All of the cells in your body need protein because proteins are constantly broken down and replaced by new proteins. Amino acids are the building blocks of protein. Some foods contain complete proteins, and others have incomplete proteins. Complete protein sources contain all of the 20 different amino acids, including the essential amino acids that your body cannot make. An incomplete protein source is one that is missing one or more essential amino acid. A balanced, varied diet will contain sufficient protein and all essential amino acids.
Protein in a Balanced Diet
Eat a varied, balanced diet to get sufficient protein. A balanced diet draws on all food groups such as meat or meat-substitute, vegetables, dairy, grains and fruit. Complete protein sources are animal-based and include meat, fish, milk, cheese and eggs. Large amounts of these protein sources will have negative effects on your health because they also increase your consumption of saturated fats, cholesterol, trace amounts of antibiotics and other toxins. You can also get sufficient protein daily by eating a plant-based diet, but most plants contain incomplete proteins. Eating more than one plant-based protein source, such as beans and rice, will give you all the essential amino acids that you need. Plant-based protein sources are also loaded with fibre and antioxidants, which are essential components of a healthy diet.
Recommended Protein Intake Based on Calories
Determine your recommended daily intake of protein based on your total daily intake of calories. The Institutes of Health's Dietary Reference Intake (DRI) recommends that your daily protein intake be 10 per cent to 35 per cent of your total calorie intake. Some nutritionists such as T. Colin Campbell, author of "The China Study," disagree and believe a healthy protein amount should not exceed 10 per cent of your daily calorie intake.
Recommended Protein Intake Based on Age
Determine your daily recommended protein intake by your age. The Institute of Medicine has established Recommended Dietary Allowances (RDA) for protein for men, women and children at various ages. The RDA for children age 1 to 3 is 13g of daily protein. The RDA increases with age until adulthood. The daily RDA for men (age 19 to 70-plus) is 56g, and for women (age 19 to 70-plus) it is 46g.
These daily amounts are easily achieved because the protein content, for example, of a 85.1gr. piece of meat is about 21g; one cup of dry beans is 16g; one cup of milk is about 8g; and an 227gr. cup of yoghurt is about 11g.
Protein Intake Based on Activity Level
You need more protein if you are more active than the average person. Muscles have a high protein content, and protein enhances muscle development. Whereas the recommendation for the average person is about 0.4g of protein per pound of body weight per day, the recommendation for athletes is 0.8g per pound of body weight. Although some athletes consume huge amounts of protein, protein much higher than 0.8g per pound of body weight does not significantly increase muscle development and might have negative health effects.