In conclusion, fructose, sorbitol, and xylitol are calorie-containing non-glucose sugars that produce a lessened postprandial hyperglycemia in the absence of severe insulin insufficiency when given as pure substances. However, the day-long quantitative reduction of hyperglycemia that may result from substantial substitution of these sweeteners for glucose and sucrose in the diabetic diet, and the long-term effectiveness and safety when they are ingested in substantial quantities in mixed meals, has not been established. Certainly all overweight persons should look upon these substances as little or no help in their diet plan. It appears that use of these substances up to levels of 50--60 g/day in place of glucose or glucose-containing disaccharides has no known side effects; amounts above this level can cause diarrhea. Xylitol has been reported as possibly being tumorigenic. The use of limited amounts of fructose and sorbitol is acceptable, and may ultimately be found to provide some advantages in dietary management of persons at ideal body weight who count these calories. However, studies will be necessary before firm conclusions can be drawn regarding metabolic effects of these sweeteners and before significant use in diabetic diets can be recommended.