Chronic kidney disease (CKD) is an issue faced by many Americans, as it is often a complication of many chronic diseases, such as hypertension and diabetes. The American Association of Kidney Patients notes that this disease has a slow onset, usually occurring over months to years, where eventual loss of kidney function will ensue. The loss is often permanent and can conclude in the need for dialysis or kidney transplant. Although diet may not be able to reverse these changes, it can slow their occurrence and prevent worsening of the disease.
Considerations
Chronic kidney disease patients must keep an eye on dietary factors that place stress on their kidneys. These factors include daily calorie consumption and protein intake, according to guidelines based on your body composition. Other considerations include dietary levels of certain electrolytes, including sodium, potassium and phosphorus. Even excess water, when consumed by people with compromised kidney function, can have deleterious effects, so hydration must be monitored carefully.
Protein
Protein is a macronutrient that must be monitored closely in chronic kidney disease patients. Foods such as meat, poultry, fish and eggs are considered dense sources of protein. The University of Pittsburgh Medical Center, or UPMC, notes that the kidneys excrete the end product of protein metabolism, urea. In a CKD patient, the amounts of urea produced and thus the amounts of protein ingested must be carefully monitored to limit stress on an already weakened organ system. The Recommended Dietary Allowances (RDA) suggests that the average person consume 0.8 grams of protein per kilogram of body weight. The American Association of Kidney Patients, or AAKP, on the other hand, recommends that chronic kidney disease patients limit protein to 0.6 to a maximum of 0.75 grams per kilogram of ideal body weight.
Calories
Chronic kidney disease can lead to weight and muscle mass loss if a sufficient number of calories are not taken in, notes the UPMC. Calorie intake, according to AAKP nutritionist, Peggy Harum, should equal 35 calories per kilogram of body weight for people under 60 years of age. Adults over 60 need slightly less; she recommends 30 calories per kilogram of weight. A 2007 National Kidney Foundation survey of CKD patients found that, on average, many patients were actually consuming fewer calories than recommended.
Electrolytes
Electrolytes are the charged ions circulating in the plasma portion of the blood and involved in many reactions in the body. The kidneys should be a filter for these electrolytes, allowing reabsorption or secretion of them as needed, to keep body levels properly balanced. Levels of electrolytes such as sodium, potassium and phosphorus are routinely surveyed as indicators of kidney function.
The AAKP notes that when the kidneys are underfunctioning, levels of these electrolytes can build up in the bloodstream and become toxic. Additionally, sodium retention can raise blood pressure, which also worsens kidney function over time. Peggy Harum suggests that food sources rich in potassium, such as bananas, oranges, prunes and tomatoes; phosphorus, which includes milk, beans, peas, nuts and chocolate; and sodium, such as salt, bacon, ham and processed meats and fast foods, should all be avoided.
Fluids
In addition to removing toxic wastes from the body, the primary role of the kidneys is to remove water. Harum notes that kidney failure is aptly named because toward the end stages of the disease, the kidneys fail to make urine. The AAKP notes that only in the final stages of the disease, stages 4 and 5, is it recommended that fluid intake be reduced.
