1992, Oxford, England. Frustrated and lonely, 16-year-old IVY BURNS, finds solace in literature and food. Her Professor father sends her to Boston where his old friend PROFESSOR CUNNINGHAM is pioneering a new obesity program.
Expecting low fat shakes and celery sticks, Ivy finds a plush clinic. Meals with dessert and group therapy. Mornings she’s given a hydration drip to burn calories. She meets ANNA, another patient, playing hockey.
At the end she’s lost 7 pounds and heads to New York. She orders cheeseburger and fries to celebrate. But her dish transforms into arthropods; the burger into beetles and fries into fleas.
At first it’s just junk food that transforms but soon ALL FOOD TURNS into BUGS.
Ivy is sickened and starving. Heading back to Boston, she confronts Cunningham. He tells her it’s the mind’s way of fixing the fat.
She meets Anna again, who’s experiencing the same thing. They break into the institute and find out the truth. Cunningham has found the reason thin people are thin: gallbladder bile. He took bile from thin cadavers and administered it to ‘fat’ people.
Caught by Cunningham they are locked in the food pantry and are overrun by scorpions, wasp spiders and millipedes. They fight back, eating their way out.
They get the patients out of the clinic. With hockey sticks as weapons they go after Cunningham. A fire starts. Ivy and Anna escape, but the clinic burns down with Cunningham inside. Ivy calls her father; she is not going back to Oxford.