Clinics & Inpatient Care Units

Kidney Stone Prevention Clinic

Nutrition tips

Calcium Stones
  • Aim for a healthy body weight
  • Drink lots of fluid
  • Cut back on high salt foods
  • Do not follow a high protein diet
  • Avoid foods very high in oxalate
  • Eat dairy products with your meals

The foods you eat and fluids you drink can affect your risk of forming more kidney stones. Making simple changes to your diet can help prevent more kidney stones from forming.

  1. If you are overweight, try to aim for a healthy body weight.

If you are overweight, losing weight can help lower your risk of forming more kidney stones. It will also have positive benefits for your cholesterol, blood pressure and blood sugar.

If you are not sure if you are at a healthy body weight, use the Body Mass Index (BMI) calculator. Your goal is to have a BMI between 19 and 25, which is the “healthy range”. If your BMI is greater than 25, you can make some changes to your eating habits to help lose weight.

Try to add some simple changes as recommended by registered dietitians at St. Michael’s Hospital:

If you would like to join a weight loss program, use this checklist to make sure the program is safe and helps you reach your goals.

  • Stresses a healthy eating plan
  • Includes daily physical activity
  • Gives you personal support from a group, buddy or dietitian
  • Does not deprive you of the foods you enjoy
  • Has a system to help you keep track of what you eat and drink
  • Recommends a gradual weight loss of one to two pounds per week until a healthy weight is reached
  • Includes a maintenance program for keeping off weight.
  1. Drink lots of fluid.

Drink lots of water and other fluids to prevent more kidney stones from forming.  This will dilute your urine and help to flush crystals from your body.  Try to drink 2.5 to 3 litres (8-12 glasses) of water every day. Drink more water on hot days, or when you are physically active. However, if your doctor tells you to restrict your fluid intake for other medical reasons, it is important to follow their advice.

Adding lemon juice to your water can help prevent kidney stones. Add ½ cup lemon juice to 2 litres (8 cups) water and drink it throughout the day.

Most of your fluid intake should come from water. You can also drink milk and herbal teas. Aim to have no more than one serving of coffee, fruit juices, or black tea each day. Try to avoid sweetened drinks, such as soda, fruit punch, iced tea and hot chocolate. Avoid almond milk and grapefruit juice, as these will increase your risk of forming stones.

If you have trouble drinking this much water each day, try to make it a regular part of your schedule:

  • Drink a large glass of water with every meal
  • Carry a refillable water bottle around with you throughout the day
  • Take your medications with a large glass of water
  • Set a reminder on your watch or on your cell phone to drink water every few hours.
  1. Cut back on high salt (sodium) foods.

Salt (sodium) is essential for your body to function, but most people eat too much salt. Limiting the amount of salt in your food is an important way to help lower your risk of forming kidney stones.

Try not to add salt when you are cooking or eating. Instead of using salt to flavour your food, try herbs, spices, or low sodium seasonings (i.e. Mrs. Dash).

Read the Nutrition Facts Panel for all foods you buy at the grocery store. Try to choose foods that contain less than 15 per cent daily value of sodium. Foods that say “sodium free” or “no salt added” will have much less salt than foods that say “lightly salted” or “reduced salt”.

Avoid eating at restaurants and food courts as much as possible. Many restaurants now offer nutrition information for their menu items. Check how much sodium is in the food you plan to order. If nutrition information is not available, ask for your foods to not be salted.

For more information on sodium:

  1. Do not follow a high protein diet.

Eating too much protein from animal sources is linked to forming more kidney stones. It will increase the levels of uric acid and calcium in your urine, which makes your urine acidic. High protein diets (such as the Atkins diet or Paleolithic diet) are not suitable for people with kidney stones.

Vegetarian proteins (such as beans and lentils) are healthier options than animal proteins.

Some types of animal proteins are more harmful for kidney stone formation.  Try to eat these foods no more than once per month:

  • Anchovies, sardines, and herring
  • Mussels and scallops
  • Organ meats (for example, liver, kidney and sweetbreads)
  • Wild game
  • Goose

For your day-to-day eating, choose lean proteins (for example, poultry and fish). Your portion size of animal protein at each meal should be no bigger than 75 grams or 2 ½ ounces. Do not eat animal protein at more than one or two meals each day.

  1. Avoid foods very high in oxalate.

Oxalate is a compound found naturally in plant foods (fruits and vegetables). Oxalate can bind to calcium in the kidney, causing kidney stones to form.

Oxalate is naturally found in very healthy foods. For this reason, it is important to not follow an extremely low oxalate diet. Instead, try to eat high oxalate foods less often, and in small portion sizes.

Vitamin C supplements are converted to oxalate in your body. Do not take vitamin C supplements.

See the charts below for lists of lower and higher oxalate fruits and vegetables. Other high oxalate foods to avoid include:

  • Almonds and almond milk
  • Cashews
  • Textured soy products (i.e. soy burgers, soy hot dogs, soy protein powder)
  • Cocoa powder
Lower oxalate vegetables
(eat daily)
Higher oxalate vegetables
(eat less often)
Alfalfa sprouts Bamboo shoots
Artichokes Beets and beet greens
Asparagus Okra
Bok choy Olives
Broccoli Parsnip
Brussels sprouts Potatoes
Cabbage Rutabaga
Carrots Spinach (extremely high oxalate)
Cauliflower Turnip
Celery Yams
Chili peppers  
Collard greens  
Corn  
Cucumber  
Endive  
Green pepper  
Kale  
Lettuce  
Mushrooms  
Mustard greens  
Onion  
Peas  
Radish  
Scallions  
Sea vegetables  
String beans  
Sweet potatoes  
Tomato  
Yellow squash  
Zucchini  

Lower oxalate fruits
(eat daily)
Higher oxalate fruits
(eat less often)
Apple Avocados
Apricot Dates
Banana Grapefruit
Blackberries Kiwi
Blueberries Raspberries
Cantaloupe Rhubarb (extremely high oxalate)
Cherries  
Cranberries  
Grapes  
Honeydew melon  
Lemons  
Limes  
Mango  
Nectarine  
Papaya  
Peaches  
Pears  
Pineapple  
Raisins  
Strawberries  
  1. Eat dairy products with your meals.

Research has shown that a diet that contains dairy products will help prevent kidney stones. Dairy products help bind oxalate in your intestines and prevent oxalate from being absorbed by your body.

Try to eat or drink dairy products at breakfast, lunch and dinner. Try to have one dairy serving per meal.

Some examples of one serving of dairy:

  • 250mL or 8oz white milk
  • 175 g or ¾ cup yogurt or kefir
  • 50g or 1 oz cheese

If you are lactose intolerant, choose lactose-free dairy products. You can also use dairy products made with sheep milk or goat milk as these are lower in lactose.

If you would like more information on nutrition for kidney stone prevention, ask your health care provider if you can attend the Nutrition for Kidney Stone Prevention group class.

Uric Acid Stones
  • Aim for a healthy body weight
  • Keep good control of your blood sugars
  • Drink lots of fluid
  • Cut back on high salt foods
  • Do not follow a high protein diet

The foods and fluids you take can affect your risk of forming more kidney stones. Making simple changes to your diet can help prevent more kidney stones from forming.

  1. If you are overweight, try to aim for a healthy body weight.

If you are overweight, losing weight can help lower your risk of forming more kidney stones. It will also have positive benefits for your cholesterol, blood pressure and blood sugar.

If you are not sure if you are at a healthy body weight, use the Body Mass Index (BMI) calculator. Your goal is to have a BMI between 19 and 25, which is the “healthy range”. If your BMI is greater than 25, you can make some changes to your eating habits to help lose weight.

Try to add some simple changes as recommended by registered dietitians at St. Michael’s Hospital:

If you would like to join a weight loss program, use this checklist to make sure the program is safe and helps you reach your goals.

  • Stresses a healthy eating plan
  • Includes daily physical activity
  • Gives you personal support from a group, buddy or dietitian
  • Does not deprive you of the foods you enjoy
  • Has a system to help you keep track of what you eat and drink
  • Recommends a gradual weight loss of one to two pounds per week until a healthy weight is reached
  • Includes a maintenance program for keeping off weight.
  1. If you have diabetes, keep good control of your blood sugars.

If you have diabetes or pre-diabetes, keeping your blood sugars within a healthy range is important to prevent uric acid kidney stones.

Follow the advice of your doctor or diabetes education team.

For help making lifestyle changes to manage your diabetes, you can attend a Diabetes Education Centre free of charge.  A nurse and dietitian who specialize in diabetes care can help you with lifestyle changes to manage your blood sugars. Find a Diabetes Education Centre near you.

  1. Drink lots of fluid.

Drink lots of water and other fluids to prevent more kidney stones from forming.  This will dilute your urine and help to flush crystals from your body.  Try to drink 2.5 to 3 litres (8-12 glasses) of water every day. Drink more water on hot days, or when you are physically active. However, if your doctor tells you to restrict your fluid intake for other medical reasons, it is important to follow their advice.

Adding lemon juice to your water can help prevent kidney stones. Add ½ cup lemon juice to 2 litres (8 cups) water and drink it throughout the day.

Most of your fluid intake should come from water. You can also drink milk and herbal teas. Aim to have no more than 1 serving of coffee, fruit juices, or black tea each day. Try to avoid sweetened drinks, such as soda, fruit punch, iced tea and hot chocolate. Avoid almond milk and grapefruit juice, as these will increase your risk of forming stones.

If you have trouble drinking this much water each day, try to make it a regular part of your schedule:

  • Drink a large glass of water with every meal
  • Carry a refillable water bottle around with you throughout the day
  • Take your medications with a large glass of water
  • Set a reminder on your watch or on your cell phone to drink water every few hours.
  1.  Cut back on high salt (sodium) foods

Salt (sodium) is essential for your body to function, but most people eat too much salt. Limiting the amount of salt in your food is an important way to help lower your risk of forming kidney stones.

Try not to add salt when you are cooking or eating. Instead of using salt to flavour your food, try herbs, spices, or low sodium seasonings (i.e. Mrs. Dash).

Read the Nutrition Facts Panel for all foods you buy at the grocery store. Try to choose foods that contain less than 15 per cent daily valueof sodium. Foods that say “sodium free” or “no salt added” will have much less salt than foods that say “lightly salted” or “reduced salt”.

Avoid eating at restaurants and food courts as much as possible. Many restaurants now offer nutrition information for their menu items. Check how much sodium is in the food you plan to order. If nutrition information is not available, ask for your foods to not be salted.

For more information on sodium:

  1. Do not follow a high protein diet.

Eating too much protein from animal sources is linked to forming more kidney stones. It will increase the levels of uric acid and calcium in your urine, which makes your urine acidic. High protein diets (such as the Atkins diet or Paleolithic diet) are not suitable for people with kidney stones.

Vegetarian proteins (such as beans and lentils) are healthier options than animal proteins.

Some types of animal proteins are more harmful for kidney stone formation.  Try to eat these foods no more than once per month:

  • Anchovies, sardines, and herring
  • Mussels and scallops
  • Organ meats (for example, liver, kidney and sweetbreads)
  • Wild game
  • Goose

For your day-to-day eating, choose lean proteins (for example, poultry and fish). Your portion size of animal protein at each meal should be no bigger than 75 grams or 2 ½ ounces. Do not eat animal protein at more than one or two meals each day.

If you would like more information on nutrition for kidney stone prevention, ask your health care provider if you can attend the Nutrition for Kidney Stone Prevention group class.