The changing shape of childhood

Francine Kaufman gave the outgoing President’s Address, discussing our burgeoning societal recognition of obesity as a health problem for children. She traced the differing environments of the child of 40,000 years ago through that experienced today. For the neolithic child, levels of physical activity were high. Approximately one-third of energy intake came from animal protein, typically low in associated fat because animals hunted for meat (as opposed to the high fructose feeds currently used for livestock which greatly increase the saturated fat content of these foods). Half of energy intake was from high-fiber fruits and vegetables, gathered close to home, and the remainder of the diet was high in polyunsaturated fats. Dietary sodium was low. With the advent of agriculture 5,000 years ago, the availability of grain led to greater fat depots in feed animals and began to alter the dietary balance to which humans had evolved. This pattern continued during the development of the civilization of the middle ages and the Renaissance, with the wealthy often exhibiting marked obesity and gluttony being recognized as one of the “seven deadly sins.” Although the lower prevalence of diabetes among European ancestry Caucasians may reflect a diminished need for “thrifty genes,” Kaufman mentioned a current speculation that diabetes did emerge as a health problem during this period in Europe. According to this hypothesis, the European diabetes gene pool decreased as the food supply increased, while other ethnic groups, particularly with the devastation of the subsequent centuries of European colonial rule, faced periods of extreme hunger for which there was survival advantage to the retention of “thrifty genes” (1).

By 1920, food …