Just as I was about to power down my computer, the message zipped into my inbox: "You don't have to be obese, Laura. It's really not even hard. It just takes commitment." As a writer who has published very explicitly about my lifelong struggle to accept, and embrace, my 250+ pound body, I get these kinds of emails regularly. The unseen authors, possessed of a singular fervor, insist that I can't be healthy if I'm fat.

At one point, my instinct was to deliver a thunderous clapback explaining that, according to actual research, size isn't an indicator of health; to righteously school them with the doctrine of Health at Every Size, or rub their noses in the truth that I have walked 5ks as a fatty. However, I am increasingly uncomfortable with this line of defense. In fact, I'm tired of proving my dignity and self-worth by offering my blood pressure on a silver platter. Yes, as I've gotten older, recovered from a catastrophic injury, subsisted on the full-time freelancer's diet of frozen foods because of time and budget crunches, my physical health has declined. But I realize now that my body shouldn't need defending on any grounds.

Our cultural attitudes toward fitness have moved beyond the Jazzercized hard-body as the ultimate prize in-and-of-itself; that hard-body is now the conduit to a clean-eating purity of spirit. The ad copy for Shakeology, a protein shake, sums up this outlook succinctly: "You'll not only be healthier, you'll feel healthier — and happier — who doesn't want that?"

As it turns out, me.

Or at least, I don't want my BMI to be the calculus of my personal virtue. Of course, it's difficult, given that the medical establishment is notorious for making weight-loss the total cure-all (I once had a doctor lecture me about bariatric surgery during a consult for a sinus infection). As activist Virgie Tovar puts it, "There is incredible cultural impetus to be 'healthy' and 'health' is framed … as a personal/individual responsibility."

Movements like Health at Every Size and the myriad of "fit fatties" groups across social media offer a language of resistance against this kind of size-based stigma by arguing that big guys and gals can still have perfect blood pressure. Still, this rhetoric around "fit and fat" privileges health and wellness as a barometer of an individual's worth, and it celebrates what activists like Stacy Bias call "the good fatty": "They're fat but they engage in none of the typical behaviors assigned to fat people," Bias writes. "They mostly only eat healthy foods. They are fitness fanatics … Their bodies are strong and able … the poster fatties for Health at Every Size because they hold up under scrutiny."

Years ago, I would have been one of those "good fatties" who held up under scrutiny. I'd spent my teens and early 20s in a cyclone of binging and purging; when I finally emerged, storm-battered but grateful to be alive, I vowed that I would accept my fat body. Though I tossed out the scale, I found myself unconsciously, and very publicly, performing certain rituals of fitness — neurotically checking my Fitbit to make sure every walk was a 5k; stocking my fridge with organic vegetables (though I never did much like baby carrots); and using my blood pressure as a talisman against the haters stampeding into my inbox. I felt the need to justify my fatness, my existence, to the rest of the world.

Then, one terrible February morning, I slipped on a patch of ice, breaking one ankle, and spraining my other one (a category three, or granddaddy of sprains). For two months, I was completely bed-bound. The rest of that year was a thick slog of physical therapy and weaning off my cane; walking even the shortest distances brutally winded me. I was the good fatty no more — but during that time spent on the sofa, eating frozen and fast food, I became someone different, someone who was more in touch with herself: Once I lost the standard trappings of health, my focus shifted from my body to my work, and in joyful rush of productivity, I finished the first draft of a novel. My evening walks got shorter, and not just because of the physical pain — after working my 9-to-5, I'd come home eager to revise a scene or pitch out essays; my mind became the part of me that craved exercise. Dinner became whatever I could stick in the microwave — and, given that I was still paying doctor's bills, whatever I could stick in the microwave had to be cheap.

As my byline expanded, so did my waistline. Remarkably enough, I didn't care. Not even when, at a community picnic, one of my neighbors ruefully remarked, "Honey, I used to see you walking all the time." She didn't see me alone in my apartment, writing until dawn, before heading off to an office, so I could finish that chapter, fulfill that assignment. She didn't see me come to the quiet conclusion that I could make a go of full-time freelancing (at least for a while). For Ragen Chastain, a fat activist, athlete, and health coach, one of the more troublesome parts of the good fatty dynamic is the kind of moral prerogative it can represent: "Participating in fitness/athletics is no more or less virtuous than knitting a tea cozy. Running a marathon is no better or worse than watching a Netflix marathon." Being the good fatty, the woman who makes a conspicuous consumption of baby carrots when she really wants Nutella, is like putting on the same straightjacket I wore when I was breaking myself in fruitless pursuit of some immaculate thinness that was going to make me happier, healthier, more whole.

Our culture's fixation on a very particular type of health and wellness — the metrics of which can only be gauged by BMI or blood pressure or the number of steps and miles — isn't just reductive, it excludes broad swathes of people, particularly disabled and low-income people from the moral worthiness that health supposedly confers. A recent New York Times piece laments the volume of sugary drinks and sodas purchased by food stamp program participants, but this hand-wringing never touches on the hard grind of poverty, where those sugary drinks are a pick-me-up between long shifts, or Heaven forbid, simply a sip of something that tastes good. The all-abiding need to be healthy overrides personal choice.

Of course, there are people of all sizes who genuinely want to run marathons; who care about their blood glucose; and who can afford a fridge full of organic food, and like to cook. And that is perfectly okay — just as it is perfectly okay for my idea of a great night to be making my literary agent's novel edits while eating thick spoonfuls of Nutella for dinner. And not everyone who can't — or doesn't want to — embrace society's very specific definitions of health is necessarily a "bad fatty" like I am. That personal virtue doesn't reside in BMI or blood pressure. Indeed, that takes commitment.