Somewhere in this book, Dr Ignatius Brady, a weight-loss physician and science writer proclaims: ‘The unfortunate truth is neither our current, nor our future weight is under our control.’ For the present reviewer whose weight gradually came down from 87 kilograms to 74 kilograms within a year and then remained steady for the last three years, that too by simply avoiding all wheat products and sugar in his food items, that statement came as a shock. It was more of a shock because unless he had given up wheat, he wouldn’t have known what magic abstinence from that one food item, making no other changes in diet or activity, can have on body weight.
According to Dr Brady neither low-carb nor low-fat diets ‘solve the obesity problem because they produce tiny amounts of weight loss and fail when participants go back to “eating as usual”‘. Unfortunately, the present reviewer’s personal experience is very different with low-carb diets although there has been no substantial decrease in his fat intake. From his personal experience, this reviewer fails to understand why low-carbohydrate diet has to be ‘insatiating’ and why the ‘participants’ would go back to ‘eating as usual’. It is incomprehensible for him why the low-carbohydrate diet (it’s not a no-carbohydrate diet) can’t be a ‘sustainable way of eating to maintain health’!
The main thesis of Dr Brady’s book appears to be what is called the ‘protein leverage’ hypothesis, that changes in the availability of protein can trigger large changes in the behaviour of animals. The author says that people who eat less protein are more likely to have weight problems. He also claims that historically most researchers have discounted proteins ‘because it is such a small portion of our total intake and because it is so constant across time and geography’. Is protein intake really so constant across time and geography? Do humans eat the same amount of protein everywhere? Does a vegetarian south Indian Brahmin, for example, eat the same amount of protein as a meat-eating European? That just doesn’t sound very plausible at all.
Thus the main argument of the book centres round the idea that the modern obesity and diabetes epidemics are the result of the body’s tendency to over-consume in order to compensate for the deficiency of protein in the human diet. No one would argue that protein is an essential part of the diet. But to consider that sufficient protein in our diets can decrease obesity sounds too simplistic especially because of the apparent connection between affluence and obesity. It is hard to believe that the diet of the affluent classes anywhere is more deficient in protein compared to those who can’t afford to buy the relatively more expensive plant and animal proteins.
It is to Dr Brady’s credit, however, that he falls short of giving that one big answer to the obesity problem in this book. He appears to be sincerely circumspect in drawing conclusions and draws the readers’ attention to all the gray areas that remain in this field. Yet it is difficult to go with the theory that dietary carbohydrates do not cause us to gain weight. This book may be an interesting read if you have a theoretical interest in diet and its effect on body weight. But if you look for some specific dietary rules to follow, What is Fat For? may not help you at all.
The reviewer is obligated to let the readers know that he received a free copy of the book from Netgalley in exchange for an honest review.