The importance of amino acids in a diet
Amino acids are the building blocks for protein and a life necessity for humans and animals. Amino acids are bonded with nitrogen and form proteins and nitrogen is the end product of protein digestion. Amino acids are the primary building blocks of your muscles, bones, enzymes and many hormones. We cannot live without protein and as long as we get sufficient protein from animal and or plant based diets, it is fine.
There are 22 amino acids where eight is classified as essential. The essential amino acids cannot be manufactured by the body and must be supplemented by food and supplements. The non-essential amino acids can be synthesised by the body if all the essential ones are available. Histidine is only essential for infants and children.
Essential amino acids
- Histidine – only essential for infants and children
- Isoleucine
- Leucine
- Lysine
- Methionine
- Phenylalanine
- Threonine
- Tryptophan
- Valine
Non-essential amino acids (can be manufactured by the body)
- Alanine
- Arginine
- Asparagine
- Aspartic acid
- Cycteine
- Cystine
- Glutamic acid
- Glutamine
- Glycine
- Ornithine
- Proline
- Serine
- Tyrosine
How much protein do we need?
The Dietary Reference Intake is 0.8 grams of protein per kilogram of body weight. This amounts to 56 grams per day for the average sedentary man and 46 grams per day for the average sedentary woman.
Different types of protein
1. Complete protein
Complete protein contains all eight essential amino acids and is found in meat, poultry seafood, eggs milk and cheese. Whey is a complete protein. Pea and Rice protein powder are considered complete proteins. Brown rice protein powder is a complete protein.
2. Incomplete protein
Incomplete protein lacks certain essential amino acids and is found in seeds, nuts, peas grains and beans. You can create a complete protein by combining the above with cheese.
Energy value of food
Food |
Energy value |
| Protein | 17 kJ/gram |
| Carbohydrates | 17 kJ/gram |
| Fat | 37 kJ/gram |
| Alcohol | 29 kJ/ml |
Adverse effects of a low protein
- A sluggish metabolism
- Trouble losing weight
- Trouble building muscle mass
- Low energy levels and fatigue
- Poor concentration and trouble learning
- Moodiness and mood swings
- Muscle, bone and joint pain
- Blood sugar changes that can lead to diabetes
- Slow wound healing
- Low immunity
Adverse effects of a high-protein diet followed for an extended time:
- High-protein diets restrict carbohydrate intake so that they can result in nutritional deficiencies or insufficient fibre, which can cause problems such as bad breath, headache and constipation.
- Some high-protein diets include foods such as red meat and full-fat dairy products, which may increase your risk of heart disease.
- A high-protein diet may worsen kidney function in people with kidney disease because your body may have trouble eliminating all the waste products of protein.
