Sam, Billie, Adam and Dan are four New Yorkers who are dealing with their individual eating disorders together. All four of them lean on one another for support and are good friends. They attend Belttighteners, which is a recovery program that approaches their issues extremely ruthless ways. Sam is trying to shape his date into a woman from a hot TV commercial, which horrifies Billie. Dan struggles with his choice for a gastric bypass surgery and Adam chases down a deliveryman for food.
Sam begins to date his colonic hydrotherapist only to realize he is jealous of the woman's other clients. Billie goes to visit her family and friends, but must deal with her father who always puts pressure on her to stay thin. Dan becomes so frustrated with his wife Amy, he pays a visit to an S&M submissive.
Dan' wife throws him out of the house after she learns about his sexual experiment. Billie begins to work out more, but discovers the reason behinds a girl's figure. Also, Sam is in pain after his scissors slip out of his hands during personal self-grooming.
Dan begins a fad diet while Adam is at risk of losing his job as a police officer. Sam is finally going on a date with someone he has been infatuated with for a long time. However, his girlfriend seems to be more into one of his friends.
At the gym Billie befriends a cancer survivor while Sam joins a yoga class to meet the instructor. Also Adam, who is a police officer, is caught by Internal Affairs for doing something wrong on the job.
Billie introduces her newest girlfried to her parents. Sam decides to try becoming a Vegan and Dan finally decides to get serious about having his gastric bypass surgery.
Despite Dan getting his jaw wired shut, his wife is not satisfied with his attempts to lose weight, and gives him an ultimatum: Lose the weight or lose me. After recieving this ultimatum, Dan leaves for a fat camp. Adam confesses to Belt Tighteners that he has been lying about not binging. As a result, he is kicked out of the group, and Sam, Billie and Dan leave with him. Sam finds out Adam has been kicked off the police squad, and after confronting Adam about it, finds out Adams girlfriend is imaginary. Under the influence of his girlfriend, Sam decides to become a breatharian - A group of people who live off sun and air and eat only "earth matter" once a month or so. Sam declares his love for Billie, but Billie, wanting to pursue her relationship with her girlfriend, rejects Sam. As a reaction, Sam buys a bag full of Nemo's and smashes his scale before eating them.
