can respond completely differently to the exact same meal. There's a genetic component to that response that a generic AI has no way to ask about, check for, or even know exists.

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