Weight-Loss Story: A Day in the Life of a Fat Cell
A talkative bit of blubber exposes the surprising ways we steer the body wrong.
Getty ImagesIt’s shortly after 10 a.m., and The Body—all 237 pounds of him—is in his cubicle, sifting through e-mails. I’m wedged next to his liver, sifting through the metabolic remains of his morning drink: Vitaminwater. It calls itself a “nutrient enhanced” beverage, a nutritious cocktail. Ha! It’s mostly sugar in a bottle, and I love it. It sneaks past the digestive system and lands in the liver, which converts it to fat and sends it straight to me. What a bonanza!
It’s a great time for me and my brethren fat cells. After millennia of toeing the line and giving up our stores whenever the muscles and nerves called on us, we’re now taking over. You don’t have to take my word for it. You can see it on the streets every day. More than 35 percent of adult Americans are obese. Not just overweight—obese. Cardiovascular disease? Type 2 diabetes? Cancer? Not my problem. I’m livin’ large.
By 11 a.m.,The Body’s starving. That muffin he had for breakfast provided plenty of calories, but they don’t satisfy him the way they used to. See, it’s my job to send a hormone signal—called leptin—to the brain so it makes The Body feel full. It used to work like a charm. But these days, I pump leptin like it’s a Middle Eastern oil well, and it just floats around in the bloodstream, aimless. With all that excess insulin swirling around to help The Body sop up his extra sugar intake, the brain doesn’t receive my usual leptin signal and issue the “you’re stuffed, stop eating” message. So he’s more apt to feel hungry soon after he finishes eating.
Life is sweet—saccharine, really. But it wasn’t always. I remember 40 years ago (The Body was barely a teenager) when I was born along with many of my fatty friends (puberty, the school nurse called it, which is when most adult fat cells should finish forming). I’d wait all day for some spare fatty acids I could store. Back then, most of the nutrition got used up. We fat cells would swell slightly, then shrink again. Those were lean times.
But I’m not going anywhere. I mean that literally. Fat cells never disappear. We’re virtually indestructible. The Body can deprive me of the greasy good stuff, and I’ll wither—but when he hits the drive-through again, I’ll rebound faster than he can say “Supersize me!” In a normal body, fat cells are mostly done forming after puberty. But if you’re obese, your fat cells plump up so much that new ones can be created. And lately, my neighborhood’s been getting a little crowded. Every time a fellow fat cell fills up and hits its maximum storage capacity, a new fat cell pops up next door. I’ve heard that a normal body has around 40 billion fat cells, but The Body rolls deep—in here, there are 80 billion just like me!
I’m pretty lucky. Back when The Body went off to college, he developed a soda habit. At almost every lunch, he’d knock one back. It was a special treat, and I’d snag a few fat droplets from the liver each time and store them up. He liked the caffeine, too, the pep it gave him in the afternoon. Soon enough, after The Body graduated and found a job, he needed another can of soda just to push through the midafternoon slump. That was the start of my glory years.
Nephron via Wikimedia CommonsHear that? The Body’s opening a can of soda as he digs in to his low-fat microwave lasagna. He’s trying to cut back, shed a few pounds—and hey, if you’re trying to lose weight, it makes sense to eat less fat. But have you ever tried lasagna without butter or oil? Tastes like cardboard. So there’s extra salt and sugar to compensate, and it’s still easy for me to convert some of that sugar to fat and squirrel it away. He has no idea!
The poor sap. Back in college, when The Body skied or cycled almost every weekend, his weight was under control. His diet had a lot less sugar, and his brain listened to my leptin warnings, quashing his hunger whenever I managed to plump up. I’d get a little ahead after a big weekend of beer and wings, inflate a tad. Then the next day he’d eat a bagel and apple for breakfast and jump on his bike. His muscles burned up all the handy glucose, and I’d be forced to break down some of my precious self into fatty acids and glycerol. I’d give glycerol to the liver, which would convert it into glucose to burn, and the fatty acids would go straight to the muscles for energy. I’d deflate and hunker down, waiting for his next binge.
Now he polishes off the lasagna tray in six bites and swivels back to his computer, clicking and clacking through the afternoon. When he heaves himself from his chair to head home at 5 p.m., it’s the hardest his heart has had to work all day. I’m not worried, though—there’s plenty of fuel in his muscles to provide energy, so I never have to offer up any of myself to help. I’m lying low, laughing, confident I’ll never be called on to liquidate my stash.
I get to relax during the hour-long commute home. What will I have for dinner tonight? Fried chicken? Burgers? But when The Body sags into his chair at the dinner table, he sees grilled chicken and salad. Lettuce, tomatoes, peppers… and what the heck is that, toasted pine nuts?! Oil-and-vinegar dressing, not even creamy ranch. Unfortunately, the salad’s fiber slows his digestion of the sugary dinner roll he snags from the basket. What gives? he asks. We’re eating healthy, says his wife. No more junk for dinner.
This could be bad for me, but I know The Body, and true to form, he cracks a beer. Sweet relief! I can score fat out of a beer as well as a can of soda. The ethanol it contains is a derivative of sugar, so some of the boozy goodness goes through the liver and converts to fat. After dinner, he takes the dog out for a walk. Thankfully, a casual stroll won’t exert enough energy to dip into my storage. Even better, when he gets home, he plops down to watch the game. Conditioned to snack at night, he grabs a Rice Krispies square, a tiny sugar boost for me. He slides into bed around midnight, hoping for his usual six hours of sleep. While The Body snoozes, I get to relax too. He doesn’t rely on my stores during the middle of the night, so I’m waiting for morning and already pulsating. I know his lack of sleep will make him stressed, hungry, and more likely to crave sugary, high-carb foods. Mmm, maybe doughnuts for breakfast?