So much of it relates to consumption, and no one makes money from people eating less. People however make money from pushing gym memberships or active wear or supplements.

Everywhere from restaurants to supermarkets to chocolate bar companies to fast food all make more money if you eat more. There's no incentive to advertise eating less.

You don't see restaurants advertising smaller or even reasonable portions - it's always giant burgers or steaks or monstrous pizzas. In fact, it's a regular critique of fancy restaurants that they have tiny, considered portions. So, people instead eat until they're well-beyond sated. Day after day.