The kidneys remove unwanted salts, waste products, and other chemicals from the plasma along with the water in which they are dissolved. Nutrition is very important in maintaining a healthy life when diagnosed with kidney disease. Nutritional management is individualized. Nutrition may affect persons who have, or are at risk for developing renal disease. The intake of certain nutrients may influence the rate of progression of renal failure in persons with underlying renal disease. High-protein diets can strain the kidneys to the point of failure.
When food is broken down in the stomach and intestines, wastes are formed. These wastes are removed by the kidneys. However, if kidneys are not functioning properly, these waste products will build up in the bloodstream and you may feel weak, tired, nauseated and become ill. The other balancing act the kidneys perform is the regulation of the body's fluid balance. Some patients with kidney disease may retain fluid, leading to puffiness, swollen ankles, hands and feet and breathlessness
Treatment of renal disease may demand severe dietary restrictions or induce nutrient losses. Dietary management of this condition, therefore, must provide protein, energy, and other essential nutrients in amounts adequate to avoid deficiencies but sufficiently restricted to avoid stressing the diminished excretory capacity of the diseased kidney.
The goals of nutritional therapy for both acute and chronic renal failure are to maintain optimal nutritional status, to minimize the toxic effects of excess urea in the blood, to prevent loss of lean body mass, to promote patient well-being, to retard the progression of renal failure, and to postpone initiation of dialysis.
Maintaining a healthy weight is important for everyone. If protein has been restricted in your diet, your energy requirements may need to be met by increasing the amount of fats (polyunsaturated and monounsaturated) and carbohydrates in your diet. Otherwise, you will lose weight and continue to do so, which is undesirable. Once dialysis is commenced, your protein requirements increase, as some proteins are lost from the body during each dialysis session. As your feeling of well- being and appetite improves, you will find it easier to incorporate a greater variety of foods to meet your requirements.
Too little protein may cause:
• loss of muscle bulk and wasting
• lack of energy
Too much protein forms excess urea which may cause :
• nausea and vomiting
• a bad taste in the mouth
• bad breath
• poor memory and concentration
Foods high in protein include :
• cheese, milk and other dairy foods (yoghurt, cheese)
• nuts, seeds and legumes
Salt affects the amount of fluid the body retains. Salt also increases thirst, which can lead to drinking more fluid than your kidneys can excrete, leading to fluid retention.
This excess fluid may cause:
• high blood pressure
• swelling of ankles, feet, hands and puffiness under the eyes
• shortness of breath
In most cases, the amount of salt in your diet will need to be reduced. Your doctor and dietitian can advise about this.
Foods high in salt include:
• processed foods such as ham, sausage and meats
• dry, canned and pickles made with fish and prawns
• fast food eg. pizza, pies, hamburgers, sausage rolls
• salty snacks eg.papads , chips, salted nuts
• sauces and pickles
• salted seasonings e.g. stock cubes, celery and vegetable salts
Beware of salt substitutes as some contain potassium instead of sodium.
Potassium is an essential mineral in the body which helps nerve endings and muscles work well. If the level of potassium is too high or low in the blood, it can cause irregularity of your heart beat. In fact, potassium levels outside the normal range may cause the heart to stop. How much potassium you can you have? This depends on your blood results, as well as the amount of urine you are passing.
Foods high in potassium include:
• dhal, whole grams and its washed and cook
• tinned and homemade soup
• red wine, cider, stout
• bananas, avocados, apricots, rock melons, spinach, mushrooms
• dried peas, beans, baked beans
• potatoes, potato crisps, pumpkin
• chocolates, cocoa,
• tomato pastes and purees
• fruit and vegetable juices
• dried fruit and fruit cake
• stone fruits
• nuts and seeds
A tip for reducing potassium intake is to cut the vegetables into small pieces, boil them and drain off the water. Not all fruits and vegetables have the same amounts of potassium. Ask your dietitian to outline what is appropriate for you.
The amount of phosphate allowed depends on your blood tests.
Foods high in phosphate include:
• nuts, seeds and peanut butter
• dried peas and beans and baked beans
• processed bran cereals
• sardines and fish pastes
• cheese, milk and other dairy products
When kidney function deteriorates, the body can retain fluid. Some people may need to limit their fluid intake to minimize this. Your recommended fluid intake will be dependent on your urine output, fluid build-up and your blood pressure. The usual allowance is equal to the urine output plus 500mls.
• water and ice
• tea, coffee, juices, milk and milk products
• gravy, sauces and soups
• ice cream, jelly, custard and yoghurt
Some tips for restricting fluids:
• suck ice cubes to quench thirst
• sip small amounts throughout the day
• use smaller cups and glasses
Remember that foods containing fluids need to be included in your fluid allowance.
Other points to remember
• Nutritional care plan needs to be individualized based on degree of renal function.
• It may be difficult to meet vitamin requirements orally and doctor may prescribe a supplement.
• Ask questions till you understand about your diet.
• Initially you may need to measure foods and fluids; for greater accuracy, measure with a cup or scale and don't guess.
• Take your medication as prescribed.
• Organize for regular reviews / follow-up with your dietitian.
• Follow your trends in body weight, blood pressure and blood values.
• Inform your doctor or dietitian if you are losing weight or have any concerns about your diet.
• Following the suggested nutritional care plan may not treat or cure your kidney problem but it could help you reduce some of the symptoms and hence improve your general feeling of well being.