EDIT: Just a heads up, this article contains calorie amounts, weights, descriptions of diets/exercise regimes etc. that some people might find triggering. Feel free to skip it!
The original article is pretty long so if you don't feel like reading that, the interview with TPP is much shorter and covers the main ideas anyway. In the article, Tara Parker-Pope talks about how when people lose weight through dieting, their hormones/body compositions/metabolisms essentially reprogram themselves to promote weight regain. I guess it's basically the same idea as starvation mode in EDs, where the body slows everything way down to sustain itself. After losing weight, people get obsessed with food, food starts tasting better, cravings get more powerful, and hormones kick in to fight the loss. Basically, the bodies of obese people make losing weight and keeping it off Very Hard to do.
There are a few interviews with people who had lost large amounts of weight and are now maintaining their new lower weights, despite biology and genetics working against them. The way they described their lives, though...well, it sounded like my life. Counting calories, tallying every last bite, working out compulsively, calculating cal intakes and burns obsessively. TPP discusses this as a necessary lifestyle change, the way people with epilepsy or high blood pressure or diabetes might follow highly regimented diets in order to control their illnesses. Another article criticizes this approach taken by formerly obese people because their mentality "resembles the symptoms of an eating disorder."
Since I've never been obese, I honestly can't attest to whether or not this hyper-vigilant approach to eating and exercise is truly the only way to prevent regaining the weight. It sure sounds a lot like an eating disorder, but of course I'm not suggesting that obese people have to "turn anorexic" to lose the weight and keep it off. It is interesting though that obesity carries such a stigma that illnesses like diabetes, hypertension, etc. don't. Plus, the treatment for obesity (constant vigilance in eating and exercise) also seems to carry some stigma, like people are supposed to stay slim and trim without working at it or thinking about it.
This also made me think of my dad, who was allegedly a chubby kid and teenager (although I've seen pictures, and he never looked that big to me) before losing a bunch of weight in college. To this day, he is religious about working out and eating right, and has maintained a slim weight throughout his entire adult life. To me, it seems insane that he would have to be so careful about how much he eats and exercises just to maintain his healthy weight, but maybe he does? My dad was never obese, so I'm not sure how much this applies to the ideas in the NYT article. Plus, he could probably gain a relatively significant amount of weight and still be healthy.
I'm also wondering if it works in reverse, like if a formerly underweight person has to eat more and exercise less to maintain a higher weight than someone who has always maintained that higher weight naturally. But now I'm just thinking through my keyboard, so I'll stop.