I absolutely believe they eat out of enjoyment. Sure, there are probably other reasons such as a mechanism to self loathing and chemical reactions of dopamine in response to particular substances like caffeine. But if it is literally just about having any kind of food in their mouths, then why are there so many fats who despise or completely disregard trying healthy foods? Show me a fatty shoving a whole cake into their gaping maw and I'll show your happy fatty. Show me one with endless kale and salmon and I'll show you a suicide watch possibility.