What disease is it that causes someone to routinely consume far more calories than required for their body to operate?

Excess food consumption is not a disease.

Now you can certainly argue, and quite effectively, that excess food consumption is addictive behavior, nearly identical to drug or alcohol abuse, but it's not a disease. There are conscious decisions made, and repeated. You are eating the donuts. You are drinking the vodka. You are shooting the heroin. You are smoking the cigarette. The substances might be addictive, but there is still an active and continuously ongoing decision making process going on.