A low-protein diet is any diet in which the protein intake is reduced. Anyone diagnosed with kidney or liver disease may be prescribed a low-protein diet.
In any case, a diet which is especially low in protein should only be undertaken under medical direction.
Why is a low protein diet necessary?
Protein is needed, but can cause problems for diseased organs
Protein is necessary for a healthy body. When protein is metabolized by the liver and digested, urea is produced as a waste product. If the liver is diseased, then food metabolism is compromised.
If the kidneys, which are responsible for excretion of urea, are not functioning properly (renal failure), or if high levels of protein are continually present in the diet, urea builds up in the bloodstream causing loss of appetite and fatigue. A low-protein diet will reduce the workload on these organs.
It is usually the case that serious liver and kidney disease are accompanied by the need to limit salt or sodium intake due to high blood pressure or fluid retention. Table salt (the primary source of sodium in the diet) should therefore be limited, along with other foods with a high sodium content, as an additional feature of the low-protein diet.
Too much protein can worsen your health
It is generally accepted that a healthy person needs 40-60 grams of protein each day to remain in good health. However, it has been reported that the amount of protein typically consumed by people in affluent societies (American diet typically comprises 12-15% protein) may overtax the kidneys – to the extent that up to 30% of kidney function may be lost by the time someone is in their eighties.
High-protein diets for weight loss often recommend 30% or more protein in the daily diet, and in prolonged use can cause serious metabolic changes leading to bone loss and kidney stones!
Reduced protein intake can improve your health
Low protein diets (4-8% protein) are used routinely to treat patients with liver disease, kidney (renal) failure, and disorders involving the urea cycle, the metabolism, and amino acids.
How is a low-protein diet achieved?
Reduce the amount of protein
Some of each type of protein should still be consumed each day from the two main sources:
- Animal products (fish, poultry, eggs, meat, dairy products) – considered high quality or complete protein.
- Vegetable products (breads, cereals, rice, pasta, dried beans) – considered low quality or incomplete protein.
To reduce the amount of protein consumed, protein foods in recipes can be ‘stretched’ (to consume less) or reduced as against more of the low- or non-protein foods (less in proportion), making a smaller amount seem just as satisfying.
- Use thinly sliced meats.
- Fill with salad items like lettuce, alfalfa sprouts, cucumber, chopped celery, apple, parsley or water chestnuts.
- Use lower protein foods (milk substitutes for cream soups, or rice or pasta) to make soups as filling but with less protein.
- Make the main dish of vegetables and grains, and treat meat as the side dish to your meal.
- Use small pieces of meat and more vegetables in kebabs.
- Make fried rice with vegetables and use less meat or shrimp.
- For salads use crisp, fresh vegetables and only a few small strips of meat and egg.
- For casseroles, reduce the amount of meat and increase the starch, pasta or rice. In recipes using soup, use a low sodium mix.
- Use low-protein pastas and breads in the diet.
- For cheeses, use smaller amounts of stronger-tasting cheeses (sharp cheddar, parmesan or romano) for plenty of flavor.
Boost calories to compensate
Decreasing protein in the diet may also mean a reduction in calories. To compensate so as to maintain a healthy weight, increase calories by substituting or adding certain ingredients with minimal protein content, such as:
- Increase heart-healthy fats like monounsaturated vegetable oils (olive, avocado) and mayonnaise-type salad dressings.
- Use candy and sweeteners (hard candy, gum drops, jelly beans, marshmallows, honey, jam and jelly – even sugar (diabetics need medical advice).
- Use canned fruits in heavy syrup.
Sample low protein menu
- Cheerios cereal or equivalent ¾ cup (3g)
- non-dairy creamer ½ cup (0g)
- ½ medium banana (.6)
- orange juice ½ cup (.8g)
- 1 cherry fruit roll up (0g)
- 2 slices white bread (1.6g)
- turkey breast 1 oz/28 g (4.8g)
- lettuce (0g)
- tomato ½ cup (.8g)
- green beans ½ cup (1.2g)
- mayonnaise 3 tsp (0g)
- 1 medium apple (.3g)
- fruit punch 4 fl oz/118 ml (0g)
- lean hamburger 2 oz/56 g (10.5g)
- white rice ½ cup (2.2g)
- broccoli ¼ cup (.9g)
- cauliflower ¼ cup (.6g)
- tossed salad (1.5 cups) with 2 Tbsp ranch dressing (3g)
- pineapple ½ cup (.2g)
Sample low protein menu contains
- Protein: 30.5 grams
- Calories: 1442
- Fat: 48 grams
- Carbohydrates: 237 grams
- Sodium: 1270 mg
- Potassium: 2282 mg
Download the Kidney Diet ebook
- Kopple, J. D., Levey, A. S., Greene, T., Chumlea, W. C., Gassman, J. J., Hollinger, D. L., … & Zimmer, G. S. (1997). Effect of dietary protein restriction on nutritional status in the Modification of Diet in Renal Disease Study. Kidney international, 52(3), 778-791. link
- KOPPLE, J. D., & COBURN, J. W. (1973). METABOLIC STUDIES OF LOW PROTEIN DIETS IN UREMIA: I. NlTEOGEN AND POTASSIUM. Medicine, 52(6), 583-595. link
- Fouque, D., Laville, M., Boissel, J. P., Chifflet, R., Labeeuw, M., & Zech, P. Y. (1992). Controlled low protein diets in chronic renal insufficiency: meta-analysis. BMJ: British Medical Journal, 304(6821), 216. link
- Fouque, D., Laville, M., & Boissel, J. P. (2009). Low protein diets for chronic kidney disease in non diabetic adults. Cochrane Database Syst Rev, 3. link
Last Reviewed: March 28, 2021