The approach the book takes is that weight is a problem to be solved, just like any other problem, and it examines the problem from an engineering and management perspective. The thesis is that people who have chronic weight problems (e.g. the author, e.g. this author) have a broken appetite. Some people have bad eyesight, some have faulty appetite signals. No big deal. Except that you can't just go to the CVS and buy corrective appetite-glasses.
So the thing to do is to build a set of external tools that can do what the appetite should be doing. In building the set of tools, he brings up a few key points:
1. Your weight varies day-to-day by much more than the amount of fat you gained or lost, because of water. But, it is mathematically simple to calculate a trend line from your weight data that will give you real, solid data that you can rely on week after week. In other words, we can accurately measure the results of our actions.
2. People (or at least, people who need to lose weight) are assumed to be terrible at estimating calories. Look it up, plan it out, know what you eat. You can also control the input.
3. If you have bad eyesight, you will need glasses for the rest of your life (or until you get laser surgery.) If you have a faulty appetite, you have to apply external tools for the rest of your life**. If you do, you can keep the weight off.
And the rest is details, such as knowing that the first 48-72 hours of a diet are the most painful, such as forming a habit to weigh in, such as knowing how to counts calories, and all that other common sense (!) stuff.
I've been on a diet for about three weeks now, but over the past two days I read the book and I'm ready now to get really serious. I've been unhappy with my weight basically, forever. But I've always tried to manage it intuitively, and I've always denied, at some level that my appetite was broken. Admitting that it's broken is actually really liberating. Seeing a path to correct it is really empowering***.
I don't know if this book would work as well for non-engineers as it seems to have worked for me, but hey it's free and it's online.
*Nothing was actually promised.
**But you DO NOT have to be hungry for the rest of your life. Getting past the worst first few days has made a new man of me.
***Yes, I will have to weigh myself every morning, for the rest of my life. That now seems a small price to pay, which is interesting because I've balked at the same idea many times before. But knowing that the only thing I care about is the trend line, not the number itself, is really comforting to me. Removing the noise from the signal and shortening the feedback loop is an extremely good optimization for any control system. Weight is a control system. My natural weight control system is broken, but I can fix it with tools.