In mild cases of diabetes the results obtainable by diet are entirely satisfactory and the milder the case the less the food restriction necessary. In severe cases of diabetes the dietary treatment alone is less satisfactory because the diet has to be cut so low that the patient is improperly nourished. Before the discovery of insulin was made, every such case presented a bitter dilemma. Either the diet was restricted to the point where the patient literally starved to death, or the patient could be fed; but, in that case, death from diabetic coma was to be anticipated. It is in such cases, particularly, that insulin is proving a boon. With insulin at our disposal, cases of severe diabetes can be converted into mild cases. All that is necessary is to give enough extra insulin every day to raise the patient’s tolerance for sugar, and then, with a careful but adequate diet, he can enjoy normal strength and health and carry on with his usual occupation. This is not curing diabetes, but it is eliminating the worst of its terrors. _The diet can not be disregarded._--Some persons may ask why dieting is necessary with insulin? If, as seems true, the only metabolic disturbance in diabetes is a lack of sufficient insulin, then we should be able to correct this fault completely by giving sufficient insulin, and to eat what we want. This may be sound, theoretically, but is impractical for the following reason. An uncontrolled normal diet contains approximately 300 grams, or 10 ounces of carbohydrate, 150 grams, or 5 ounces of protein, and 90 grams, or 3 ounces of fat. In the course of assimilation, about 400 grams of sugar are derived therefrom, and, to metabolize such an amount of sugar, 150 to 300 units of insulin must be necessary. A normal person probably makes, in his pancreas, 200 or 300 units of insulin a day, which is sufficient for any normal demand, but this natural insulin is doled out to his tissues, a bit at a time, so that there is never an excess of insulin in the blood. _Excessive insulin harmful._--In severe diabetes the pancreas manufactures very little insulin, not more than 20 or 30 units, and the balance necessary for the day’s work must be given by hypodermic syringe in two or three doses. If the total amount of extra insulin necessary daily were 150 units, each hypodermic injection would be 50 units, and it is difficult to give such large doses as this without causing a temporary excess of insulin in the blood. Unfortunately, excessive insulin is as disagreeable as inadequate insulin. When too much insulin is present in the blood, the blood sugar falls to very low levels and a reaction occurs with symptoms that may be alarming, and results that may be serious. Consequently, very large single doses of insulin must be avoided and the total amount of sugar entering the body daily must be measured and made to balance with the insulin doses. This means dieting.