Protein, next to water, is the most abundant substance in your body.
The building blocks for proteins are structures known as AMINO ACIDS. There are 22 unique amino acids. Your body can make 13 of these amino acids when it needs them, but the other 9 must be gotten from your food. These 9 amino acids are called the ESSENTIAL amino acids (Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, and Valine). Not that they are more important than the non-essential amino acids, but diet is essentially the only way to get them.
Amino acids are linked together in different combinations to form various length chains. All proteins are made up of one or more of these amino acid chains. To ensure you have all the building blocks, your diet should include COMPLETE proteins (contain all the essential amino acids).
All animal source foods contain complete proteins
NOT all plant-based foods contain all the essential amino acids. Therefore, it is very important to eat a variety of plant foods in order to ensure your protein intake is complete
Protein, no matter how good the quality, will not be used efficiently and will not support growth, without the help of the energy-giving macronutrients: carbohydrates and fats.
Carbohydrates provide 4 calories per gram
Proteins provide 4 calories per gram
Fats provide 9 calories per gram
If the body has to break down its own protein to meet energy needs, a deficiency occurs. Two severe protein deficiency diseases are Kwashiorkor and Marasmus
| PROTEIN DEFICIENCY | |
| Adults | Children |
| May result in lack of vigor and stamina, mental depression, weakness, poor resistance to infection, impaired wound healing, and slower recovery from disease | May cause stunted growth, hair loss or change in hair pigment, lack of vigor and stamina, muscle weakness (including heart muscle), and joint swelling |
It may be necessary to consume extra protein during periods of excess stress or injury such as surgery, hemorrhage, burns, or prolonged illness.
Protein requirements differ according to the nutritional status, age, sex, body size, health status, activity of the individual, pregnancy, lactation, etc…
Optimal protein intake, like optimal caloric intake, can only be approximated and is usually based on the National Research Council’s Recommended Dietary (RDA) guideline of 0.8 grams per kilogram body weight (1 kilogram = 2.2 pounds).
Larger amounts of protein intake may be required under conditions of severe catabolism or protein wastage
Lower amounts of protein intake may be required in cases of acute renal or hepatic insufficiency