Throwing up from greasy/"fatty" foods?

Human digestive systems can't process oils and fats due to the composition of them. So possibly its your system trying to kick it out of itself by any means possible. To help don't drink cold beverages with greasy food something hot will keep the fat and stuff from solidifying in your stomach. Also I'm guessing when you eat fast food you walk around and stuff afterward so that helps the process from making you sick. Also theres bread and other stuff on the sandwich that either soak up the grease or just help it p through. Drinking hot beverages will also help you lose weight if you want to do that too.