ABSTRACT
This chapter describes the acute responses and the adaptive effects observed after the intake of fructose by experimental animals and humans on the levels of blood glucose and insulin and on insulin sensitivity. Although diagnosis of clinical glucose intolerance and diabetes is based on elevations of fasting and postprandial blood glucose levels, blood insulin levels may be a more sensitive indicator of impairment of glucose tolerance. Animals with the greatest increase in blood glucose were mated, as were those with the smallest increase. The mechanisms by which dietary fructose may produce the reported deterioration of glucose tolerance in experimental animals are based on the observed effects of fructose on carbohydrate, lipid, and nucleotide metabolism. Metabolic effects of fructose as they pertain to glucose tolerance can be divided into three general categories: direct effects on insulin secretion, effects through actions on carbohydrate metabolism, and effects through actions on lipid metabolism.
