1. Blunted insulin secretion,
2. A resistance to the action of the same, or
3. A mixture of both.

The vast majority of patients are diagnosed with one of the following categories: diabetes mellitus type 1, produced by an absolute deficiency in insulin secretion, diabetes mellitus type 2, caused by a combination of resistance to insulin action, and inadequate compensatory response of the pancreas.

Diagnostic Criteria
The criteria for diagnosis of diabetes mellitus have recently been reviewed by a panel appointed by the American Diabetes Association (ADA) and the World Health Organization (WHO). There are three different criteria to diagnose diabetes:

1.The presence of classic symptoms (polydipsia, polyphagia, polyuria and weight loss), with the incidental finding without considering the time elapsed since the last meal, a blood glucose (blood sugar) levels above 200 mg / dl ( 11.1 mmol / l).
2. A fasting glucose 126 mg / dl (7 mmol / l).
3. The presence of glucose levels above 200 mg / dl (11.1 mmol / l) in an analysis of two hours after an oral glucose load of 75 grams (test performed according to WHO criteria).

The isolated finding of either of these criteria is not sufficient to establish the diagnosis. Should be confirmed in the following days the same, or any of the other two.

The balance on a diet of nutrient components toods is necessary for any person:

• The energy-producing carbohydrates (one gram provides 4 calories). It is mainly found in foods such as cereals, pulses, potatoes and various fruits.

• Fats produce much energy, we are mainly oil, margarine, butter, bacon, butter, etc …

• The proteins serve mainly to form tissues, muscles, etc … The animal received mainly from meat, fish, eggs, milk and fish. The plant origin are found mainly in legumes.

• Vitamins and minerals have no caloric value and are received mainly through vegetables, fruits and vegetables.

The eating plan: the number of them will depend on many factors such as age, sex, physical activity and whether or not overweight. Usually that is a diet of 1,500 Kcal. The breakdown of the immediate principles must be done as follows:
50 – 60% as carbohydrate.
25 to 30% as fat.
15% as fat.

• It should avoid simple carbohydrates or simple sugars. The proteins must be at least 50% of animal origin. The fat must come in their half of vegetables.

• The number of meals recommended is 6. Three main meals (breakfast, lunch and dinner) and three intermediate midmorning snack and before bed) to avoid the abrupt changes in sugar.

• Foods rich in fiber are recommended because they help reduce the oscillations of sugar, this is recommended so-called grain products.

• Special diabetic foods are not generally recommended.

• It should avoid eating foods with sugar such as cakes, pastries, cookies and sweetened with saccharin.

• You should not drink alcoholic beverages because they provide calories and can unbalance the diet.

• Soft drinks are not recommended because of its high sugar content.

• You can use equivalence tables to change food for others.

Standard menu of diabetes:

Breakfast:

1 glass of skimmed milk, alone or with coffee, tea (no sugar, saccharin or aspartame –
chaff)
1 / 2 piece of bread with olive oil, cheese or tomato.

Midmorning:

1 piece of fruit.

Lunch:

A dish of meat or fish or vegetable stew / grains / pasta
Acompañamineto salad or vegetables or potatoes (baked or cooked).
1 / 4 piece of bread.
Yoghurt or low-fat cheese or fruit.

Snack:

1 piece of fruit.
Nonfat yogurt or 1 cup of skim milk.

Dinner:

A dish of meat or fish or vegetable stew / grains / pasta
Acompañamineto salad or vegetables or potatoes (baked or cooked).
1 / 4 piece of bread.
Yoghurt or low-fat cheese or fruit.

Before bed:

1 piece of fruit or 1 yoghurt or 1 cup of skim milk.