Well, you might be right: a new theory reckons it's addictive - just like cigarettes and drugs.
Our bodies could be getting hooked on the high levels of sugar and fat in junk food.
Scientists think chemicals called opoids released in the brain have something to do with it.
So you want more and more sweets or burgers.
It could explain why thirty-eight billion burgers are munched each year in the US.
But other scientists said there isn't enough evidence to prove it yet.
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