Nicotine might make the brain think food is less filling than it really is, because it keeps the 'hunger signal' active even when you see food — so your brain doesn't realize you're about to eat and you eat less.

Nicotine makes two types of brain cells in the hunger center fire at the same time — one that says 'eat' and one that says 'stop eating' — which confuses the brain and leads to eating less.

When scientists remove a specific part of the nicotine receptor in the hunger center of mice brains, nicotine can no longer make them eat less — proving that part is essential for suppressing appetite.

Nicotine acts as an appetite suppressant via central nervous system activation of hypothalamic satiety pathways independent of tobacco-derived toxins.