Over 5 percent of people in the United States develop a kidney stone at some point in their lives, reports the National Kidney Foundation. There are two main types of kidney stones: calcium stones and uric acid stones. While genetic predisposition, obesity or infection may cause some kidney stones to develop, others may be directly linked to your diet. In a Harvard Medical School blog, Beth Israel Deaconess Medical Center assistant professor Dr. Melanie Hoenig says kidney stone patients may be able to help prevent further stone development by limiting their intake of certain foods. Ask your doctor for help in designing a balanced kidney stone diet.
Control Your Sodium
Hoenig says that if your diet contains too much sodium, your risk of future calcium-based kidney stones may be increased because a high level of sodium in your body causes the calcium concentration of urine to rise. Limit yourself to no more than 2,300 milligrams of sodium per day. Avoid processed, prepackaged, canned and frozen foods in favor of whole grains, fresh fruits and vegetables, and unprocessed meats. Look for low- or no-sodium brands of bread and dairy products. Do not use salt at the table or when cooking; instead, use herbs, spices, juice, vinegar or sodium-free seasoning mixes to add flavor to your food.
Get Enough Calcium
If you have a calcium-based kidney stone, limiting your calcium intake usually won't help: in fact, it may exacerbate the problem and possibly cause you to become deficient in a vital nutrient. Aim to reach your recommended daily allowance of calcium with low- or nonfat dairy products like milk, yogurt or cheese that are also low in sodium. Adults between ages 19 and 50 -- and men up to the age of 70 -- need 1,000 milligrams of calcium daily, while women over 51 and men over 70 should get 1,200 milligrams per day. Vegans and vegetarians can substitute calcium-fortified plant milks.
Watch Out for Oxalates
Oxalates are compounds found primarily in plant-based foods. If your diet doesn't include enough calcium or consists of too many high-oxalate items, these compounds may build up in your body and contribute to the development of kidney stones. Kidney stone patients should avoid foods with high concentrations of oxalates, including chocolate, nuts, spinach, strawberries, tea, beets, rhubarb and sweet potatoes. If you have calcium oxalate stones, your doctor can help you determine how many high-oxalate foods you can safely include in your daily meals.
A diet that includes too many foods with a high purine content may increase a kidney stone patient's likelihood of developing uric acid-based kidney stones. Limit your consumption of purine-rich foods, including organ meats, seafood such as shrimp and lobster, fish such as sardines or anchovies, processed meats such as bacon or ham, dried beans and legumes, red meat, and certain vegetables like cauliflower, spinach and asparagus. Base your diet on whole grains, low- or nonfat dairy and low-purine fruits and vegetables.
Drink Plenty of Fluid
A kidney stone patient should drink at least eight 8-ounce cups of fluid each day, advises Hoenig. Plain water is best -- at least 50 percent of the fluid you drink per day should consist of water -- though the citrate in citrus drinks like 100 percent orange juice may help prevent the formation of kidney stones. To help you get enough, drink one 8-ounce glass of water every hour. Keep your caffeine consumption to no more than one or two cups of cola, coffee or tea per day.