Why are some fat people afraid to eat in front of others?

Not just fat people, but thin people and normal sized people have this problem sometimes, especially people with eating disorders, as I do. They feel embarassed for any amount of food that goes into their mouth. For some overweight people, it may be because they don't like the thought that they may gain weight and be heavier. For people with eating disorders(as even overweight people can have) they feel like they don't deserve to eat, for deeper physcological reasons. Possibly you can just pull your friend aside and say that you won't judge them no matter what their size or how much they eat. Good luck.