Simply being uncontrollable doesn't mean that you're fat. There just aren't the thousands of examples that suggest obesity causes more weight gain than obesity does.
When we're talking about eating disorders, there are certainly those who choose to have them as an acceptable means of gaining weight. Those who want to binge-eat because it is fun to watch people eat while they exercise, or to gain weight as part of a performance of overeating. But there are people, like myself, who are fat, and it can be incredibly difficult for people who have obesity to understand how they might not want to consume too many calories. If anything, people who are fat simply get fatter over time. That makes it difficult to understand for people suffering from anorexia or other eating disorders how someone can have a low body fat percentage.
If this sounds dumb, that's because it is. This entire post was written by a bot. The image came from inspirobot, and the text came from Talk to Transformer. Seriously, check them out, they are a huge time sink that seem to surprise right when you're about to get bored.