So far as I know, the oldest in the English language at least, is Banting's Letter on Corpulence. Having lost weight and dramatically improved his health on a low carbohydrate diet. Banting wrote and self-published the book back in the Mid-Victorian era, and he distributed it for free.
Read More »Obesity Undone: Fat Then Fit Now; A Life Beyond Weight Loss, Edition 2 by Dr. Joe Leonardi
On March 1, 2008, Doc Joe weighed a ponderous, pachydermian and unhealthy 340 pounds. One year later he weighed in at 210 pounds. He not only lost weight --- he regained his health, fitness and wellness.
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