The premise of the show would be to trade with someone that eats too little and is unhealthy as a result, so they both learn about portion sizes and so on. Although I've only seen one superskinny character who I'd berate for her food choices. She just ate teeny portions of shitty food and looked sunken and ill and tried to blame it on being busy taking care of her kids and being frazzled. Fortunately she learned she should treat herself as well as she treats her kids