How do you make your sims fat?

Make your your sim eat lots of snacks and deserts, even when they're not hungry. Also, don't let them do physical activity (exercising, yoga, sports), make them sit all day on the couch and watch TV all day. P.S. Make them get fat asses! Feed your sim loads of junk food when they are not hungry works, then once they have finished eating let them stand still for a while and they should get fatter!