Facts for Low-Protein Diets

Protein is essential for good nutrition, and is second only to water in our body's composition. We need it for growth and tissue maintenance. Proteins are made up of 22 different amino acids; 14 we make ourselves, and eight are essential in our diet. Complete proteins contain all the essential amino acids, and include meat, fish, eggs, and dairy products. All plants contain protein, but in lower levels than animal products, and are considered incomplete proteins.

Daily Protein Requirements

• Protein foods include meat, dairy, and legumes.

  Protein requirements for healthy people are based on age, sex and level of physical activity. The USDA recommends that adults aged 19 and over eat 5 to 6.5 oz. per day. For a 132 lb. 40-year old sedentary female, 46 g of protein is recommended per day, or 0.8 g protein per kg of body weight. The average American gets about one to 1.5 g/kg per day. The World Health Organization recommends 0.45 g/kg per day. People with liver or kidney disease may be prescribed low protein diets, as these organs lose their ability to process proteins.

Watch Your Serving Sizes

• It's easy to eat too much protein.

  The USDA Food Pyramid lists one small half-chicken breast as 3 oz., but the chicken breast halves in the grocery store average 6 to 8 oz. each, cooked. One small hamburger patty is also listed as equal to a 3 oz. serving size, but burgers are usually 1/3 to 1/2 lb. in a restaurant. Add some yogurt or an egg with breakfast, a turkey sandwich for lunch, a handful of peanuts for a snack, and a woman aged 31 to 50 has eaten almost three times her daily allotment for protein.

Problems with Protein

• Eating too much protein can put stress on the kidneys and lead to decreased kidney function. Animal protein is high in calories and saturated fat, so if you're watching your weight or cholesterol, eating too much can lead to weight gain and higher cholesterol levels. T. Colin Campbell, PhD, found that excess animal protein increases the chance of some cancers and also increases the amount of calcium excreted in the urine, which could lead to osteoporosis. Eating too little protein can lead to poor nutrition, muscle loss, increased chance of infection and the inability to repair wounds.

Low Protein Diets and Kidney Disease

• In the first stages of chronic kidney disease, the kidneys lose their ability to process proteins and other compounds, which can lead to toxic levels of urea and nitrogen buildup in the bloodstream. Protein is detected in the urine. To decrease the stress on the kidneys, a diet of 10 to 15 percent, or no more than 0.6 to 0.8 g/kg total protein per day is recommended. Phosphate can also cause problems for kidney patients, and it is found in high protein foods. Your doctor or dietitian can design a diet right for you.