Timmy wishes that everyone ate nothing but dessert, which at first leads to rushes in energy. Over time though, everyone becomes overweight, which Timmy sees as a partly good thing: No one is made fun of for being fat, and Francis tries to pick on thin kids (Mark Chang) but is too fat to even move! But the huge increase in weight is causing the Earth to crash into the Sun!
When Timmy doesn't want to eat his spinach, he throws it away and is vaporized by Cosmo & Wanda and then when he asks for dessert, his mom gives him carrot cake without the cake. Then Timmy tries A.J.'s house but finds out that he must multiply fractions for dessert and then at Mark Chang's place, where he had ice cream but it has vegetables. After that, Timmy wishes for no breakfast, lunch, or dinner, just desserts. Then Wanda explains that eating healthy gives one the energy. Timmy then started saying chocolate in his sentences, making Wanda go crazy. She tells Timmy to make the wish. Cosmo said he is not usually the sceptical one, and tries to explain what happens to Wanda eats a lot of sugar, as Wanda puts him in a bubble before he could say what happens, so Timmy makes the wish. The next morning his mom called him and gave him a cake and 3 bars of chocolate and a bowl of frosting. At school everybody is eating desserts and school is only 3 minutes and everything is in the rush, the sugar rush hour, and other things. The school serves ice cream sandwiches for lunch which Wanda devours. Cosmo sees Wanda's LOW FAT stamp and comments she won't stay that way. Later Cosmo explains what will happen if Wanda eats to many sugars and explains what would happen to Dimmsdale but does not know. 28 days later, everybody is enormously fat. Everyone has lost the sugar rush energy. Timmy's bed snaps under his weight. Cosmo and Wanda poof into their fish bowl, which can barely contain the two. Timmy's Dad then has to roll Timmy down the stairs. Cosmo and Wanda are too heavy for their wings to lift them and stay in Timmy's room to eat. The school bus collapses when it reaches school. In school everyone is forced to roll except for Mark Chang since Yugopotamia's dessert are healthy foods. Francis tries to stuff Mark Chang into a locker, but he doesn't have any energy to bully anyone anymore. In Mr. Crocker's room he explains what would happen if Dimmsdale gets too heavy: the Earth hurtles into the sun. Then it's snacktime. The kids cheer and open their desks. They eat more desserts, and everyone in the class gets heavier. Trixie eats a giant cookie which causes her belt to snap due to the massive size and weight of her stomach and buttocks. The large bellies cause the chairs to sink to the floor and then Dimmsdale went to the bottom, causing the Earth to start hurtling into the sun with a molten date with death (as stated by Sanjay) and then everybody in the room escapes. Timmy rolls back to his house but is too fat to climb the stairs. He then does a butt slam which causes the ceiling to break and his FattyGod Parents to come down to him. He tries to wish everything back to normal but Wanda does not have enough energy to lift her arms. Timmy goes to Mark Chang's spaceship and tries to get his last can of spinach cobbler. At first, Mark Chang declines, but after Timmy sits on him, he lets him have the can of spinach cobbler, and Mark Chang drops Timmy off (literally) at his house by using his ship. When Timmy gets back, he forces the spinach down Wanda's mouth. (He landed on her) Wanda then has a brief period of energy which Timmy uses to wish everything back to normal. Timmy learns his lesson of eating healthy food, but Cosmo still has his extra weight. Wanda then is revealed to be stuck somewhere in Cosmo, he tries to retrieve her out of him, but finds only a cowboy hunting another cowboy called Billy the Goat.
Timmy's Mom would have appeared bouncing around the house. Vicky would have appeared as the fattest and heaviest due to her hogging all the desserts. Both were cut for time.