Considering these tiny numbers, let’s try changing our perspective and rephrasing the question. Rather than ask why some of us get excessively fat, what with all the copious food and drink we have available, perhaps the question should be why all of us don’t. It’s one thing to err on the side of undereating and go a little bit hungry all the time, but most of us don’t. We eat to satiety. So why don’t we all get fat? Certainly animals don’t walk away from their plates hungry. Why don’t they all get fat? 

Russell Wilder, the leading pre–World War II authority on obesity and diabetes at the Mayo Clinic, did ask precisely this question in 1930: “Why then do we not all grow fat?” After all, he wrote, “we continue to be protected against obesity, most of us, even though we hoodwink our appetite by various tricks, such as cocktails and wines with our meals. The whole artistry of cookery, in fact, is developed with the prime object of inducing us to eat more than we ought.” (That was almost ninety years ago when Wilder said “most of us” are protected against obesity. Today he might have to say “some of us,” but his point is still a good one.)

Gary Taubes. The Case for Keto: Rethinking Weight Control and the Science and Practice of Low-Carb/High-Fat Eating (Kindle Locations 792-796). Knopf. Kindle Edition. 

At the time Bruch wrote those words, the medical literature was already rife with reports of the remarkable success—what physicians would call the “clinical efficacy”—of diets that restricted these “innocent foodstuffs” and included copious animal products. Physicians working in hospitals and clinics around the world were publishing reports similar to Pennington’s: These unbalanced diets restricted in sugars, grains, and starches, fat-rich instead, induced significant weight loss without hunger. This was the case in report after report, independent of how many calories the patients in these various institutions were fed, whether fewer than five hundred calories a day (as at the Mayo Clinic) or whether the patients were encouraged to eat as many calories as they could, as was often the prescription. “The absence of complaints of hunger has been remarkable,” the Mayo Clinic’s Russell Wilder wrote in 1933.

Gary Taubes. The Case for Keto: Rethinking Weight Control and the Science and Practice of Low-Carb/High-Fat Eating (Kindle Locations 1157-1164). Knopf. Kindle Edition. 

Russell M. Wilder: — A Biographical Sketch (November, 1885 – December, 1959)

https://academic.oup.com/jn/article-abstract/74/1/1/4775787?redirectedFrom=PDF

Dr. Wilder's appreciation of the impor tance of nutrition in medicine was indi cated in his chairman's address to the section of Pharmacology and Therapeutics of the American Medical Association in 1930. He stated that although knowledge of nutrition was increasing rapidly in the laboratories of biochemistry and physiol ogy, the medical profession as a whole gave the subject scant attention. He pleaded "for the thoughtful attention of the members of the profession to this important field of therapeutics, for greater intellectual application on the part of practitioners to quantitative features of dietetics and for a greater amount of in struction in nutrition by medical schools." He indicated in his memoirs that "this became my theme song for the balance of my professional career.