Devil's Food (1996)

When a TV anchor woman finds her career to be hampered by her uncontrollable weight problems, she closes a deal with the devil. He lends her her ideal weight, she promises him her soul. By contract. Soon enough she realizes she's made a terrible mistake and tries to negotiate her way out of it. Alas, the devil knows but one motto: "a deal is a deal", and now he's ready to collect...