Lisa had not always been this way.

Once, she had been light, skinny, just the same size as everybody else. A girl distinguishable by her academic achievements and great brain, not her size. She could still remember when Üter was fatter than her, when it seemed ludicrous to anyone that a human could pass Üter in size. Now, of course, those days were long gone- ever since that day, a day whose date she could no longer remember, everything had changed.

She still did not know what happened that day, the day she sat down at lunch like any other. In truth, it was Martin Prince's doing, a small addition to her hamburger as revenge for her scoring better than him in the science fair. The cause, in truth, was immaterial- it was the effect that lasted. Upon finishing that hamburger, Lisa was struck with a hunger like no other, a raging fire in her stomach that refused to be quenched. She finished her lunch, which normally would have been difficult for the middle Simpson, and ran for a second, then third, then fourth... By the time she had finished seven full trays, she was bloated beyond belief. Her yellow stomach had shredded her dress, leaving it on sauce-covered display for all the cafeteria. Laughter rang out around her, her own "dear" brother laughing loudest of all. Martin had won the day. His formula summarily wore off a few hours later, as planned, and all should have been well.

But that lunch awakened something in Lisa- something that, for a while, even she didn't recognize was there. She swore to cut down, and, the next day, only ordered one lunch. But, after clearing the tray and a bit of forlorn reflection, she decided that, after all, a second tray couldn't hurt too much. Not being driven by any science, she didn't finish it, leaving about a quarter to be tossed away. But, over time, that quarter disappeared from future lunches, and the tray count climbed again.

The changes were slow at first- clothes pinching, a bit of chin forming under the usual one. But, seconds, then thirds, at every meal soon made their presences known. Lisa ballooned at a quite astronomical rate, going through clothes- and food- like nobody had seen before. Soon, her large, yellow belly had divided itself in twain, the lower roll of which necessitated tucking into pants already straining with an impressive butt. She zoomed past Wendell, then Martin, then Ralph, then, finally, Üter, all the while enduring countless ribbing from Bart and even some of her other classmates. To escape, she ate even more, snacking and snacking until the insults couldn't bother her any more. Until, one day, she discovered she couldn't fit even halfway into her desk, and, to peals of fourth-grade laughter and the disgruntled sighing of Miss Hoover, she resolved something would have to change.

It did. She upgraded to a larger desk.

From there, her weight continued to go up, whizzing through 200 to reach 300- passing the Comic Book Guy- then going up to 400- new desk again- to 500, then, finally, 600, where she was coasting evenly at about 625 pounds.

She was certainly a sight to behold.

The middle Simpson had become so large that she was no longer capable of walking long distances. For most things, she was now wedged somewhat comfortably in a mobility scooter, which Mr. Burns had provided to her hapless father as "a gift to a loyal employee" provided that they "not ask about the power source." Even with this, her great weight ensured that travel was slow, as her enormous yellow belly swelled down to the floor of the scooter and pooled around the steering column, some even oozing off the edge. Her fattened butt, too, wasn't well restrained, even by whatever overly-strained shorts she happened to be shoved into, as it, too, flubbed over the edge of the seat and pointed towards the floor. Her upper half, though not as impressive, was still rather large, with large breasts braless and just barely inside of some sadly overstretched T-Shirt- which was equally strained around her enormous arms- and, finally, three chins ringing a face floating in a sea of cheek fat. When she stood, which was not very common, her enormous stomach hung down to nearly ankle level, and made it difficult to walk- she could only manage about ten steps, even with assistance. The others at school had taken to teasing her even more, sometimes going so far as to poke her with sticks, pencils, rulers, and whatever else they had on hand; she was so fat, however, that nothing could be done, as her arms were too cumbersome to move at any speed and her fat so voluminous that there was no way to reach all of it. She ignored it, mostly, and snacked the pain away. Soon, though, she knew the chair would give- she could hear its groans even through her mass- and she knew, too, that if the chair were to go it was likely that she would never leave the house again, so large was she. She would keep growing, keep eating, until there was no way for her to move at all, and, from there, eat her last muscles away until she could not move her arms, could not breathe alone, and be entirely dependent on everyone else for the rest of her life.

She looked out, across the cafeteria where this had all began, at the destroyed remnants of fifteen or sixteen trays of lunch, and licked her lips.