Proteins are the basic elements of all animal tissue and about 17% of our bodies are made up of proteins, it is used to maintain our muscles and repair damaged cells it is also a source of energy. White spots on nails and brittle hair are often good indicators of protein deficiency and serious deficiency can lead to serious consequences for the body: these include muscle deterioration and wrinkling of the skin.
Protein is found mainly from animal sources meat, fish, cheese, eggs (egg whites are almost all protein) and milk. Protein is found in pulses such as beans, lentils and nuts and in smaller quantities from vegetables.
An adults recommended intake of protein is about 20% or less of our daily food intake (In industrialised countries the average protein intake is 40%). Some high protein diets can recommend up to 70% protein.
A vegan diet based solely on vegetable protein will be lacking in cystine as the body cannot produce it on its own which will result in nail and hair problems. A vegetarian diet that includes eggs and cheese can be perfectly balanced.