Whilst on a diet, Jon buys what is said to be a good, nutritious health food package, only for him and his pets find it to be the opposite.
While cooking, Jon reads about the sonic boom, something that moves faster than the speed of sound, which Garfield demonstrates when called for dinner. After Odie arrives to the dinner table, Jon reveals he is skipping dinner as he has picked up too much weight. Hungry, he turns on the television, and finds an infomercial disguised as a television show playing. Him and his pets find out that a woman named Sylvia Svelte is selling a delicious, dietary product, which entrances them.
The three arrive at her diet center, and meet Sylvia who, for an extreme price, sells them her seven day sample package. After they leave, she is revealed to have an aversion to her own food product when she asks for unhealthy food. When they arrive home, the three microwave their meals, and after opening the package, find the food to be minuscule and tasteless. This prompts Jon and Garfield to go back to her center, and demand a refund. After her bouncers to kick them out, Garfield realizes that he will have to fix the problem, and leaves for the filming studio.
After Sylvia appears onstage, Garfield appears backstage with a picnic basket. While she is advertising her product, Garfield opens the basket, and sets the air conditioning to its highest setting. The aroma travels through the vents, and Sylvia is able to smell it, which sends her into a state of hunger. This quickly makes her give up the dietary product, and she agrees to give Jon and her other customers their money back. She then asks Garfield how she can repay him, to which he asks her to pass the potato salad.
- When Jon turns on the TV for Sylvia's show, he asks "How come my TV always knows what I'm thinking?" This alludes to various episodes in the show where, whenever Jon has a problem, an infomercial that is airing seems to have a solution.
- Sylvia's first bouncer resembles Mr. Atweiler from Fair Exchange, and her second resembles the Parachuting Instructor from Jumping Jon.