Eating a Vegetarian Diet While Living with Kidney Disease

By Joan Brookhyser, RD, CD, CSR

Currently, more than 20 million Americans have impaired kidney function, with an estimated 3 million people being newly diagnosed every year. Chronic Kidney Disease can require huge adjustments, especially with regard to the necessary dietary changes. If you have this disease, the food you eat becomes more important than ever before. Historically, health care professionals have been skeptical about people with kidney disease adhering to a vegetarian diet. However, with careful planning, a vegetarian diet is not only safe but also can be helpful in managing Chronic Kidney Disease. Research shows a vegetarian diet can actually slow down the progression of kidney function decline and other complications associated with this disease.

Nutrition management focuses on decreasing waste product build-up from digested foods, which would normally leave the body as urine. Therefore, the primary goal of diet planning is threefold:

  1. Obtaining the appropriate amount of plant protein to meet protein needs while minimizing waste product build-up in the blood
  2. Maintaining sodium, potassium, and phosphorus balance
  3. Ensuring good nutrition

The following information is meant to be an initial guide to those with early kidney disease (30-90 percent of normal kidney function) who are not receiving dialysis treatments. More careful follow-up is recommended, especially when kidney function decreases below 30 percent or when regular dialysis treatment is required. As always, consult your health provider regarding your individual needs.

QUALITY PROTEIN

People with chronic kidney disease should modify the amount of protein they eat. Since plant proteins are less demanding on kidney clearance, this restriction does not need to be as severe as with animal protein diets. Keeping to 0.8 g of protein per kg body weight is recommended, with approximately two-thirds coming from quality plant protein, such as the sources listed in Table 1 below. For example,

  • Your weight: 132 lbs. or 60 kg (lbs./2.2 = kg)
  • Your total protein needs: 60 x 0.8 = 48 grams
  • Amount needed from quality protein sources: 48 x 2/3 = 32 grams per day

A mixture of these protein sources should be eaten to ensure an adequate balance of all essential amino acids. Soy protein has been shown to be particularly beneficial in minimizing some complications associated with kidney disease. This includes minimizing proteinuria (protein loss in the urine) and hyperfiltration (excess filtering of the kidney, causing more kidney damage).

TABLE 1: Suggested Quality Protein Servings
for Those with Chronic Kidney Disease
Protein Serving Size =
7 g of Protein
Meat analogues
(processed soy foods)
2 ounces
Seitan (wheat gluten)* 1 ounce
Beans, dried cooked 1/2 cup
Tofu 1/4-1/2 cup
Tempeh 1/4 cup
Nut butters 2 Tablespoons
*Though seitan is not particularly high in some essential amino acids, it is a concentrated source of protein. Most renal professionals agree that as long as patients choose from a variety of protein sources and their total protein needs are met, they will also meet their amino acid needs. (Nephron 1996, 74:390-4)

SODIUM, POTASSIUM, AND PHOSPHORUS

Sodium

Sodium is probably the easiest part of a vegetarian diet to restrict, since most vegetarians generally eat fewer concentrated sources of this mineral than non-vegetarians. A low sodium diet helps in controlling high blood pressure, which could further damage your kidneys. Also, a diet low in sodium helps minimize your need for diuretic and high blood pressure medications. To limit sodium in your vegetarian diet, avoid foods such as:

  • Convenience foods, including frozen meals, canned soup, dried soups, miso, or packaged vegetable broths.
  • Soy-based cheeses (also processed dairy cheese).
  • Meat analogues containing more than 350 mg of sodium per serving. This includes such foods as tofu hot dogs, veggie burgers, or other canned or frozen soy products.
  • Salt, soy sauce, tamari sauce, or any spices that contain the words sodium or salt.

Potassium

Many people with kidney disease need to limit concentrated food and beverage sources of potassium. Decline in kidney function and certain medications can help your body to retain potassium. In rare instances, potassium losses will be very high, resulting in a need for more potassium. A routine blood check of this mineral is important to determine how much potassium you need. In general, potassium does not need to be restricted unless kidney function decreases to less than 20 percent. An estimated two-thirds of dietary potassium comes from fruits, vegetables, and juices, so the easiest way to limit this mineral initially, if restriction is needed, will be to restrict fruit and vegetable selections to five servings per day.

A potassium serving size:

  • 1/2 fresh fruit
  • 1/2 cup canned fruit, fruit juice, or vegetable juice
  • 1 cup raw vegetables
  • 1/2 cup cooked vegetables

If this does not decrease your serum potassium to the normal range, try limiting the foods listed in Table 2.

TABLE 2: High Potassium Foods
(To further decrease serum potassium, limit the following items to 1 serving per day.)
Textured Vegetable Protein (TVP) 1/4 cup
Soy flour 1/4 cup
Nuts and seeds 1/4 cup
Dried, cooked beans or lentils 1 cup
Dried, cooked soybeans 1/2 cup
Tomato products 1/4 cup
Potatoes 1/2 cup
Dried fruit 1/4 cup
Tropical fruit (such as guava,
    mango, papaya, passion fruit,
    and pineapple)
1/2 cup
Melons 1/2 cup

Alternative protein selections may be needed to keep potassium levels from getting too high. This will mean using more tofu, tempeh, or seitan to meet protein needs.

Phosphorus

It is beneficial in kidney disease to start limiting high phosphorus foods before the phosphorus level in your blood becomes high. In fact, you will benefit from limiting phosphorus-containing foods when kidney function levels descend to 50 percent or less. The impact of excess phosphorus can occur early on in kidney disease. Too much phosphorus can stimulate your parathyroid gland to pull too much calcium from your bones, ultimately leading to bone disease.

Some plant proteins are high in phosphorus. However, foods such as dried cooked beans and nuts have high phytate (a naturally occurring compound that blocks phosphorous absorption) contents. They usually do not increase serum phosphorus levels when eaten alone. Dairy products are the main source of concentrated phosphorus. For the lacto-ovo vegetarian, this will mean decreasing dairy products to 1 serving or fewer per day. For the vegan, a few other high phosphorus foods, such as soy cheese and soy yogurt, are worth noting. See Table 3 for a list of foods that may be problematic.

TABLE 3: High Phosphorus Foods
(Those with Chronic Kidney Disease
should limit to 1 serving per day.)
Milk 1 cup*
Cottage cheese 2/3 cup
Cheese 2 ounces
Pudding or custard 8 ounces
Yogurt 8 ounces
Soy cheese 4 ounces
Soy yogurt (non-fortified)** 12 ounces
* Non-dairy creamer, rice milk, and up to 2 cups of soymilk per day can be used as a replacement for milk.
** Soy products that are fortified often have added potassium, calcium, and phosphorus. Try to find products that are not fortified since all three of these minerals can easily become elevated in some individuals with Chronic Kidney Disease.

GOOD NUTRITION

It is not uncommon to find that your appetite decreases as kidney disease progresses. This generally happens when kidney function decreases to levels between 20 and 30 percent. Taste changes or nausea can occur, diminishing the desire to eat. Overall, a vegetarian diet is much easier than a non-vegetarian diet to tolerate. Taste problems tend to be worse with meats and other animal protein foods. More concentrated sources of calories and protein may be needed to prevent weight loss if this begins to occur. Some ideas to help:

  • SOY SHAKES: Shakes made with soymilk, tofu, rice milk, and non-dairy frozen desserts.
  • ADDING THE FATS: Using more oils, such as olive oil, peanut oil, or canola oil, in cooking can help increase calories and prevent weight loss. Flax seed oil can also be drizzled on food after it is cooked or mixed with salad dressing.
  • SNACKS: Small frequent meals and snacks may be better tolerated than three larger meals.
  • COLD FOODS: Hot food sometimes causes more nausea. Eating leftovers cold may be better tolerated than warm. Cold snacks using soy cheese and crackers, soy puddings, or soy yogurt may be easier to eat.
  • SWEETS: Even though a high sugar diet is not a first choice for food, at times these foods add calories that are beneficial to avoid losing weight. Some good choices are hard candy and sorbets.

VITAMIN AND MINERAL SUPPLEMENT

High dosages of any vitamins and/or minerals in kidney disease are discouraged since the poor clearance from your kidneys can cause toxic levels in the blood. Therefore, supplementation in kidney disease needs to be treated on an individual basis. Most people will require a water-soluble vitamin (vitamins B, including B12, and C) without the fat-soluble vitamins, D, A, K, or minerals. Mineral level will need to be checked individually to determine if a supplement is needed. Vitamin E also is used on an individual basis but is seen to possibly have benefit in kidney disease treatment.

WHERE TO TURN FOR FURTHER HELP

It is best to be followed by a nephrologist and a registered dietitian who is familiar with vegetarianism for optimum nutrition planning. Together, these professionals can help manage kidney disease while assisting in appropriate vegetarian food selections. The following organizations can help in locating a dietitian who works with vegetarians:

Joan Brookhyser has been a registered dietitian for 25 years, specializing in kidney disease for the past 20 years and more specifically vegetarianism in the last 10 years. She is board certified in renal nutrition (CSR) and often speaks on this topic and vegetarianism. She has been a vegetarian for 10 years.

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