Maimonides & Metabolism

A reconsideration of the physiology of weight loss, supported by the writings of the Jewish philosopher Maimonides.

In recent years, discussions about losing weight have been dominated by the protein-carbohydrate duo. Although debut author Herschlag hews closely to the conventional wisdom by recommending a diet low in carbs, he expands the terms of the debate significantly. First, he provides an account of how simple caloric restriction can counterproductively increase one’s weight. Sustainable weight loss, he says, requires creating a healthy balance among four different hormones: insulin, cortisol, leptin, and ghrelin. Although the effects of insulin on weight management have been widely covered before, the other three hormonal secretions have been comparatively neglected in other books. Here, for example, the author writes that eating too few calories can increase the release of ghrelin, which thereby increases not only hunger but also the production of fat cells. Likewise, he notes, the simultaneous release of insulin and cortisol, which responds to low blood sugar levels by stimulating a release of blood sugar from the liver, also generates new fat cells. The goal of any good diet, according to Herschlag, should be maximizing the process of apoptosis, or the burning of fat cells, while minimizing the production of new fat cells. This leads to some unconventional counsel; for example, since cortisol levels are at their peak directly after we wake, the author recommends postponing breakfast for three hours. Here and there, Herschlag observes points of agreement between his scientific findings and the ancient writings of the Jewish sage Maimonides, but these asides will likely be little more than a matter of curiosity for readers who are merely interested in losing weight. Although much of the practical advice ends up treading familiar ground, this is a considerably deeper and more rigorous treatment of the subject than normally offered. Its appraisal of some of the more popular diet fads is also helpful. However, readers should take note of the author’s disclaimer that despite his training at the prestigious Wingate Institute, he’s not an “expert or authority” and doesn’t feel obligated to present all the sides in each debate he addresses.

Readers looking to understand all the factors in weight-loss management will find this a good supplement to material produced by experts.