Good nutrition
Good nutrition is very important and it should be looked on as an integral part of your treatment along with your dialysis and your medication.
HD for the majority of patients takes place 2-3 times a week for 3-5 hours at a time. Any special diet that HD patients are recommended to follow takes this into account as toxins can build up quickly between sessions.
Protein
Protein is needed for the repair and maintenance of body tissue and is a vital component of body fluids including blood.
The breakdown products of proteins are:
- Urea - chiefly from protein provided by foods and
- Creatinine - produced from normal muscle 'turnover'.
These substances are both removed quite efficiently by HD and this allows for a good intake of protein per day.
This is important as low levels of protein in the blood (hypo-proeinaemia) must be avoided as it can lead to:
- A type of fluid retention which is difficult to remove by dialysis and
- A reduction in the body's ability to fight infection.
- A good proportion of the protein eaten should be of the type that is similar in 'make up' to our own body proteins such as meat, fish, and eggs
- To calculate the amount of protein that is recommended for each person on HD a formula is used by the Dietitian based on that particular person's Ideal Body Weight - please note that Ideal Body Weight is used for this one purpose only. It must not be confused with 'dry weight'.
- On each individual's Diet Sheet there is a suggested menu plan which when filled in by the Renal Dietitian with weights of meat and fish will reflect the correct amount of protein that is recommended for that particular person.
- During periods of illness it can sometimes be difficult to eat enough protein. Nutritional supplements ( as drinks, powders and puddings) are available but not all are suitable for HD patients - the Renal Dietitian will give advice on the hest ones for you to take. Some of these supplements are available on prescription from the GP.
Energy (Calories)
The energy needs of people on HD are no different to the rest of the population. Most of the energy in our food comes from:
Carbohydrates - sugars, breads, cereals, pasta, rice, noodles, chapatis, biscuits, crackers,
Fats - margarine, butter, vegetable oils
An excessive intake of fats (especially animal fats) can raise blood cholesterol levels and increase the risk of developing heart disease.
It is not difficult to cut down on the amount of fat eaten and HD patients are encouraged to do this by:
- Taking skimmed or semi-skimmed milk in place of full cream milk,
- Trimming fat from meat,
- Putting away the chip pan and frying pan,
- Avoiding too much pastry, cream, mayonnaise, full fat cream cheese, biscuits, cakes;
- Using a polyunsaturated or monounsaturated margarine spread thinly.
Potassium
Potassium is a mineral that is found within the cells of body tissue. It helps in the regulation of the functions of the heart. When blood levels fluctuate this can cause the heart to develop abnormal rhythms and in extreme cases to stop.
When the body's ability to excrete excess Potassium through the kidneys is diminished or absent the amount in the blood will rise to dangerous levels. Haemodialysis does lower the potassium level in the blood but it builds up very quickly between sessions.
There are a number of foods that need to be avoided or reduced due to their very high potassium content ( these are all written on the Haemodialysis diet sheet and include such items as bananas, chocolate, crisps, baked beans, coffee)
Phosphate
Phosphate is another mineral that the healthy kidneys remove from the blood when there is an excess.Within the body phosphate works very closely with Calcium and it is vital to have just the right balance between these two in order to keep bones strong and healthy.
When excess phosphate is not removed from the blood the level will rise and the body reacts by obtaining extra calcium from the bones to restore this balance. The result can be irreversible bone disease.
Phosphates are large molecules which dialysis does not get rid of particularly easily.
There are two other additional strategies which can be used to help control blood phosphate levels:
- Reducing the intake of phosphate rich foods - a list is provided on your Diet Sheet.
- They include such foods as hard cheeses, liver, sardines, etc.
- Always take WITHOUT FAIL any phosphate binders that have been prescribed with your meals as they help to reduce the amount of Phosphate absorbed by the body from food.
Salt and Fluid
Restricting the intake of sodium (mostly from salt) and fluid becomes important if the production of urine decreases. Excess fluid accumulation must be prevented as its removal can result in uncomfortable and lengthy dialysis sessions.
Fluid retention can also cause high blood pressure and may eventually contribute to heart disease. Even salt in cooking may need to be avoided if urine production does stop altogether - herbs and spices can be very useful in order to add extra flavour.
Salty foods such as bacon, sausages, and tinned meats can sometimes cause excessive thirst and are best limited if not avoided altogether.