A low-protein diet is used in people with abnormal kidney function to prevent worsening of their kidney disease. The diet is often low in sodium and potassium as well. For some people on this diet, fluid restriction is also necessary. And if you have diabetes along with kidney disease, a low-carbohydrate diet may be necessary.

This special diet is very helpful because it decreases the stress on the kidney.

• Protein is restricted to decrease the protein load on the kidney and slow down the progression of kidney disease.
• Sodium may be restricted to improve blood pressure control and to avoid fluid accumulation.
• Potassium is restricted if it is not excreted effectively and levels in the blood are high. When you have too much potassium in your blood, dangerous heart rhythms may result.

The controlled amounts of each of these nutrients are based on the blood levels of potassium, sodium, protein (measured as total protein and albumin), and urea (a waste product normally excreted in the urine).

Fluid is only restricted if you accumulate excessive amounts in your body.

Calcium and phosphorus, two other important minerals in the body, are also followed closely. Phosphorous can become too high if you have kidney disease. Calcium can become too low. If the blood levels of these two minerals indicate that you need to adjust your intake of them, then the amounts allowed in your diet are altered. If that alone is not enough, supplements and medications are used.

If you have kidney disease, you should get most of your calories from complex carbohydrates. In other words, you should tend to consume carbohydrates instead of proteins. Calories from fats should be from monounsaturated and polyunsaturated fats.

If you are diabetic, your dietitian and doctor will help you focus on low-to-moderate carbohydrates along with healthy fats.

Your kidney specialist should refer you to a registered dietitian for nutrition information specific to kidney disease -- some even specialize in kidney diets. The Kidney Foundation has chapters in most states and is an excellent resource for programs and educational materials for people with kidney disease and their families.

A low-protein diet can be deficient in:

• Some of the essential amino acids
• The vitamins niacin, thiamine, and riboflavin
• The minerals calcium and iron

In advanced kidney disease, a low-protein diet can lead to malnutrition and should only be implemented under the guidance of a kidney specialist.