Looks like all those martini lunches at Sterling Cooper were just a well-meaning path to weight loss. Before there was the Atkins Diet, there was The Drinking Man's Diet. One of the original high-protein, low-carb regimens, the 1964 fad diet proposed that eating "man-type" food (think steak, lobster, and squab) would lead to weight loss. And to top it off, wash it down with a martini, or Don Draper's favorite, an old-fashioned! As long as carbs were kept under 60 grams per day, authors claimed that the weight would melt off. They failed to mention, however, how unhealthy a diet of fat and alcohol can be. The diet took off and 2.4 million copies were sold in just two years.
From the book:
"Did you ever hear of a diet which was fun to follow? A diet which would let you have two martinis before lunch, and a thick steak generously spread with Sauce Béarnaise, so that you could make your sale in a relaxed atmosphere and go back to the office without worrying about having gained so much as an ounce?"