Diet to help reduce the risk of kidney and ureteric stones

Not drinking enough can increase your risk of kidney stones. You can try to avoid this by aiming to go through 2.5-3 litres each day (5-6 pints). 

Try to spread drinks evenly through the day. Drink more when it is hot, and during and after exercise. 

Drinks to include: 

• Water (ideal).
• Dilute squash or cordial.
• Carbonated water, carbonated drinks (not sugar sweetened).
• Tea and coffee (limit to 4 mugs day due to caffeine content).
• Fruit tea. 

Drinks to limit: 

• Sugar sweetened drinks.
• Dark carbonated drinks (like cola).
• Large volumes of fruit juices (high fructose content). 

You can get an idea of how big your cups/mugs/glasses by using a measuring jug to measure how much they hold. It may be useful to write this down. 

Am I drinking enough

If you are drinking enough, you will make over 2 litres of urine each day. Your urine urine should be colourless to pale straw coloured (1-3 on the chart below). 

Eating too much salt (or sodium) can increase calcium in your urine, and having higher amounts of calcium in your urine may increase your risk of kidney stones. Too much salt in the diet can also reduce something called citrate in your urine, and low citrate may increase your risk of forming stones. It is recommended that you limit salt in your diet to less than 6g each day (about 1 level teaspoon, or about 6 “pinches” of table salt).

Salt in the diet comes in the form of “added salt” and “hidden salt”. Added salt is what we add at the table or in cooking, and hidden salt is what is found in many shop-bought, processed/ manufactured foods. Around 75% of the salt we eat comes hidden in food, so reading food labels is important when trying to limit the amount we eat. Please see our diet sheet on how to reduce salt in the diet (How to eat less salt | North Bristol NHS Trust). 

Although there may be calcium in your stone, it is important that you have calcium in your diet. If you are not getting enough calcium from your diet, your body will take calcium from your bones. Over time this can weaken your bones. 

Aim to include 3-4 of the following high calcium foods each day (700g-1200g calcium per day): 

• Milk: a third of a pint or 200ml.
• Cheese, including cream cheese: 1oz or 30g.
• Yoghurt: 1 individual size pot.

For healthier options, choose lower fat alternatives.

If you use non-dairy alternatives, make sure they contain 120mg calcium per 100g/100ml. 

Eating plenty of fruits and vegetables is good for our health, and people that eat plenty of fruits and vegetables appear to have lower risk of forming kidney stones.

Aim to eat at least 5 portions of fruit and vegetables each day (this does not include potato). 

What is a portion? 

• Fruit: what you can hold in your hand (for example 2 satsumas or 1 apple).
• Vegetables: 2-3 heaped tablespoons.
• Salad: the amount to fill a breakfast bowl. 

Citrus 

Lemons are high something called citrate, and including lemons in your diet may increase the amount of citrate in your urine. Having good amounts of citrate in your urine is linked with a reduced risk of forming kidney stones. 

Ideas to include more citrus fruit: 

• Try squeezing lemon juice onto food (like Mexican, Thai, fish dishes, and salads).
• Squeeze lemon juice into water to make it more interesting to drink. 

Eating plenty of fruits and vegetables can also increase the amount of citrate in your urine, so it is another reason to reach for at least 5 portions of fruit and vegetables each day. 

Eating too much protein has been linked with an increased risk of forming kidney stones.

Animal proteins include: 

• Meat (like beef, lamb, pork, minced meat, ham, burgers, sausages).
• Poultry (like chicken and turkey).
• Fish (like cod, tinned tuna, prawns, fish fingers).
• Eggs and cheese. 

Try to limit your proteins of animal protein to healthy eating amounts for example: 

• 60g or 2oz at a snack meal (cold meat/1 large egg in a sandwich).
• 115g or 4oz at a main meal. This amount is about the size of a packet of playing cards. 

Animal protein from cow's milk and yoghurt does not need to be limited unless you eat large amounts (more than 4 high calcium foods each day). 

Plant based proteins do not seem to increase the risk of kidney stones. Here are some ideas to include more plant-based proteins: 

• Use lentils and beans as the protein source for meals.
• Reduce meat portion and pad meals out with beans or pulses.
• Include meat free days in the week.

If you buy over the counter vitamins, do not take more than the reference nutrient intake (RNI) or dietary reference value (DRV). The label on the the bottle will will you what percentage of RNI or DRV the vitamin will give you. 

Try to avoid any that give you more than 100%. 

Losing weight if you are overweight may reduce your risk of forming kidney stones. Eating healthily and having smaller portions can help with weight loss. Being more active is also important. 

Keeping good control of your blood sugar levels may help you to reduce your risk of forming kidney stones. Make sure you attend your diabetes appointments at your surgery or hospital. 

Overview | Renal and ureteric stones: assessment and management | Guidance | NICE

EAU Guidelines on Urolithiasis - Uroweb

Kidney Stones: Medical Management Guideline - American Urological Association