Obese mortuary cosmetician Grace Hart (Ricki Lake) lives in Queens and rides the subway everyday. Her somewhat unhappy existence is noted as she shops in a department store with her best friend, Keri (Nada Despotovich) a socially awkward and mousy coworker, and is rudely asked to please look at their "Large Ladies Department". That same night she and Keri are at a local skating rink when a young, attractive, amateur ice skater, Rob (Craig Sheffer), catches Grace's eye; she claims that he is the most beautiful man she has ever laid eyes on.
The following morning, Grace is wrapping a wedding present (a painted portrait of Grace and her father) for her butcher father, Al's (John Karlen), supermarket wedding. Grace's new stepmother, a cashier at the same supermarket named Wanda (Betty Buckley), claims to care but her sweet-talking attitude somehow always ends up insulting Grace in a passive aggressive sort of way instead of helping. When Grace is caught overindulging at the wedding, Wanda and Al express their concerns with "Grace, you have such a pretty face, but, if you don't lose weight, you never will find a boyfriend". To shut Wanda up, Grace lies and states that she already has a boyfriend. A surprised Wanda stares as she claims that she and Al would love to meet him.
On her way home, Grace is riding the subway when she notices that Rob is a New York City subway conductor. After following him around town a bit, she discovers that he is in a relationship with a woman named Olivia (Cynthia Dale). Grace observes the relationship as being rocky, with Olivia behaving in a very overbearing manner toward non-confrontational Rob. She decides to win Rob over, and eventually manages a meeting with him after his girlfriend leaves town to visit her family for the Christmas holidays. This meeting blossoms into a full-fledged romance, one that is lamented by Grace's overly pessimistic best friend Keri (Nada Despotovich). After Rob leaves for a New Year's party with Grace, Olivia arrives home to an empty house. She asks around at the ice rink where Rob likes to practice skating, where Keri reveals his secret relationship, along with their location that evening. Olivia in a fit of rage, confronts Rob and Grace at the club where he is partying, and beats Grace to the ground and calls her a "fat pig".
Grace goes back to being depressed and lonely and her father finally takes notice and tells her the truth about how her mother died (suicide) He was mainly worried about Grace because she looks a lot like her plus her mother like her struggled with her weight and he felt that the struggle was what lead to her depression and eventual suicide, and he was worried that Grace would end up following in the same fate. Grace later decides to quit being afraid of what the world thinks of her and to follow her own dreams. She applies to beauty school to become a full-fledged beautician and hairstylist.
The story concludes with Rob realizing that Olivia refuses to accept him as he is and that he truly loves Grace.