After being forced to go on a diet of healthy food thanks to Nani, Stitch believed that it was time to take matters into his own paws. So, he decided to reactivate one of his cousins, Experiment 062. Lilo had dubbed him with the name Frenchfry on account of his french. Frenchfry was created by Jumba to be his personal chef. His main purpose was creating delicious and irrestiable meals. However, there was a catch.
The meals that Frenchfry made had zero nutritional value. Which meant the food resulted in zero calories. So while eating his food led to massive bloating, someone who eats his food would never feel full no matter how much they have eaten. Because of this, Lilo, Stitch, and Pleakley decided to continue to eat even more of his food even with them all becoming giant bowling balls.
Realizing that she was late for her hula class, Lilo quickly rolled out of the house. Leaving Frenchfry in the care of Stitch and Pleakley. Oh rather, Stitch and Pleakley were in the care of Frenchfry. Since it seemed that they were running out of more food. So Frenchfry spinned around again and made more food in an instant. Burgers, pizza, and fries galore.
"Bon appétit!" Frenchfry said after making more food and having his spatula in his paw.
"Ooooh! More!" Stitch went in awe after seeing more of the taste food made by his cousin.
"Well, it would be a shame to let it go to waste." Pleakley went as he eyed the food.
"Ekk!" Stitch said his way of saying yes.
So Stitch and Pleakley went back to feasting on more of Frenchfry's cooking. Little did they know, Frenchfry had bigger plans in store. There was a reason why Frenchfry was feeding them so much food. It was to fatten them up to the right amount so when they were at the peak of plumpness, he would eat them himself. It was the flaw in 062's program. Also, Jumba was the one who created him. Jumba wouldn't be an evil scientist if his experiments weren't.
Pleakley went up to his room and Frenchfry just send him food up there. But.... his real focus was on Stitch. Compared to the two, Stitch seemed like the best choice to fatten up the most. After grinning sinisterly, Frenchfry offered Stitch a huge platter of cupcake.
"Dessert?" Frenchfry asked his blue cousin.
"Cupcakes!!!" Stitch said sounding a bit too eager.
Not even wasting any time, Stitch grabbed the platter and chucked all the cupcakes in the air, opened his mouth wide, and shallowed them all. The moment he shallow them, the next moment his belly swelled up quite a bit. Stitch didn't even seem to notice. Frenchfry then offered Stitch even more cupcakes and the blue fuzzball continue to stuff his face more and more. Not just cupcakes, but doughnuts and slices of cake by the bundle. Eventually, Stitch's body bloated up more and more from all the eating. But instead of staying round, his belly started becoming blob-like as the chair he sat on finally broke due to his weight.
Stitch now looked like he could outdo a sumo-wrestler. He was far from being the same blue alien he was. He was now at the point of immobility. Fatten up to the point he was taller than the fridge and twice as wide. He couldn't even roll now due to his new shape. His arms even started to add pudge and getting close to be hidden in it. There was even a ring of fat forming around his neck. As fat as Stitch was getting he still couldn't help but want more and more.
"More! More!" Stitch uttered.
"Alors plus vous obtiendrez (Then more you shall get.)." Frenchfry said still will to make more.
Frenchfry then whipped up even more fattening dishes in large portions. Stitch went from gulping down some of the food to shallowing them whole. Not even wasting time chewing. And with every eaten treat, Stitch fatter and fatter. Soon, he even started to fill up the entire kitchen with his flabby body. After barely leaving any room to move in the kitchen, Frenchfry believed that Stitch was almost at the peak of plumpness. He just needed to be fed one.... more.... thing.
The last dish Frenchfry had prepared for Stitch was a HUGE three-layer cake with chocolate frosting. Unlike some layer cakes where the biggest layer is the bottom and the upper ones were smaller, Each layer was equally the same size. The cake also looked very dense. Even with Frenchfry lifting the cake with ease, three or four regular people would have trouble lifting it. One more thing, the cake was frosted properly and topped with a few strawberries. You know, cause it needed to have some type of fruit on it.
"Bon appétit!" Frenchfry said again a bit more sinister than before.
"Oh. Cake looks.... big. And.... tasty." Stitch said looking a bit surprised. "Stitch not sure he should eat it since Stitch has already ate so much." While he said those words, the drool falling from his mouth said otherwise. "Yet, STITCH CAN'T RESIST!!!"
Stitch then took multiple handfuls of cake and shoved it down his throat. After that, he just decided to shove the whole cake down his gullet. The cake didn't even last 3 seconds. After finishing the cake, Stitch licked his lips feeling very pleased with himself. After that, something big was definitely about to happen. Stitch's whole body began to rumble creating a small shake throught out whole house. Then, came the bloating. 
Stitch's body fatten up to every corner of the kitchen at a fast pace. Ever faster than Frenchfry expected.
"Sacré bleu!" Frenchfry said frantically as Stitch's flab began to corner him.
It wasn't just the kitchen Stitch was filling up. It was the slowly becoming the entire house. From the out of the kitchen to the living room to the second floor, more and more of the house was started to be filled up with Stitch's blue blubber. The structure of the house didn't seem like it was going to hold Stitch any longer. 
Then eventually.....
BAAAAAMMM!!!!
Stitch had now fatten up so much that he was now the size of the house with the actually house being reduced to rumble. Stitch then let out a mighty belch that probably could be heard all over Hawaii. He was now just a massive immobile blubbery blue alien. After Stitch exploded with fat, Frenchfry had seemed to have been knocked out. So it looked like his own plan failed. Also, poor Pleakley was trapped somewhere under Stitch's flab. But he.... probably okay. While it didn't seem like Frenchfry would eat him now, Stitch now had a bigger problem. What was he going to tell Lilo and Nani about the house? Also, he was actually still hungry.