The hypothesis I plan to investigate is this: that somewhere within the human body system may exist a key, or a set of keys, to natural weight homeostasis. In other words, I want to find out whether my body can regulate itself at a “normal weight”, without life having to become one long stressful diet just to tread water. This is urgent for me because my past shows that I lack the willpower to cut calories ad infinitum. I need more than willpower to stay at this weight: I need a mechanism that, once set in gear, could supervise itself.

Maintenance allows me the freedom to undertake some experiments in eating. On the reducing diet, I was afraid to experiment much in case I stalled or put on weight; but I kept detailed food journals that eventually began to suggest a number of lines of enquiry. I did make one powerful discovery during my diet, which triggered the hypothesis that the body may have the ability to control calorie balance, even the body of a “Mr Fatten Easily”, as Richard Mackarness called people like myself.

The only two books I read before starting my low-calorie diet were Dr Richard Mackarness’s Eat Fat, and Grow Slim (1970s edition) and Dr John Briffa’s Waist Disposal, a diet book for men. Always alert for loopholes in conventional wisdom, I was struck by Dr Briffa’s insistence that nuts are not fattening. I therefore tried eating handfuls of walnuts for snacks, instead of my former biscuits, crisps, and so forth. Over time, I noticed I did not gain more or lose less weight on the days I ate nuts than on the days I did not (I wasn’t counting calories at that time, because the two doctors said it wasn’t necessary to do so). As a result, I increased the amount of nuts I ate each day, and, to my surprise, my weight loss continued unimpeded. After a while, I began eating quite large amounts of nuts each day in addition to my diet food, and still they made no difference. In fact, I came to suspect them of actually helping me to lose weight, so I increased them even more. Some days, where in the past I would have fasted, I ate nothing but great dishes of nuts. On four occasions, I ate nothing but nuts for a week or more to see what would happen; I lost weight at a faster rate during those weeks than at any other time on the diet. Once I reached my target weight, I calculated that 21.7% of the weight I'd lost had been on days I had eaten only nuts. I will list the results of these nut experiments in another post; but for now I'd add that results differed between different types of nut. The best nuts for weight loss, I found, were mixed, unsalted nuts, walnuts, pecans, and Brazil nuts; peanuts and pine nuts were mildly beneficial; cashews were neutral, and almonds, if anything, were slightly fattening. Roasted or salted nuts were very fattening. I did not eat hazelnuts on their own, but as they were in the mixed nuts, I expect they work as well as any. I didn't eat macadamias because I don’t like them.

So fascinated was I by this seemingly miraculous effect of nuts that I began looking up the research about them, starting with the references in Briffa's book. Not only did I find evidence for a similar effect in countless controlled scientific trials, but the published analyses of the results prompted me then to investigate whether other foods might act on the digestive system in similar ways to the nuts. I have not been disappointed.