A diabetic must restrict all foods -- not only carbohydrates, because even fat and protein foods transform into sugar in the body. For the sake of good health an long life, it is advisable for every person to be slightly underweight, but for the diabetic it is obligatory to be underweight as a preventive of serious complication.

The restricted diet and insulin injections are the life saving agents in Type I diabetes. The diet is flexible and adjustable--- it should yield between 1500 and 2000 calories under normal conditions. The diet restriction is all the important treatment in diabetes.

The World Health Organisation (WHO) has issued diagnostic criteria for Diabetes Mellitus (DM) on the premise that DM is defined as the level of glycemia at which diabetes - specific complications occur rather than mark deviations from a population based mean.

The revised criterion emphasizes the fasting plasma glucose (FPG) as a reliable and convenient test for diagnosing DM in asymptomatic individuals. A random plasma glucose concentration > 200mg/dl ( 100 c.c.) accompanied by classic symptoms is sufficient for the diagnosis of DM.

Glucose tolerance is classified into 3 categories based on FPG:

FPG < 100 mg/dl --- normal.
FPG > 100 mg/dl but < 126 mg/dl impaired fasting glucose (IFG).
FPG > 126 mg/dl - it warrants diagnosis of DM.

Diabetes mellitus (DM) is now classified on the basis of its etiology, i.e, the pathogenic process that leads to hyperglycemia, as opposed to earlier criteria such as age of most or type of therapy. 2 broad categories are recognised.

Type 1 diabetics : usually developing absolute insulin deficiency by destruction of beta cells of pancreas, either autoimmune or idiopathic ( without known cause).

Type 2 diabetes: ranging from predominantly insulin deficiency with relative insulin deficiency, predominantly insulin secretary defect with insulin resistance.

Although Type 1 diabetes most commonly develops before the age of 30, an autoimmune beta cell destructive process can develop at any age. Again, many individuals with Type 2 diabetics eventually require insulin treatment for control of glycemia.

For this, the long used terms insulin-dependent diabetes mellitus (IDDM) and non-insulin- dependent diabetes mellitus (NIDDM) are becoming absolute.