Pathophysiology of Obesity
Eat less and exercise more is the mantra for weight loss repeated by physicians, dietitians, and the food industry. It seems like such a simple equation: calories in - calories burned = weight management, but research does not support this outdated slogan.
Food choices have a greater influence on body metabolism than just calories. If you need 1,800 cal per day to maintain body weight and health and ate those 1,800 cal as French fries, your weight and health would not stay the same as eating 1,800 cal of lean meat and vegetables. Ingestion of high-fat, high-carbohydrate foods affect the central regulatory mechanisms for obesity management.
Sugar = Empty Calories
As Dr. John Yudkin, Professor of Nutrition and Dietetics at the University of London wrote in Pure, White and Deadly in 1986,
More research has been done on the effects on health of the bread in our diet, or the eggs, or the breakfast cereals, or the meat, or the vegetables, than about the effects of sugar ... what little research there had been already showed that sugar in the diet might be involved in the production of several conditions, including not only tooth decay and overweight but also diabetes and heart disease [1, pp. 1-2].
Dr. Yudkin points out, “There is no physiological requirement for sugar, all human nutritional needs can be met in full without having to take a single spoon of white or brown or raw sugar.” He further comments in Pure, White and Deadly, “If only a small fraction of what is already known about the effects of sugar were to be revealed in relation to any other material used as a food additive, that material would promptly be banned” [1, p. 2].