‘In excess, even nectar is poisonous’.
– A wise Indian proverb
When I visited the US a decade ago, my western hosts were surprised and perhaps dismayed that I was a hardcore veggie. At a party thrown for me, a very senior American gentleman remarked; “Kid you need more protein to be healthy.”
Respecting his age, I did not retort. But, this is a very common misconception in America since the 1900’s. Americans have traditionally eaten twice the amount of protein that is needed for the body and are not aware of the risks of eating animal protein. Today, a popular diet called the Atkin’s diet encourages high protein and fat intake to lose weight. Excess protein has been linked with osteoporosis, kidney, calcium stones in the urinary tract, and some cancers.
How much protein do we need?
When we were medical students in the 1970’s, we were taught that we needed 1 gram of protein/kg body weight. Thus, a 70kg human being needed about 70 grams of protein per day.
Current recommendations believe that the body loses about 0.34 g of protein per kg body weight per day. With a safety margin added, apparently we need .45 g/kg per day of “ideal” protein to replace what’s lost. With additional safety margins for digestibility and protein quality, our protein requirement is in the neighborhood of .75g/kg, or about 56 grams of protein for a 70 kg man.
We were also taught out of the 20 odd amino acids, the body could synthesize only about 11 of them and the other nine, which had to be got from nutritious sources, were called as ‘essential amino acids.’
It was well known that our protein requirements could change dramatically in illness or injury. Mothers also need more proteins during pregnancy and lactation. It is a common misconception that athletes and other physically active people needed a very high protein intake. It is now understood that, carbohydrates are the best supply the extra energy required for strenuous activity.
Vegetarian Protein is an excellent source:
- Too much protein is harmful because it can shorten life; increase the risk of cancer, heart disease risk, increase the obesity and diabetes, osteoporosis, kidney stress, and lead to indigestion
- High protein-diets bring about temporary weight-loss but at the expense of overall health. Sadly people quickly regain weight once they return to a normal diet
- A varied vegetarian diet with a balance of protein, fats & carbohydrates, and adequate calorie intake provides more than enough protein
- Animal protein is an inferior source of protein as compared to vegetarian sources of protein
- Vegetarian proteins do not include the excess calories from fat and toxic residues, which are found in animal protein and are safe on the kidneys
The problem with High-protein diets:
Diets rich in animal protein can cause osteoporosis, by causing people to excrete more calcium than normal through their urine. Plant-based diets provide adequate protein and also protect against osteoporosis.
Proteins found in meat, poultry and fish are cooked at high temperatures and produce heterocyclic amines and these are carcinogens and are implicated in colon and breast cancer.
A high protein diet puts a strain on the kidney, which results in kidney stones and other kidney problems. Diets high in fat and saturated fat can increase one’s risk of heart disease. High-protein diets often encourage consumption of meat, eggs, and dairy products, which are all high in cholesterol, fat, and saturated fat. That is the reason, why meat based diets are fraught with cardiovascular risks.
For weight loss, it is better to adopt a lifestyle change that includes a low-fat diet of grains, legumes, fruits, and vegetables combined with regular physical activity, instead of relying on a high protein diet.
Being vegetarian is the best:
“The road of excess leads to the palace of wisdom.”
The wise question is how much is enough is the question that begs to be answered now?
As a thumb rule:
- Aim for 5 or more servings of grains each day. This may include 1/2 cup of hot cereal, 1 oz. of dry cereal, or 1 slice of bread. Each serving contains roughly 3 grams of protein.
- Aim for 3 or more servings of vegetables each day. This may include 1 cup of raw vegetables, 1/2 cup of cooked vegetables, or 1/2 cup of vegetable juice. Each serving contains about 2 grams of protein.
- Aim for 2 to 3 servings of legumes each day. This may include 1/2 cup of cooked beans, 4 oz. of tofu. 8 oz. of soymilk, and 1 oz. of nuts.
References and links:
- Position of the American Dietetic Association: vegetarian diets. J Amer Diet Assoc 1997;97(11):1317-21.
- Munoz de Chavez M, Chavez A. Diet that prevents cancer: recommendations from the American Institute for Cancer Research. Int J Cancer Suppl 1998;11:85
- Ornish D, Brown SE, Scherwitz LW. Can lifestyle changes reverse coronary heart disease? Lancet 1990;336:129-33.