Where do get your protein?
The Truth: All plant foods contain all the essential amino acids, which are the building blocks of proteins. The essential amino acids are called ‘complete proteins’ and called essential because the body does not produce them and must be obtained from our diet. For example, broccoli contains 45% protein from its calories and beans contain 23% to 54% depending on the variety.
As long as one is eating a variety of plant foods in sufficient quantity to maintain one’s weight (enough calories), the body gets plenty of protein. Plants are the only foods eaten by elephants, horses, and hippos, and all three have no trouble growing all the muscle, bone, and tissue they need.
Humans Require Very Little Protein
Without sufficient protein from your diet, your body would be in trouble – but, aside from starvation, this never happens. Yes, a little protein is good, but more is not better. Protein consumed beyond our needs is a health hazard that can be as devastating as excess dietary fat and cholesterol.
The World Health Organization (WHO) recommends that men and women obtain 5% of their calories as protein. This would mean 38 grams of protein for a man burning 3000 calories a day and 29 grams for a woman using 2300 calories a day. This quantity of protein is impossible to avoid when daily calorie needs are met by unrefined starches and vegetables. For example, rice alone would provide 71 grams of highly useable protein and white potatoes would provide 64 grams of protein. The body only needs approximately 30-60 grams/day.
Our greatest time of growth—thus, the time of our greatest need for protein—is during our first 2 years of life—we double in size. At this vigorous developmental stage our ideal food is human milk, which is 5% protein. Compare this need to food choices that should be made as adults—when we are not growing. Rice is 8% protein, corn 11%, oatmeal 15%, and beans 27%.8
Unlike fat, protein cannot be stored. Consumption in excess of our needs overworks the liver and kidneys, and can cause accumulation of toxic protein byproducts. Once the body’s needs are met, then the excess must be removed. The liver converts the excess protein into urea and other nitrogen-containing breakdown products, which are finally eliminated through the kidneys as part of the urine. These unneeded amino acid wastes (proteins) can injure the structures of the kidneys, and over time diets high in protein may promote the development of kidney stones and other health issues such as bone loss, osteoporosis, kidney damage, immune dysfunction, arthritis, cancer promotion, and low-energy. In fact, the recommended diet by the medical community for chronic kidney diseases is a low-protein diet which can be met with whole food, plant-based diet.
Unfortunately, almost everyone on the typical Western diet is overburdened with protein. The public has almost no awareness of problems of protein overload, but scientists have known about the damaging effects of excess protein for more than a century.
Proteins Intake Varies Worldwide
The healthy active lives of hundreds of millions of people laboring in Asia, Africa, and Central and South America on diets with less than half the amount of protein eaten by Americans and Europeans prove that the popular understanding of our protein needs is seriously flawed.
** The McDougall Program is the protocol I follow in my nutrition practice.
1) J Pennington. Bowes & Church’s Food Values of Portions Commonly Used. 17th Ed. Lippincott. Philadelphia- New York. 1998.
2) The December 2003 McDougall Newsletter: A Brief History of Protein: Passion, Social Bigotry, and Enlightenment.
3) The January 2004 McDougall Newsletter: Protein Overload