Actually a legal and vital life drug, even if it's not recognised as one, it's still technically one.
DEFINITION OF DRUG: "Any substance intended to affect the structure or any function of the body of humans or other animals."
You need FOOD, a substance, to function therefore it is a drug, and it can change the structure of your body too, literally.
Like other drugs; food can be addictive. Just look at obese people, and like other drugs, it can be avoided. Just look at anorexics.
For some people, eating can make you feel happy, and like all drugs and over-dosing; over-eating leads to negative consequences (obesity, which can mean heart diseases, etc.)
People need food like pothead needs weed, like perverts need sex, and like alcoholics need vodka and whiskey.