Artificial sweeteners and highly processed foods can shut off your "I'm full" safety valve.
Read the labels on the foods you eat, educate yourself.
Corporations want you to eat to excess, it's profitable.
Heard from sci show that they make you crave sugar more since they are stronger than real sugar. Also, they make your intestines absorb more sugar since the sugar receptors get clogged trying to absorb the artificial stuff and they pull more. That second one probably doesn't affect you very much though.