Overview

This information is for people with kidney disease who are having peritoneal dialysis treatment.

Peritoneal dialysis is a type of kidney replacement therapy. It is used when your kidneys have stopped, or almost stopped, working. The treatment involves using the inner lining of the stomach (peritoneal membrane) to remove:

• harmful waste products
• too much fluid in the body

People on peritoneal dialysis can generally follow a less restricted diet than those who are on haemodialysis, or have decided not to have dialysis.

During peritoneal dialysis, your body:

• takes in (absorbs) sugar (dextrose) from the dialysis fluid
• loses some protein with each exchange

Eating well while on peritoneal dialysis can help you to stay and feel healthy. It is generally recommended that you follow a healthy, balanced and varied diet to get all of the nutrients you need.

This information covers:

• how a kidney dietitian can help if you are on peritoneal dialysis
• how to get enough energy from your food
• how to get enough protein in your diet
• how to manage your fluid levels
• how to reduce the salt in your diet
• how to control the potassium in your diet
• how to control the phosphate in your diet
• how to reduce the risk of constipation
• how to eat well if you have a poor appetite
• how to keep to a healthy weight

If you have any more questions not covered here, please contact us. 

How a kidney dietitian can help you

This information gives general guidance if you are on peritoneal dialysis. A kidney (renal) dietitian can:

• explain how to apply the guidance practically to your own diet
• check that you are not unnecessarily restricting foods that could be good for you

Maintaining your energy levels

It is important to make sure that you get enough energy from the food you eat. This helps to make sure that you:

• do not lose weight unintentionally
• have enough energy to do the activities that you enjoy

You get energy from all foods. However, some good sources of energy include starchy foods like:

• bread
• rice
• pasta
• noodles
• potatoes
• plantain (a tropical fruit similar to a banana with green skin)
• yams (sweet potatoes)
• fufu (dough made from boiled and ground plantain or cassava)
• chapattis

Try to include 1 serving of these foods at each of your meals.

The peritoneal dialysis fluid contains sugar (dextrose), which gives your body extra calories. If you gain weight while on peritoneal dialysis, you may need to restrict some non-nutritious foods in your diet. Examples are fizzy drinks, crisps and chocolate that contain a lot of sugar.

If you do regular physical activity, this will help you reach and keep to a healthy weight.

Getting enough protein in your diet

Your body needs protein for growth and repair.

When you start peritoneal dialysis, it is important to make sure that your body gets enough protein to prevent malnutrition. If you do not eat enough protein, you will have a higher risk of losing muscle strength and getting weaker.

You lose a small amount of protein during peritoneal dialysis. This means that you need to eat more protein. 

The amount of protein that you need depends on your body size and is different for each individual. As a guide, try to have 3 good helpings of protein-rich foods every day as part of your meals.

Protein-rich foods include:

• meat and poultry, such as beef, lamb, pork, chicken and turkey
• fish
• eggs (limit these to 4 a week)
• dairy foods
• tofu and soya products
• beans and pulses

It can be more challenging to get enough protein if you are vegetarian or vegan.

You need even more protein during episodes of peritonitis (an infection of the inner lining of the stomach). This is because your body then loses a higher amount of protein.

If you have peritonitis, you may need to include extra-high protein snacks in your diet. Examples are:

• yoghurt
• custard
• cheese
• hummus

If you have a reduced appetite, you might need to take oral nutritional supplements while being treated for peritonitis.

Your renal dietitian can give you more information on ways to increase the protein in your diet.

Managing your fluid levels

If you are having peritoneal dialysis treatment, you may need to limit the amount that you drink (your fluid intake). This is to avoid fluid building up in your body.

When too much fluid builds up in your body, this is called fluid overload. It can cause shortness of breath and swelling in parts of your body. In the long term, fluid overload can damage your heart.

The amount that you can drink depends on how much you pee in 24 hours (your urine output).

You need to measure your fluid allowance every couple of months because the amount that you pee can decrease. If you have any concerns, please talk to your kidney doctor or nurse.

The following table sets out useful measurements to calculate your fluid allowance:

Here are some tips to help you limit the amount of fluid that you drink:

It is important to include "wet" foods in your fluid allowance, such as soup, custard, gravy and yoghurts.

The following table gives you an idea of how much fluid there is in different foods:

You also need to include any oral nutritional supplements that you are prescribed as part of your fluid allowance.

Reducing the salt in your diet

Eating too much salt can raise your blood pressure and make you feel thirsty. This makes it difficult to control the amount that you drink.

If you reduce the amount of salt in your diet, this will make it much easier to manage your fluid levels.

Reading food labels

Many food products have a traffic light label with red, amber and green colours. These colours help you to identify whether the food has a high, medium or low amount of certain nutrients in a 100g portion. You can then make healthier choices.

For foods that do not have a traffic light label, here is a guide for checking the salt content:

Here are some tips to reduce the salt in your diet:

When you start to eat less salt, your taste buds will get used to this in a few weeks.

Controlling the potassium in your diet

Potassium is a mineral that you need for your nerves and muscles to work. Healthy kidneys control the level of potassium in your blood. 

When your kidneys no longer work, extra potassium can build up in your blood. This can be dangerous because it can cause an irregular heartbeat.

High potassium levels may be caused by:

• eating too many potassium-rich food and drinks
• constipation
• uncontrolled blood sugar levels if you have diabetes
• medicines containing potassium

While on peritoneal dialysis, you need to aim for your potassium levels to be between 4.0 and 5.5mmol/L.

Unlike haemodialysis, peritoneal dialysis is usually a daily treatment. As a result, potassium is less likely to build up to high levels in your blood. This means that most people on peritoneal dialysis can have a less strict diet.

There is no need to follow a low potassium diet, unless your kidney doctor or dietitian has advised you to do this. If you need to have a low potassium diet, your dietitian will give you more detailed advice.

Controlling the phosphate in your diet

Phosphate is a mineral that you need to keep your bones strong and healthy.

Healthy kidneys control the level of phosphate in your blood. When your kidneys no longer work, the phosphate in your blood can build up.

In the short term, a high level of phosphate can cause:

• itchy skin and eyes
• aching muscles
• painful bones

If your phosphate level is high for a long time, this can make your bones weak. They may then break more easily.

The phosphate can also build up in your blood vessels, joints and muscles, and cause them to harden.

You may be advised to reduce the amount of phosphate in your diet.

There is no need to follow a low phosphate diet, unless your kidney doctor or dietitian has advised you to do this. If you need to have a low phosphate diet, your dietitian will give you more detailed advice.