Fun With Genetics

So I've always had a fascination with the genetic side of obesity and weight gain. All the factors that are outside your control, such as who your parents are, your family background, your geographic origins, and even minor things like whether your mother was a smoker can all go into how you wind up as an adult. And we're fast approaching an age where we can easily toy with these factors to be the human we want to be.

That said, the last time I actually looked hard at the science of weight and genetics was a decade ago, and as with so many functions of the human body, recent discoveries show that there's no single "fat gene". As with most genetic things, it's an incredibly complex interaction between dozens or even hundreds of genes, and we're probably decades away from any sort of gene therapy that could help with weight gain or loss. 

And of course, there are plenty of folks who aren't born fat or have any genetic history of obesity, but still manage to get there anyway. 

This is all to say that there's very little accurate science in the story below, and you should just look at it as sci-fi smut :P Enjoy!

"Thanks for agreeing to be the test subject for my term paper, Rob. You're a real lifesaver."

"No prob," he said as he reached a hand around to scratch the back of his neck. "And uh, sorry about being kind of a jerk to you all through first year. I'm hoping this sort of makes it up to you."

Jean paused for just a moment as he recalled months of having his books knocked from his hands and his notes stolen just before exams. But then he shrugged and offered Rob as sincere a smile as he could. "If this all goes smoothly, consider it water under the bridge! Now, strip down and lay back on this chair--"

"Wait, strip down?"

"You don't want to be wearing clothes for this. Unless you don't care if your current garments get a few tears."

"Tears?"

"I told you this test will probably result in some expansion,” Jean explained, hiding his grin. “You said you were cool with that, right?"

"Y-yeah, just thought you meant that it'd be like getting stung by a bee or something."

"Something like that. But best not to take any chances.” Jean ordered: “Strip," and Rob complied.

“Including the boxers.”

Rob’s hands were already guarding his bulge, so his outburst came as little surprise to Jean. “No way man! What sort of experiment is this?”

Jean dismissed his concerns with a wave of his hand. “Fine fine, but don’t come crying to me when you go home commando.”

With Rob settled into the chair, Jean took note of the decently-sized lump in his groin. This time he did nothing to hide his nearly feral grin as he fastened restraints around Rob’s wrists and ankles, then turned to leave the room.

“Hey! What’s with the cuffs?”

“Purely for your own safety,” Jean lied. “Now, this room is going to be filled with a chrono field, so I’ll be in the neighboring office watching the whole thing on closed-circuit camera. We’ll be able to talk via microphones, so if something feels off, just let me know.”

“I dunno man, this already feels kind of ‘of’ to me…” Rob trailed off, but Jean ignored his concerns and left the room.

In his office, Jean hit several switches and pressed a few buttons, and in Rob’s room a robotic arm swung down and plunged a needle directly into Rob’s neck. Rob yelped in surprise and pain, then shouted obscenities along with demands for an explanation.

“That’s the nanobots, Rob. We’re going to be doing some genetic manipulation, and only nanobots are able to get down to the level of DNA to do some splicing.”

This explanation didn’t seem to mollify Rob, who began to struggle with the restraints. Jean ignored this as he brought up a monitor showing Rob’s vitals and his full genetic composition. A few keystrokes and Jean ordered the nanobots now coursing through Rob’s bloodstream to restrict his sugar levels. His struggling ceased almost immediately, followed by a low groan.

“What did you do?”

“Just made you a little calmer,” Jean replied. A few more keystrokes activated an algorithm that produced several chemicals and hormones that altered Rob’s mood from one of growing alarm to blissful acceptance of all things. It was a lot like an illegal street drug the name of which escaped Jean’s recall. Rob’s groans went from anguished to relaxed, and then almost aroused.

Well, that wasn’t supposed to happen, but I guess we’ll roll with it, thought Jean as he watched Rob pitch an increasingly impressive tent.

Jean clicked the mic. “How you feeling in there, Rob?”

“Pretty good, actually,” he replied with a giggle.

“Great, we’re going to start now with a few minor tweaks,” replied Jean. Then, almost as an afterthought,  “Lemme know how you feel.”

Rob just giggled again in response.

Alright, let’s fuck this guy up. Jean brought up a number of different screens detailing various aspects of Rob’s genetic makeup. Here, he could do whatever he wanted with him. A few clicks here and Rob could be born of Asian descent. A few more clicks would give him curly hair, green eyes, and enough body hair to put a werewolf to shame. There were even a few nascent genes that could give him a sixth finger or a third nipple, although those weren’t really what Jean was after.

No. For this tale of revenge, Jean wanted to ruin Rob’s perfect jock body. A lifetime of cardio and regular visits to the gym was about to come to a screeching halt, and thanks to the chrono field, were even going to be erased from history. It would be like he’d never jogged a day in his life.

The effects were dramatic. Rob’s carefully cultivated physique simply faded away, his hard-earned vasculature shrinking back as a rising tide of flesh seemed to consume every visible muscle group. Soon he was just an average guy, with no visible pecs, abs, or quads. His chiseled jaw rounded out, his broad chest and shoulders withered, and his middle rounded out into the lazy gut that most men develop in their middle years.

“That felt weird…” Rob moaned, still curiously erect. Although the rest of him had decayed, his cock seemed to have lost none of its potency, towering above his groin behind boxers that barely contained either it or Rob’s somewhat expanded ass.

“That’s normal,” Jean casually replied, deciding to use that erection as a measure of Rob’s next changes. Getting into the genes that governed familial history, Jean altered chromosomes granted by his mother to reflect the fact she had always been quite a heft lady rather than the relatively petite woman she actually was. Like mother like son, as they say, and there’s nowhere this adage remains more true than your waistline.

As before, the chrono field meant the changes to Rob’s genetic history was reflected immediately. His entire body seemed to rise like dough. Arms, legs, stomach, chest, face--all of it grew a distinct layer of puppy fat in moments, giving Rob a much more appealing cherubic look than the wasted form he’d had before.

It also began his descent into obesity in earnest. Already the mound of fat on his stomach had become fairly pronounced, with the latest layer adding a softness that jiggled with every tiny movement. It also began straining his boxers, with new lovehandles pooling over the waistband in a pronounced muffin top.

“Now it… kinda hurts…” Rob mumbled while opening and closing his jaw several times--obviously unused to the additional weight that adorned his cheeks and new double chin.

“I told you to strip. Now you’re just going to have to wait for the next bit,” Jean said with a few more keystrokes. “Hopefully.”

Next, Jean went back further, altering his entire family line to be predisposed to bulk. A few clicks added literal tons to Rob’s family tree and generational adaptations to carrying heavy loads. The shoulders and chest that had so recently shrunk now widened past their original width, but they were soon eclipsed by Rob’s waist and hips. Through the microphone, Jean heard Rob’s bones make terrible cracking sounds as his skeleton expanded, but they weren’t nearly as loud as his boxers finally being sheared in half.

“Aw, yeah, that feels SO much better,” Rob groaned, his growing bulk now free to expand on the chair, and his hard cock swinging freely in the air--perhaps an inch shorter now thanks to the fat collecting around his groin.

Jean took stock of what he’d wrought so far on Rob. He was certainly obese by medical standards, but he looked… sturdy somehow. A quick glance at several ancillary screens revealed that much of the musculature Jean had removed earlier had returned but with a far different composition. He’d gone from lean muscle to well-marbled beef, especially in his legs and hindquarters. Generations of hauling a heavy load meant a build capable of doing just that.

It hadn’t come without cost, of course. Now if Rob were to devote the remainder of his life to diet and fitness, he’d never have a six-pack again, and even the slightest glance at refined carbs would cause him to pile on the pounds. Merely staying under 300 pounds would be a constant struggle.

And one that he’ll definitely lose with this next alteration.

Now looking at the genetic markers set in Rob’s own life, specifically his childhood and puberty years, Jean changed them to indicate an early life that wanted for nothing when it came to calories. Genetic markers set by parents that kept Rob from eating whatever he wanted were replaced by less attentive guardians that allowed him to consume whatever sugary snacks he liked.

The final keystroke pressed, and the puppy fat that had given Rob’s broad form a well-rounded look billowed outwards, expanding in all directions. Thick fingers became sausage-like digits, ankles swelled with adipose, and his middle surged upwards as loosely defined pecs swelled into a pair of heavy breasts.

There’d be no mistaking Rob for anything but a lifelong fatty now. His entire body was covered in a thick layer of adipose that blurred his anatomy until it all seemed like one giant blob. His neck had disappeared under his thick jowls and bulky shoulders. His armpits had filled in with flab and now kept his limbs out at an angle. Elbows and knees were hardly even the faintest bumps. His most defining physical feature had become the crease that circumnavigated his middle, delineating where his enormous belly folded over his groin. It was so big that, much like his armpits, it was shoving his erection aside at an angle. Or at least what was left of it, Jean noted with a mischievous grin.

Jean checked the secondary screen and noted Rob’s weight had doubled since he’d gotten into the chair to 360 pounds. He’d forever crave food and would find snacking between meals as normal as breathing. He’d probably put on another 30 or 40 pounds all on his own without a lifetime of memories teaching him to clamp down on those snacking habits. Or maybe he’d have never learned, Jean mused. Even with modern probability analysis, a human was still too complex to fully model from birth to adulthood. We could only make some educated guesses--and maybe place our thumbs on the scales a bit.

Jean looked at Rob’s wide face and his goofy smile and considered whether he’d suffered enough. Or at least, would suffer when he’d removed the nanobots and brought his brain chemistry back to normal. Would the shock of seeing himself this large be enough to ruin him utterly?

He pondered as he watched Rob wobble his ponderous belly with a few slight gyrations, the oblivious goof giggling as his stomach rocked back and form just out of time with his movements. Then Rob picked up speed enough to cause his half-buried cock to slap against his belly, a light smear of pre-cum coating his lower extremities. It seemed like he was genuinely enjoying himself.

Well, if he likes 360 pounds, I’m sure we can find ways to add a few more…

Jean decided to pull out all the stops. Hormone levels, thyroid, metabolism--he started adjusting all of it, hurdling Rob headlong into hyper obesity. He watched as the numbers next to Rob’s image kept getting higher and higher, Rob’s giggling coming through the microphone as his addled mind continued to view his rapid inflation as a sensual plaything rather than the complete destruction of his life.

For a time, Rob merely expanded larger and larger as the pounds piled on. Then Jean noted contours and features appear on Rob’s topography. Whereas before he’d been merely an almost amorphous mass with nipples, a belly, and a dick, Jean saw previously undefined joints gain wrinkles and creases where the fat simply couldn’t accumulate without hindering Rob’s movement. The pillows of lard stuffed in his armpits suddenly gained a crease that surrounded his upper torso and further defined his now pendulous breasts. His stomach seemed to fold upon itself as the mass near the bottom outgrew the smaller protrusion on top. And his tube-like limbs suddenly gained a very different sort of definition as the bulk accumulated mostly on and over the far-buried musculature.

The end result was a man that was comically large. Jean nearly burst out laughing when he looked at the camera view to see Rob’s blubbery form. He was so enormous that constant snacking would be necessary just to maintain his weight--at least, had Jean not modified his metabolism. Now, Rob would probably never lose a pound even if he tried.

Jean wondered if he’d maybe overdone it. What if Rob couldn’t even stand on his own two feet? How would he bathe himself? Would sex even be possible with that nub sticking out of the pillowy lard that defined the area between his legs and his sagging stomach?

Then, with a shuddering lurch, Rob ejaculated. It came as a complete surprise to Jean, who had simply thought Rob’s jiggling simply a natural byproduct of his morbid obesity. It turns out he’d been greatly enjoying the friction his hundreds of pounds afforded him. It seemed not being able to reach his own dick may not be as much of an obstacle to his own gratification as Jean initially thought.

Ugh, and it was quite the load. Jean looked around the small office for some paper towels, then decided it wasn’t worth the effort. He’d need a mop at least.

Jean was surprised at himself. He’d achieved his revenge, and yet he was still annoyed at the massive blob who’d just blown his load and was now comfortably snoring in his post-coital bliss. Jean angrily reduced chemicals keeping Rob happy and compliant and then administered some drugs to remove his memories of the past 30 minutes. He’d have to satisfy himself with camera footage of the horror Rob would surely express upon waking up.

Jean closed down the systems he’d used and gathered his things to leave. But before he went, he returned to Rob’s unconscious form and gave his stomach an impressively loud slap. The impact not only woke him but also sent ripples flowing across his expansive body. Five steps later, Jean was smirking as he heard the first of what he assumed would be many howls of anguish.