My uncle, who stood out like a sore thumb in Britain, weighed over 400 lbs by age 40. Growing up I always remembered him as an exceptionally overweight man.
Then at age 40 he decided to do something with his life. He lost 250 lbs just through dieting alone (he didn't start exercising until he was far skinnier). Today at age 55 he's stick thin and runs in marathons regularly, and he's stayed that way for the past 15 years.
My uncle is proof that NY Times article is complete nonsense. If people work hard enough, they can permanently change their bodies.
What I do agree with is that when people get to their target weight, they tend to revert right back to their old eating habits. That's why The Biggest Loser contestants have their weight shoot right back up. If you want to truly change your body forever you have to radically and irreversibly change the way you approach food. That's the key to a successful diet, not a target weight.