If there ever was a sober voice in this world’s considerable madness around weight loss, it’s the National Weight Control Registry. Based in Rhode Island, it tracks more than 10,000 people who’ve been keeping an average of 70 pounds off for more than 6 years, and its purpose is to learn what helps these people keep it off.

It is true that much of the commercial weight-loss industry is composed of charlatans who lack evidence to back up their come-ons. But that's not the same as saying that there is no way to reduce one's body size sustainably.

As you know, I did (am doing) it, and I have lots of friends who have as well. But there's also the long-term, legitimate, National Weight Control Registry, which is coming up on 20 years and tracks more than 10,000 people who've lost significant weight and kept it off for significant time.