People with kidney or liver disease are often put on low-protein diets. Protein takes a toll on the body during digestion and can cause urea to build up. In people with kidney problems, this can cause them to feel sick and experience nausea, loss of appetite and headaches. Most people on a low-protein diet cut down on animal proteins first, because these are the most difficult to digest. You also can cut down on beans, soy and other vegetable proteins.
Lack of Amino Acids
Protein contains all the essential amino acids your body needs. Amino acids play a number of roles in the body, from fighting bacteria to carrying oxygen to the organs and muscles. If you cut down your protein intake, you might not get all the amino acids you need. Lack of the amino acid lysine can cause tiredness, anemia and difficulty concentrating. The amino acid tyrosine, on the other hand, seems to play a role in combating chronic fatigue and depression, according to the website Healing with Nutrition.
Low Iron
Animal proteins are a rich source of heme iron, a type of iron that is easier for the body to absorb. If you cut down your protein intake, you might end up with an iron deficiency, which could lead to anemia. Common symptoms of anemia include fatigue, decreased performance, feeling weak and tired all the time, problems sleeping and decreased immune function.
Loss of Muscle
Protein is essential in the development and maintenance of muscle. If you don’t eat enough protein for a long time, your muscles might start to deteriorate. This can cause weakness, physical fatigue and muscle cramps and aches. Since the heart is also a muscle, a lack of protein can lead to heart problems as well, including arrhythmias.
Protein Needs
Adults need about 0.36 g of protein per pound of body weight. This means a 160 lb person needs 57.6 g of protein per day. People following a heavy exercise program that includes weight training might need more protein.
