1) Protein is a major component in most cellular structures. Keratin and collagen are structural proteins that are located in the hair, nails, skin, muscles, bones, connective tissue and cellular walls.
2) Aids the body in most of its physiological functions. Some of these functional proteins include antibodies, enzymes, hormones, and neurotransmitters.
3) Energy-Some amino acids will turn into carbohydrates and used as energy. They can convert into glucose, fatty acids, and ketones.
The controversy arises because a diet with a high protein can have negative affects on the body, and subsequently a diet too low can also have negative impact. These are the reasons why:
Your body can only utilise a certain amount of protein at a time. Excessive protein consumption can lead to disease of the kidneys and liver. The liver is where these amino acids split up into groups; there is an amino group and an acid group. The amino group converts to ammonia then urea. Excessive amounts of urea can cause kidney damage. The acid group will convert to carbohydrates to be utilised as fuel. This can ultimately lead to an increase in overall body fat. The presence of such acids also disrupts the body’s alkalinity and robs the bones of calcium.
Protein deficiency can be very serious; in extremes, it can even be fatal. Protein deficiency causes abnormal growth and development of tissues. For adults protein deficiency symptoms include depression, mental sluggishness, resistance to disease and illness diminishes. For children protein deficiency can seriously prevent a child from growing to their potential mental or physical capacity. In extremely malnourished societies there is a disease present known as Kwashiorkor, symptoms include loss of hair pigment, severe swelling of the joints, and stunted mental and physical growth. This disease can also be terminal.
The amount of protein needed depends on bodyweight and activity level, an average is one gram per kilo of bodyweight. Body builders will eat up to 2 gram per kilo of body weight. Having muscle burns calories, and protein is the key component of muscle, that is why a high protein diet can aid in weight lose.
Amino acids have two qualifications, essential and non-essential. You obtain essential amino acids through your diet, as the body cannot make these on its own. They are essential in the fact that your body needs them to synthesise the remaining amino acids.
A high protein food that also contains a sufficient amount of all eight of the essential amino acids is called a complete protein. The presence of all the essential amino acids enables the body to produce the remaining amino acids, therefore making this food a complete protein source. Complete Protein foods are meat, fish, eggs, dairy, soya, and quinoa.
An incomplete protein is a food that is deficient in two or more essential amino acids. You should combine these foods with other incomplete proteins to obtain a sufficient amount of all of the essential amino acids, so the remaining amino acids are synthesised. Most vegetables fall into this category.
| PROTEIN FOOD | SERVING SIZE | CALORIES | PROTEIN (g) | CARBS (g) | FAT (g) |
|---|---|---|---|---|---|
| Beef - Ground Lean | 113 g (4 oz) | 237 | 21 | 0 | 17 |
| Beef - Top Round | 113 g (4 oz) | 204 | 24 | 0 | 12 |
| Cheese - Cheddar - Fat Free | 1 slice | 31 | 5 | 2 | 0 |
| Cheese - Cottage - Fat Free | 113 g (4 oz) | 96 | 19.5 | 2 | 0.5 |
| Chicken Breast | 113g (4 oz) | 120 | 26 | 0 | 1.5 |
| Egg Whites | _ cup | 31 | 6 | 1 | 0 |
| Egg - Whole | 1 | 80 | 7 | 0 | 5 |
| Egg Substitute | _ cup liquid | 31 | 6 | 1 | 0 |
| Ham - Sliced lean | 56 g (2 oz) | 54 | 9 | 1 | 1.5 |
| Milk - Fat Free | _ cup dry | 81 | 8 | 12 | 0 |
| Protein Powder ** | 28 g (1 oz) | 110 | 22 | 1 | 1.5 |
| Protein Cereal ** | _ cup | 120 | 8 | 28 | 1 |
| Salmon - Canned | _ cup | 94 | 12 | 0 | 5 |
| Tofu - Low Fat | 85 g (3 oz) | 35 | 6 | 1 | 0.5 |
| Tuna - Light | 85 g (3 oz) | 99 | 22 | 0 | 1 |
| Tuna - White | 85 g (3 oz) | 108 | 20 | 0 | 3 |
| Turkey - Ground | 113 g (4 oz) | 178 | 22 | 0 | 10 |
| Turkey - Breast Tenderloin | 113 g (4 oz) | 110 | 25 | 0 | 0.5 |
New Optimum Nutritional Bible- Patrick Holford
100% Health- Patrick Holford
Nutrition for Dummies- Carol Anne Rinzler
A Holistic Guide to Anatomy & Physiology- Tina Parsons
Premier Nutrition for Health and Fitness Manual