Impaired Glucose Tolerance is a state in which the organism becomes incapable of controlling blood glucose concentrations, Diabetes Mellitus itself has not fully developed, yet. Impaired Glucose Tolerance is found in patients with glycemia values of oral glucose tolerance test after two hours between 7.8 and 11.0 mmol/l. These patients should be informed that although they do not suffer from diabetes yet, they may be susceptible to it. Unless they change their life styles, especially regarding their energy intake and physical activity, the disease is most probably going to present itself in the relatively near future.