Protein is one of the three macronutrients that provide calories (energy) to our body (carbohydrates and fats are the other two). One gram of protein supplies four calories of energy. It is recommended that we get 20% – 35% of our calories from protein, with 30% appearing to be the ideal target, especially for weight loss.
Protein Required for A 2000 Calorie Diet
2000 calories X 30% protein = 600 calories of protein
600 calories/4 calories per gram = 150 gm of protein per day
Protein builds, maintains and repairs tissues and is found in every cell, tissue and organ in the human body. The protein in our bodies is constantly being broken down and replaced.
Our body requires protein for:
- Growth/building muscle (especially important for children, teens, and pregnant women
- Tissue repair/wound healing
- Immune function/fighting infections
- Making essential hormones and enzymes
- Preserving lean muscle mass
- Energy when carbohydrates aren’t available
The protein in food is made up of 20 standard amino acids. Our bodies can synthesize eleven of these amino acids, but, the other nine must be provided by the diet and therefore are called “essential”.
Foods from animal sources contain all nine of the essential amino acids in sufficient amounts. Most plant foods contain all nine amino acids, but, some are deficient in one or more of the amino acids. It was once thought that vegetarians had to take special care to combine foods from plant sources at each meal to make a complimentary amino acid composition (“complete proteins”). This is unnecessary. A plant-based diet that includes a variety of unprocessed starches (such as rice, grains, potatoes and beans), vegetables and fruits each day, supplies all the amino acids in excess of what is required for excellent health. Research indicates that amino acids will compliment each other if they are consumed within a 24-hour period.
John McDougall, MD, in his article in the American Heart Association Journals titled “Plant Foods Have a Complete Amino Acid Composition“, stated “…a careful look at the founding scientific research and some simple math prove it is impossible to design an amino acid–deficient diet based on the amounts of unprocessed starches and vegetables sufficient to meet the calorie needs of humans. Furthermore, mixing foods to make a complementary amino acid composition is unnecessary.”
Amino Acid by Wellcome Images