The general attitude of a fat person. Your sterotypical person with a fatatude would be: fat, obnoxious, full of themselves, and loud. Often they are women, and often these women have stomachs that stick out further than their boobs. People with fatatudes often carry food with them at all times.
Ben: Dude, that bitch has a serious fatatude.
Jason: Yeah man, she really needs to stop piggin out.
"Mary has serious fatatude problems. Maybe she should lose some weight."
Also spelled fattitude, this word refers to the general attitude or vibe of an obese individual. This may include, but is not limited to, gratuitous eating of everything within reach, unwillingness to be photographed or seen in a bathing suit, and a trundling, constipated stride. A person with a fattitude may be stuck up or unreasonably self-important.
Boy, you better lose that fatatude before you end up looking like your 350-pound mother.