Dietary Advice Sheet for Kidney Stones

Kidney Stones Dietary Advice

This page tells you about the dietary advice recommended for people with kidney stones or those likely to develop them. We hope it will answer some of the questions that you or those who care for you may have at this time. It is not meant to replace discussion between you and your surgeon, but as a guide to be used in connection to what is discussed.

Once you have had kidney stones you are more likely to have them again.
You can reduce this risk by making changes in your diet.

What is a kidney stone?

Kidney stones are small, hard lumps – like stones – that can form in your kidneys. Your kidneys ‘clean’ your blood, removing waste products and water to produce urine. Normally, the waste products in your urine are present in very small amounts so they stay dissolved in the fluid. But sometimes they can become solid and form crystals on the inner surface of your kidneys. Over time, these crystals may combine to form a small, hard stone. This is a kidney stone.

Kidney stones can range in size from a grain of sand to a pearl, or even larger. They can be smooth or jagged, and are usually yellow or brown.

Dietary changes

Your body has a tendency to form kidney stones. You can reduce the risk of your body producing kidney stones by changing your dietary habits in the following ways:

Drink a minimum of 4 pints of water per day, enough to keep your urine clear at all times
Eat no more than 2 portions of meat a day (red meat, chicken and fish)
Dairy products are good for you in moderation
Reduce foods containing Oxalates (a chemical that combines with calcium in urine to form the most common type of kidney stone) for example tea, spinach, rhubarb, nuts, berries, chocolate and wheat bran
Reduce your salt intake, on and in your food

This can all be done as part of a healthy balanced diet. You should not need to take vitamin supplements. In particular, calcium tablets and Vitamin C tablets may increase your risk of developing further stones and should not be taken unless prescribed by your doctor. If you are taking these please discuss this with your consultant.

Fluid

Drinking plenty of fluid is the best way to avoid kidney stones. Aim for 2 – 3 litres (4 – 6 pints) per day of liquids such as water or squash.

When you are drinking enough fluid, your urine will be clear rather than yellow in colour. Aim to keep your urine a clear colour at all times, including first thing in the morning.

Taking a glass of water or squash to bed with you if a good idea.

Alcoholic drinks do not increase your risk of kidney stones. You should continue to drink 2 – 3 litres of non-alcoholic fluid per day in addition to any alcoholic drinks.

Animal protein

Reducing the amount of animal protein in your diet can help reduce your risk of kidney stone formation. (Animal protein comes from red meat such as beef, pork, lamb, and also chicken and fish). Protein is an essential nutrient in the diet; therefore, an adequate (no more than 2 portions) intake is important. It is important not to cut out animal protein altogether.

Calcium containing food

You should aim to eat 3 portions of calcium containing foods every day (as part of your meals).

Examples of calcium containing foods are:

Milk 1 glass (200 mls)
Yoghurt 1 pot (125g)
Cheese matchbox size (1oz/25g)
Soya milk calcium enriched 1 glass (200mls)

Oxalate

A chemical that combines with calcium in urine to form the most common type of kidney stone.

A number of foods are high in Oxalate. Too much food containing Oxalate may increase your risk of forming another kidney stone, so where possible, avoid the following foods:

Rhubarb
Most berries
Wheat bran(contained in cereals/bread)
Broccoli
Tea
Spinach
Nuts
Chocolate

Salt

A high intake of salt is associated with kidney stone formation. To reduce the salt in your diet, keep salt in cooking to a minimum (or better, do not cook with salt at all), and do not add salt to cooked food.

Check labels on processed foods and convenience foods as these have a high salt content. Avoid foods which contain more sodium (salt) than 0.5 grams per 100 grams.

Foods high in salt to avoid include:
Meats – Bacon, ham, sausage, corned beef, tongue, luncheon meat, beef burgers, all tinned meats
Fish- Smoked fish or shellfish, kippers, yellow haddock, cockles, prawns, mussels, tinned fish in brine
Spreads – Butter, fish and meat pastes, peanut butter, pâté and sandwich spreads
Snacks – Salty and savoury biscuits, crisps and nuts
Cereals – Breakfast cereals high in salt
Flavourings- Marmite, Bovril, Oxo, gravy, salt, soy sauce, celery salt, garlic salt, horseradish, onion salt, ‘Season all’ and ‘jerk’ seasoning

It is important that you make a list of all medicines you are taking and bring it with you to all your follow-up clinic appointments. If you have any questions at all, please ask your consultant, or nurse. It may help to write down questions as you think of them so that you have them ready. It may also help to bring someone with you when you attend your outpatient appointments.

Authors – Consultant Urologist Panel West Midland Stone Network

Urological Surgeon

Senior Consultant Urological Surgeon Working at Spire Little Aston Hospital, Sutton Coldfield, near Birmingham for last since 2005.

Graduated as a doctor in 1984 and have been working in the NHS for over 30 years. I started my Urology career in 1991 and completed training at the John Radcliffe and Churchill Hospital, Oxford in 2000.