An article on Monday, May 2^nd in the New York Times by Gina Kolata about “The Biggest Loser” contestants who are struggling six years later with regaining much of the weight they lost on the show drew a flood of responses from New York Times readers. The article — “After ‘The Biggest Loser,’ Their Bodies Fought to Regain Weight” (May 2, 2016)— explained how the body fights back hard against major weight loss, with changes both to how many calories a person burns when at rest, and levels of some hormones. Readers posted more than 2,500 comments and the article was the most shared on The Times website and Facebook page on Tuesday. This got me to thinking, why can’t we keep it off?

To me, the most daunting challenge facing dieters isn’t weight loss. Nearly all dieters lose some weight no matter what program they follow. The problem is that most dieters don’t know how to keep the weight off. In recent years, research has focused on unlocking the complex biological processes that might help explain why dieters have little trouble losing weight but struggle to keep it off. The researchers in the New York Times article address how metabolism shifts as we lose weight. A newly thin body needs 8 to 10 fewer calories per day for each pound of weight that’s been lost. A girl who loses 30 pounds requires about 240 to 300 fewer calories each day than she did before the weight started disappearing. And don’t forget your hormones; they can play havoc with our weight and waistline. Some studies show that after a weight loss, levels of the appetite-regulating hormone leptin drop, making it harder for us to control our cravings, especially for our favorite “bad boyfriend” foods. (Haven’t heard of “Bad Boyfriend” foods? Just click here to buy The Skinny Jeans Diet book.

These are interesting findings, and from a strictly scientific point of view they make perfect sense. But what the scientists are missing is the uniquely human element of weight loss. Dieting is a pain-motivated behavior. No one goes on a diet because they’re happy. They’re in pain- about being ridiculed, about feeling worthless and ashamed, about feeling out of control, and about not fitting into their favorite clothes. Since the pain of being overweight can be almost unbearable, most dieters will do anything to get thin. I see 30 clients a week on average, and I can say that almost all come into my office because they’re in this kind of pain and will do anything to get rid of it.

But once the weight comes off and the pain passes, they forget. They start canceling appointments, they stop following my tricks and tips, and they don’t think about their bad boyfriend foods. This is normal. Our minds are designed to move us past the memories of unpleasant experiences. However, when we lose our vigilance, we gain the weight back. This is the biggest problem for dieters- the dieters in my office and the dieters from The Biggest Loser.

Every day millions of dieters in this country lose weight. But nearly all of them gain it back- as the Biggest Loser study showed. This is why I tell my clients that losing weight is a big booby prize. People who lose weight think they’ve crossed the finish line. But losing weight isn’t like running a 10K race. There may be a finish line to weight loss, but there’s no finish line to weight management. It’s an ongoing, lifelong process. And yes, it requires constant vigilance.