Of course, Brooker has also had some failures, men who dropped out because they found themselves unable to go along with the program. Whenever he mentions them, which he does frequently, I’m moved to consider my own success and what seemed likely, in the beginning, to get in my way: Brooker’s theories.

He’s a motivational speaker, one of many who offer to help people realize their better selves. At the start of every meeting, he’s introduced by one of the members as “our leader” or “our guide.” He delivers his advice with the passionate vehemence of an evangelical preacher. The word “brainwashing” has been spoken now and then in the meetings. He announces his allegiance to the tradition of motivational speaking with a sign on the wall bearing a quote attributed to William James, the American psychologist and pragmatic philosopher, brother of the novelist Henry James: “The greatest discovery of my generation is that a human being can alter his life by altering his attitudes of mind.”

A Google search generates almost 500,000 references to that passage, and with good reason. Any believer in democracy quickens to the idea that we need not be limited by our genes, social class, family, or education; we can change our destiny if we will it. Ninety years ago, a multitude of North Americans were also attracted to the theories of émile Coué, a French pharmacist inspired by the placebo effect. He invented Couéism, which involved saying, morning and evening, the mantra “Every day, in every way, I’m getting better and better.” It may sound absurd, but millions reported that it helped them.

Generations of motivators have appeared since, among them Norman Vincent Peale, the author of The Power of Positive Thinking; and Wayne Dyer, whose books include Your Erroneous Zones and Real Magic: Creating Miracles in Everyday Life. Brooker speaks well of both Peale and Dyer. He especially admires The Magic of Believing, by Claude M. Bristol, which explains “How you become what you contemplate” and “How to turn your thoughts into achievements.”

Brooker is a kind of connoisseur of motivation. He knows most of the key books, he’s heard many of the speakers, and he’s based his own presentation on what he learned from those writers, supported by his own experience. “Don’t call this a weight loss project,” he said one Sunday morning, perhaps startling a few new members who hadn’t absorbed his philosophy and believed it was merely a weight loss program. “It’s a change in thinking, a project that will lead to a new way of life.” Like the authors of the slogans on his walls, he believes we become what we think about. “Believe it can be done, visualize what you want, and you’ll turn into what you want to be.” And on another occasion: “Act as if you are already the person you want to be. This is not a dress rehearsal. Accept that this is a change for life.”

Eventually, we grasp his point: permanently losing weight will involve an alteration in our self-image. Listening to him, trying on my new suit, planning to outsmart my hunger, I realize that in two years as a student of Brooker I’ve reconsidered my rather skeptical views of the school of optimism from which he emerged. I’ve also discovered that I have more willpower than I had guessed, but only if it becomes the object of close attention. It needs to be meticulously nourished and vigorously encouraged.

If the truths exchanged through motivational training have worked for me and many others, it seems possible that the same tradition can provide a solution to mass obesity. Perhaps multitudes of fat people would grow thinner if they embraced the same fanatically careful eating Brooker teaches. They would also probably need the same kind of dedicated inspiration he provides. There are, after all, armies of marketers trying to convince us to consume more. To oppose them, we will need far more willpower than most of us now deploy.

Certainly, I needed help. The first day I entered his meeting room, I read a sign that said, “If you could do it alone, you would have done it already.” These days, when my eye falls on that sign, I occasionally think, why didn’t anyone tell me that forty years ago? But of course they were telling me, in various ways. I just wasn’t listening.