"You" don't crave stuff, the microbiome in your intestine craves stuff.

There are microbes in there that specialize in eating, say, sugar. You don't give them sugar, they send signals to your brain saying "yo, more sugar"

This is why if you go on a sugar-free diet (just stop eating candy and sweets) the cravings just go away eventually. The microbes who keep shouting for more sugar either die away or go dormant.