This week we look at one of the most ubiquitous things in modern dieting... calorie counting. When did we first start paying attention to the caloric content of food and worrying about how much energy we were taking in vs. burning off? The popularization of counting calories for weight loss and management was popularized by Lulu Hunt Peters, a doctor who had been the head of the pathology lab at Los Angeles County General Hospital and who was the first person to look at the calorie as something to pay attention to when trying to lose weight as opposed to simply a way to look at nutritive value of food. Peters successfully used watching calorie intake to lose a substantial amount of weight and then became a very popular figure in the burgeoning weight loss industry writing "Diet and Health: With Key to the Calories" in 1918 which became a best seller.