Renal - A Guide to Healthy Eating for People with Kidney Disease

Understanding your kidneys

Healthy kidneys

• Control the level of substances and water in the body, which come from what we eat and drink
• Remove waste products such as urea and creatinine from the body and pass these into the urine
• Remove excess potassium, salt and water from the body
• Help to control blood pressure
• Control calcium and phosphate in the blood, which keeps the bones, blood vessels and heart healthy
• Produce a hormone called erythropoietin (EPO), which prevents anaemia

What symptoms may I have?

If your kidneys are not working properly, you may experience some of the following:

• Feeling tired due to anaemia and the build-up of waste products
• Loss of appetite, nausea and vomiting
• High blood pressure, ankle swelling (oedema) or shortness of breath due to extra fluid and salt in your body
• Itching from high levels of phosphate and urea
• High potassium levels which can affect the rhythm of your heart

How can I help?

Changes to your diet can often help the treatment and complications of kidney disease. Your medication will also help.

Dietary information on television, the internet and in magazines is NOT the best advice for people with kidney damage. A healthy diet for people with kidney damage often looks very different to a general healthy diet.

Changing your diet is not easy. If your kidney disease progresses your dietary needs will alter. Do not be surprised if the dietary advice you are given changes with time as advice will be individualised to you depending on your blood test results, the stage of your kidney disease and the treatment that you are receiving.

Always ask the Renal Dietitian if you have any dietary questions.

What should I eat?

It is important to include a variety of different foods every day. However, some foods may need to be limited to help control the level of waste products in your blood and reduce the work of your kidneys.

Your diet should be:

• Moderate in protein
• Balanced in energy
• Low in salt
• Moderate in potassium and phosphate 

Protein

Protein is needed for growth and repair of all body tissues and for protecting you from infection.

Protein is found in meat, chicken, fish, eggs, cheese, milk and pulses. If you restrict any of these foods e.g. you are a vegetarian, you should discuss your protein intake with a Renal Dietitian.

Too little protein in your diet can lead to malnutrition but too much can cause a build up of waste products in your blood.

The amount of protein you need to eat depends on your body size and kidney function.

Try to include no more than 2 portions of protein rich food each day in addition to your milk allowance:

• 1 small portion for your snack meal, e.g. 25-50g (1-2oz) cooked meat or chicken, cheese, tuna, 1-2 eggs
• 1 average portion for your main meal, e.g. 100-150g (4-6oz) beef, lamb, pork, chicken, turkey, fish, lentils, beans, Quorn, textured vegetable protein

Ask your dietitian if you want more information about the amount of protein you should have in your diet.

Energy (calories)

Energy (calories) are needed for your body to use protein effectively and to help maintain your weight. Energy comes from both carbohydrates (starches and sugars) and fats.

Always include some starchy food at each meal for example, bread, breakfast cereals, pasta, rice, noodles or potatoes.

Potatoes, sweet potatoes, and yams are high in potassium and may need to be boiled. Once boiled they can be mashed, roasted, chipped or sautéed.

Fat

Fat is a good source of energy. Try to use olive, rapeseed, corn, and sunflower oils and margarines made from these oils, rather than butter and lard.

Healthy weight

Healthy weight is measured by Body Mass Index (BMI). Your BMI is calculated from your weight and height, a healthy BMI range is between 20 and 25. Being a healthy weight can help to control your blood pressure and reduce the risk of damage to your kidneys.

Poor appetite

If your appetite is poor or you are losing weight you should always discuss this with your Renal Consultant, Specialist Nurse, or Dietitian.

The Renal Team will look at your symptoms and current diet and suggest changes to your dietary pattern, foods or medications.

You may need a nutritional supplement which the Renal Dietitian can request from your G.P.

Top tips if you have a poor appetite

• It is important to have small regular meals and snacks in between. Remember you can also go back for seconds
• Try to eat something every 2-3 hours even if it is only something small
• Have puddings or desserts at least once a day - if you are too full after a meal wait 30 minutes before having dessert
• Take drinks after meals rather than before or with meals to avoid feeling too full or bloated
• Make the most of ‘good days’ or times during the day when you feel more like eating

Salt

Salt is also called sodium chloride. Sodium is a mineral found naturally in our bodies and is important in controlling fluid and blood pressure.

Sodium is also found naturally in a variety of foods, and more is added by food manufacturers.

Why do I need to reduce salt in my diet?

Your body cannot get rid of salt when your kidneys are not working properly. This may lead to fluid retention, oedema, breathlessness, and increased blood pressure.

Eating less salt can help control high blood pressure and fluid retention and reduce your risk of heart disease and strokes.

Everyone needs some salt in their diet but most of us eat far more than is necessary.
 
Adults should aim to eat less than 6g of salt per day. This is about one teaspoon but remember 75% of this is already hidden in manufactured foods.

Top tips to reduce salt

• Try to prepare more meals from fresh ingredients
• Avoid adding salt to your food at the table
• Use food labels to help choose lower-salt ingredients and meals
• Choose alternatives to salt when cooking. Flavour foods with herbs, spices, pepper, vinegar, lemon juice, mustard
• If using stock cubes, one cube should serve a minimum of 4 portions and no extra salt should be added to the dish
• Avoid salty snacks e.g. salted nuts and crisps
• Use reduced salt gravy granules and plain water for gravy with meat juices if available, do not use potato or vegetable water
• Try to have fresh foods whenever possible. If you do have ready meals and sandwiches, choose meals with less than 0.6g sodium per meal, that’s 1.25g salt (see below)
• For individual foods e.g. sauces and soups choose foods with less than 0.3g sodium per serving, that’s 0.75g salt
• If using tinned vegetables in brine, drain off the liquid, rinse and reheat in fresh water with no added salt

*Do not use salt substitutes in place of salt in your diet. These are high in potassium and are not recommended for people with kidney disease*.

Potassium

Potassium is a mineral found in a wide variety of food and drinks.

Everyone has potassium in their blood and any excess is passed in the urine. When your kidneys are not working properly the amount of potassium in your blood can rise too high.

Potassium can quickly build up and cause changes to your heartbeat.

Avoiding food and drinks high in potassium can help prevent this. Reducing potassium in your diet should be discussed with a Renal Dietitian to ensure your diet contains adequate nutrients.

Phosphate

Phosphate is also a mineral found in the food you eat and is needed to maintain strong and healthy bones.

Your kidneys help to control the phosphate level in your blood. You may need to restrict your intake of phosphate containing foods and fluids because high blood levels can cause itching, weakening of your bones and eventually damage to your heart and blood vessels.

Reducing phosphate in your diet should be discussed with a Renal Dietitian to avoid nutritional deficiencies.

Fluid

Continue with your normal fluid intake unless a Renal Doctor or Specialist Nurse advises otherwise. They may ask you to:

• Increase your fluid intake
• Decrease your fluid intake
• Keep to a fluid restriction (a measured volume each day)

Remember as well as your drinks there is also fluid in some foods
e.g. milk puddings, yogurts, jelly, ice, ice cream, ice lollies, porridge, gravy, soup, sauces, curries and casseroles.

If you have been told to drink less fluid it is very important that you follow the advice on salt carefully as salt increases thirst.

Diabetes

If you have diabetes you should still aim to optimise the control of your blood sugars. Not only does this minimise the risk of further complications but it also helps to control your thirst.

Alcohol

Alcohol is usually permitted providing your doctor has agreed, however should only be taken in moderation regardless of kidney problems.

Vitamin and mineral supplements

Please tell your doctor, pharmacist or dietitian if you are taking vitamin supplements and/or herbal remedies.

0161 206 1994
RenalDietitians@nca.nhs.uk

Useful Websites

Kidney Care UK
www.kidneycareuk.org

National Kidney Federation
www.kidney.org.uk

Greater Manchester Kidney Information Network
www.kinet.site/gmkin