Lilo and Stitch arrive downstairs for breakfast and find Nani cooking instead of Pleakley, who went to drop Jumba off at the airport. Nani serves them oatmeal for breakfast, which Lilo and Stitch refuse to eat. It is at this point that Nani realizes that Pleakley has been letting Lilo eat junk food, disregarding her health. When he gets back from the airport, Nani instructs Pleakley to make sure she eats the nutritious meals she has prepared for her in the fridge. As before Lilo and Stitch refuse to eat the meals Nani has prepared, and decide to go on a hunger strike. Even Pleakley shows disgust towards healthy food. When Nani comes home for lunch and finds that none of them are even trying to eat healthy, she decides to ban all junk food in the house.
Nani confiscates Pleakley's hidden stash and takes it to the trash. Then firmly instructs him to prepare a nutritious meal by the time she gets back from work. "No more junk" she says. With everyone now worried, Stitch looks into Jumba's draw and brings out an experiment pod, numbered 062. According to Jumba's computer, Experiment 062 is designed to prepare delectable and irresistible meals. They waste no time activating 062, who straight away begins cooking up a delicious unhealthy meal for Lilo, Stitch, and Pleakley. He prepares a large amount of hamburgers, french fries, pizzas and ice cream Sundaes. Lilo, Stitch, Pleakley dig in, consuming everything on the table. Little do they know that they are starting to grow fat as they eat. After eating ten burgers (Pleakley ate twelve), fifteen pizzas, nine Sundaes, and many plates of fries, Lilo, Stitch and Pleakley become all round and fat. Strangely enough, neither of them feel full. So, they decide to keep on eating, which makes 062, now called Frenchfry, give off a devious smirk.
Lilo does not notice the side effects of Frenchfry's meals until she realizes she is late for Hula class. She shows up, but accidentally rolls over everyone like a bowling ball. Eventually, Lilo and Stitch decide to look up more on Frenchfry. Apparently, they find nothing that helps explain the reasons behind the extra weight they've gain while eating Frenchfry's meals. All they got from a video diary was that 062 was designed to be Jumba's personal chef but curiously had trouble resisting his meals and never felt full. Frenchfry gets Lilo and Stitch eating again, and they get more fatter. Just then, Gantu shows up to capture Frenchfry. Despite being overweight, Stitch still manages to take on Gantu by bouncing on him. Because it is also his birthday, Frenchfry tempts Gantu with a birthday cake, which he consumes and suddenly grows fat. After Gantu retreats, Lilo decides to call Jumba.
Meanwhile, Jumba is in the middle of presenting his genetically engineered house pet to the scientific community when he gets a call from Lilo. She asks him about Experiment 062, and when she tells him that they reactivated him Jumba warns her to resist eating his meals. It turns that Frenchfry is actually trying to fatten them up so he can eat them himself. This is proven right when Frenchfry takes Lilo and Stitch into the yard where he prepares a fire to cook them on. When Nani hears from Moses of what happened at Hula class, she calls Jumba as well. He confirms that Lilo and Stitch had gotten fat due to overeating Frenchfry's meals, which will wear off after twenty-four hours. However, he warns her that his experiment will try to eat them and must hurry home. Nani arrives just in time to save Lilo and Stitch, and battles against Frenchfry. With Lilo and Stitch's help, she beats Frenchfry and traps him under a swimming pool. Meanwhile, an overweight Gantu arrives back on his ship and finds his former colleagues greeting him "Happy Birthday", much to his anger as he states that it isn't his birthday, even though it is.
The next day, Lilo, Stitch and Pleakley are back to normal. Nani again serves them oatmeal, but this time cleverly entices Lilo that it is actually "mummy chow". This encourages her to eat her oatmeal, along with some "ectoplasmic slime". Frenchfry has also taken a liking to Nani's oatmeal, and vows to make healthy meals and never again try to eat people.
- Moral: It's important to eat a healthy, well-balanced diet.
- It is unknown why Gantu denied the fact that it was his birthday when Reuben mentioned it to him.
- We learn that Jumba keeps self-made video diaries for his computer, explaining his thoughts or the results of his illegal experiments.
- Gantu is revealed to have invented a "trog call" to capture experiments more easily.
- Despite Gantu stating that he hates sweets, he did not turn down the cake that Frenchfry made him. Though this could be attributed to Frenchfry's ability to make food irresistibly delicious.
- Frenchfry is the first and only known experiment that Nani caught.
- He is also one of the few known experiments to be rehabilitated by someone other than Lilo and Stitch.
- Gantu's college football team appears near the end of the episode.