It has been demonstrated that the metabolic responses to ingested carbohydrate depend on the genetic make-up of the recipient; the type of the ingested carbohydrate molecule, and the amount and nature of protein, fat and the different trace elements in the diet. All of these elements affect the glucose tolerance, the insulin response, the number of insulin receptors and the blood lipids and the hepatic content and synthesis. The metabolic responses differ between and within species. Experiments with the selection and feeding of animals with different genetic susceptibility to the same carbohydrate intake may explain why individuals or groups with different sensitivity may develop high blood glucose and/or lipid levels, whereas other individuals will retain normal values on consuming the same amount of the carbohydrate. This also explains why, in the same community, only a certain percentage of the population will develop diabetes or carbohydrate-induced lipidemia while others will not.