There's probably a lot of things going on inside a fat, from gastrointestinal distress caused by types of food eaten to physical pains and discomfort from the sheer amount of food their body moves each hour.  Not to mention the hundreds of pounds of extra weight fucking up their nerves and hormonal balances causing them to feel all sorts of strange things. I'm surprised we don't hear more of this.  Then again, who would willingly admit to being so fat you don't know you are pregnant?  That kid is so fucked for life.