Twilight's Weight Gain Experiment

by Shamrock95


Twilight's Weight Gain Experiment

Spike held a steaming mug of coffee in one of his claws, as the other reached out to turn the doorknob of Twilight's room. With a click, the door opened and Spike entered. At the other end of the room, hunched over a desk, Twilight sat amid a pile of papers, a quill scribbling on one as she muttered to herself.

"Here you are, Twilight." Twilight started slightly as Spike set the mug down next to him.

"Oh, thank you, Spike," she said hurriedly, her eyes not leaving the paper before her.

"You look a bit preoccupied," Spike noted, peeking over her shoulder. "You've been in here for a few hours, now. What's got you so interested?"

"Well..." Twilight set down her quill and chewed her lip thoughtfully. "Well, it's about Shining Armour. He came to visit me yesterday, you know. I mean, I know you were at Rarity's for the duration, but... you should have seen him."

"What do you mean?" Spike asked. In response, Twilight's horn glowed as she plucked out a photograph from the stack of paper next to her, levitating it over to Spike. Spike took it in his claws and took a look, before his eyes widened at the sight of the big fat blob of a stallion before him. His eyes ran over Shining's bulging belly, his flabby neck and cheeks, his widened forelegs.

"Wow," Spike muttered, swallowing. "He, um... he certainly filled out."

"I know," Twilight nodded. "Took me completely by surprise. Not only has he put on a ton of weight, his appetite has increased exponentially, too. We went to Hay Burger after I met him at the station, and he put away two families' worth of food like it was nothing!"

"Seriously?" Spike said, whistling.

"Seriously," Twilight replied. "And that's not even the strangest part. The strangest part is... well, he seemed to enjoy it. He actually liked being that fat."

"Wait, what?" Spike took another look at the photo. Sure enough, Shining was smiling widely, two large dimples forming in his plump cheeks. "He likes being a fatass like that?"

"That's my brother you're talking about," Twilight warned.

"Sorry," Spike replied. "So, is that what all of this..." He pointed at the stack of papers. "...is about?"

"Precisely," Twilight nodded. "As you know, our society puts a lot of emphasis on being thin and healthy. We see it in advertising and media, our foals are taught about it in school, and there's increasing talk of the obesity epidemic hitting Equestria. Being overweight or obese is almost universally seen as a problem that needs to be corrected. And yet, Shining is morbidly obese here and actually smiling about it. Heck, he was downright proud of it! And I intend to find out why." She produced a sheet of paper from the pile, with a graph drawn on it above several lines of scribbled notes. "My hypothesis is that an increased intake of food is linked to increased production of endorphins in the brain, hence the concept of comfort eating. If my hypothesis is correct, and assuming that endorphin rushes are as addictive as they're made out to be by exercise enthusiasts and extreme stunt ponies, then that would explain why Shining is so happy. He may not enjoy the weight at all—he may just enjoy eating. And if that's the case, then he could potentially lose weight while still-"

"Twilight," Spike interrupted. "Where are you going with this?"

Twilight smiled widely. "Science, Spike. Science is where I'm going with this. Tomorrow, I plan to run a little experiment, and I might need your help with it."

"Experiment?" Spike repeated, arching an eyebrow. "What kind of experiment?"

"Eh..." Twilight yawned. "We'll talk more about that tomorrow. Right now, it's..." She glanced at the clock on the wall, and her eyes widened. "Goodness, it's ten to twelve. I'd better get to bed... and so had you, come to think of it."

"Alright, then," Spike shrugged. "G'night, Twilight."

Spike turned and left, while Twilight worked on neatly shuffling her papers into alphabetical order. She exhaled slowly through her teeth.

"Alrighty, then," she told herself. "Tomorrow, we're gonna science this conundrum up."


The following afternoon, Twilight sat on a sofa in her room, busily scribbling away in a notepad.

"Experiment log," she wrote. "The purpose of this experiment is to determine just what it is that Shining Armour enjoys about being fat and overeating. In order to determine this, I plan to gain some weight of my own, through a combination of overeating and a weight gain enchantment (see enchantment log 773-D for further info). The experiment will last for a total of one (1) day, after which, I should hopefully have some clearer insight into this. My hypothesis is that eating large enough quantities of food stimulates the pleasure receptors in the brain. No word on how being overweight could be considered enjoyable yet. Results to follow."

Closing the notebook and setting it down on her desk, Twilight stretched out on the couch and hummed tunelessly to herself as she waited for Spike to come and give her the go-ahead for the experiment. She glanced at the clock. "Should be ready any minute now..." she murmured.

Sure enough, a couple of minutes later, the door creaked open and Spike stood there, bearing a look of world-weariness that Twilight hadn't seen since the Smarty Pants fiasco a few years ago.

"I just want it on record as saying, I think this is a mistake," he said flatly.

Twilight immediately picked up her notebook and began writing, before closing it again. "Noted," she said cheerfully.

"Twilight, I was being..." Spike shook his head. "Never mind. Is your, um, 'experiment'..." He made air quotes with his claws. "...ready to go?"

"Sure is!" Twilight said happily, clopping her hooves together as she got up. "This ought to be a fascinating experiment. Okay, step one..." She pursed her lips. "Step one is the weight gain enchantment. Now, where did I put it... aha!" She triumphantly plucked out a scroll from her desk. "This spell should make me gain about a hundred pounds pretty much instantly."

"Eh?" Spike blinked.

"This is the weight gain enchantment," Twilight explained. "I read up on it last night."

"Wait, did you say a hundred pounds?"

"Yes, a hundred pounds," Twilight said impatiently. "I need to be put in at least the 'obese' category if I want to get a feel for how Shining feels, but at the same time I don't want to overdo it." She pored over the scroll one more time. "Alright, that all looks in order. Okay, Spike, stand back."

"Please don't explode," Spike muttered, as he backed off into a corner of the room.

Twilight screwed up her eyes in concentration, as her horn began to glow a bright purple. Strands of lavender magic drifted out from her horn, coming together to form a kind of wispy magical cloud. More strands came out and joined the cloud, causing it to grow until it was about the size of a football. Once it had reached that size, the cloud drifted up into the air, before rushing down and absorbing itself into Twilight's body.

"Wh... whoa!" Twilight gasped, as she felt her sides immediately begin to swell up and soften. The spell worked fast, causing her to bulk up at an astonishing rate. In less than three seconds, her stomach had ballooned out into a fine-sized gut, hanging down low enough to dangle just above the floor at its lowest point. Her rump and thighs also began to swell, her cutie marks blowing up in size as little dimples of cellulite began to appear on the back of her thighs. Her cheeks both swelled up, too, at the same moment a ring of adipose formed around her neck. In just under five seconds, Twilight had gone from a rather skinny filly to a properly plump pony.

"Well... that worked," Twilight said slowly, extending a foreleg out as she studied the fold of fat above her hoof. "That feels, oof... yeah, that feels heavy."

"Whoa." Spike blinked a couple of times as he took in the sight of Twilight's love handles. He smirked. "Heh, I guess we'll have to call you Twilard Sparkle now, huh?"

"You know, Spike," Twilight said sweetly, "it'd be a real shame if the town found out about those poems you've been writing."

Spike blushed deeply. "I'll be good."

"Good. Now, then..." Twilight poked at her distended belly with a hoof, watching as it wobbled at her touch. "Hmm... soft. Definitely soft, and sort of... squishy? I guess?" She levitated over her notebook and scribbled a couple of lines in it. "Yes, soft and squishy is how I'd describe that. It feels... not too unpleasant, actually. Sort of warm and soft, kind of like being covered in pillows." She nodded gravely, her mind in full scientific analysis mode. "Yes, not unpleasant at all. So, I guess that's one thing we can chalk up—fat is nice to the touch." She made a note as such in her notebook. "Alright, next test—mobility."

Grunting, Twilight raised a foreleg and placed it firmly on the ground before her, before doing the same with the other foreleg. Her hefty hind legs followed suit, and she began to move around the room at a slow but steady pace, with a noticeable waddling gait, her fat bouncing and wobbling as she went. It wasn't long before Twilight was beginning to sweat and pant for breath, her face flushed slightly red from exertion.

"Sweet Celestia," she gasped. "How strong must Shining be to lug all that weight around?" Breathing heavily and leaning against a wall, she made yet another note. "Movement quite severely restricted, not at all what I observed with Shining. Must be some correlation between muscle mass and mobility."

"Are... are you okay, Twilight?" Spike asked, a note of concern in his voice.

"'m fine," Twilight panted. "Hoo, boy... Okay, the third and final test... the eating test."

"Eating test?" Spike repeated.

"Yeah, to see what Shining enjoys so much about stuffing his face. Come on, we're going to Sugarcube Corner."

"Do I have to watch?" Spike grumbled, as he followed her out of the room.

"Yes, actually, you do," Twilight replied. "I need you there to make observations."

"And perform the Heimlich manoeuvre if it comes down to it?" Spike snarked.

"Very funny, Spike," Twilight shot back.


"Too dee do be do..." Pinkie Pie hummed to herself as she tapped her hooves on the floor behind the counter of Sugarcube Corner. It had been a slow afternoon so far, and so her ears pricked up pretty high when she heard the door opening.

"Hello!" she called out cheerfully. "And welcome to Sugarcube... whoa."

That was a pretty apt descriptor of Pinkie's state of mind as Twilight lumbered up to the counter, with Spike not too far behind.

"Hey, Pinkie," Twilight said casually.

"Um... hi, Twilight," Pinkie replied, eyes wide. "What's with the big caboose, all of a sudden?"

Twilight flushed as Spike shoved a fist into his mouth to stifle his laughter. "It's part of an experiment. It's purely for science, trust me."

"Okay... so, what can I do for you?" Pinkie asked.

"I'm gonna need you to bring me..." Twilight gazed up at the menu. "...an apple pie, a large cheesecake, a platter of cookies, a bowl of chocolate fudge ice cream, and a tray of assorted doughnuts."

"And an ambulance on standby," Spike quipped.

"Spike, enough," Twilight snapped. "Can you do that, Pinkie?"

"Sure can!" Pinkie saluted. "Just take a seat and I'll bring it to you. For science!" she exclaimed.

Twilight laughed. "For science!" she echoed.

Sure enough, Twilight soon found herself seated at a booth, her new gut pressing into the table and forming a crease above and below it. Before her was enough sweets to feed the entirety of Ponyville Elementary.

"Alright then," she smiled, licking her lips. "Let's go!"

And with that, she dug in. Immediately, she found herself appreciating the sheer feeling of liberation she had granted herself. Not only did she get to eat all this delicious sweet stuff, she even had a genuine good reason for doing so!

"Mmm, so good," she moaned, as she munched her way through a tray of cookies. She flipped open her notebook and began writing. "Starting to feel effects of hyperactivity, a.k.a a sugar rush. Definite signs of pleasure receptors being stimulated in the brain—warm, fuzzy feeling." She giggled. "Now we know why it's called comfort food, huh, Spike?"

"I guess..." Spike shrugged, watching with folded arms as his surrogate sister stuffed her face with pie.

"Ahh, that's good pie. Bramley apples, I take it?" she called to Pinkie.

"Golden Noble!" Pinkie called back.

"What's that?" A middle-aged golden stallion raised his head from his newspaper.

"No no, we use Golden Noble apples," Pinkie clarified.

"Oh, I see."

Twilight returned to her feasting with gusto, but soon found herself slowing down.

"What?" she mumbled. "Ugh... this can't be right. I'm starting to feel full and I'm not even a fifth of the way through."

"Gee, who'd have guessed?" Spike deadpanned. "You only ate enough to feed a family of three."

Twilight pressed on valiantly, finishing off the cookies and ice cream and making her way through the pie as best she could. Sadly, with just over a quarter of the pie gone, she had to concede defeat.

"Ooooh..." Twilight lay slumped over the table, her stomach gurgling and churning fiercely, her face covered in crumbs and contorted with pain. With what little strength she had, she levitated her notebook up one more time. "Extra weight... does not appear... to grant... increased appetite or... stomach capacity. Requires further... ugh... investigation..." She gasped. "Oh Celestia, I don't feel so good..."

"Twilight?" Spike asked. "Are you..."

Twilight's eyes widened, and she began to make a series of retching sounds.

"Oh, horseapples," Spike and Pinkie said in unison.


"Gross overeating," Doctor Stable concluded, as he held a stethoscope to Twilight's belly. "Quite painful, but nothing some good antacids won't fix. But really, your highness, try to limit yourself to more sensible portions in future."

"Thanks, Doctor," Twilight replied, still rather pale. Once Doctor Stable left the surgery to get her prescription, Spike turned to her.

"So, what's the conclusion?" he asked.

"Well, apart from that... incident..." Twilight shuddered. "I have to say, it wasn't too bad. My hypotheses were correct in both regards—being overweight feels physically pleasurable, and so does stuffing your face with junk... for a while, anyway." She laughed hollowly.

"So, what now?" Spike asked.

"Now," Twilight said, "we go home, I get this weight off, and I avoid sweets for a long, long time. But you know something?" She smiled. "I'll keep that weight gain enchantment handy. I wouldn't mind using it again sometime..."

END