Protein Requirements - What Should You Believe?
Estimates of protein requirements vary. There is so much conflicting advice about protein needs and what the best sources of protein are.
What are normal protein requirements?
It depends a lot on who you are.
and pregnant women need relatively more protein, as does anyone who works really hard physically or exercises a lot. You also need more than normal if you are recovering from surgery or an injury.
A normal, healthy diet should give you about 10% of your calorie intake from protein. That works out at roughly 35g a day for women and 45g a day for men.
This is very rough. Different organisations give different estimates - anywhere between 2.5% and 15% of total calories. Anywhere in this range is better than the 30% of calories from protein that many people eat today, which is far more than the normal protein requirement.
Early estimates of how much protein a person needs were based on studies of rats. It turns out that rats need up to 11 times as much protein as humans! (Relative to their size, obviously.)
What’s wrong with having more or less than the normal amount? What is protein for anyway?
Protein is used for building and repairing your body, from muscles and blood to hair and nails. It is also needed for the production of hormones, enzymes and anti-bodies. Any left over can be converted to fat and used as a source of energy.
Protein deficiency in children can stunt their growth and prevent normal development.
Adults eating less than their protein requirement will suffer from weakness, low stamina, poor immune function, slow recovery from illness and slow healing of wounds.
These symptoms are seen in third world countries all too often. In the west, people are more likely to eat more than their protein requirements. Too much protein is just as damaging to your health, but symptoms take longer to show up.
Protein, particularly animal protein, is not as easy to digest as fruits and vegetables so too much can cause health problems: “A diet rich in animal proteins leads to diseases such as kidney stones, high fat levels in the blood, high blood pressure and the formation of cancer-inducing agents in the bile.” (Dr Andrew Lockie, The Family Guide To Homeopathy.)
Part of the problem with too much protein in your diet is that protein has an
acidifying effect on your body
, particularly animal protein. Many diseases linked to western living are caused largely by eating too much protein. Think of gout, kidney disorders, arthritis and osteoporosis.
Also, as excess protein is converted to fat, too much can lead to weight gain – another common problem today. See
how to lose belly fat
if you need help with this one.
What are good sources of protein? Should you eat meat?
Some foods are as much a source of arguments as of protein! For instance is it necessary to eat meat? Are milk and cheese good sources of protein? Is Soya a healthy protein food?
Milk and milk products are not necessarily good sources of protein for adults or children. For babies, mother’s milk is the best possible food, but most of us lose the enzymes to digest milk as we grow up. Many people can't digest it properly, and it is one of the commonest food allergens today.
Raw (unpasteurised) milk is easier to digest than pasteurised. Germs are not really a problem - hygienic modern milking methods are a far cry from the days of milking the cow in the muddy field and carrying the milk home in open wooden pails. Unfortunately, governments are convinced of the need to sterilize everything and its almost impossible to buy raw milk.
Soya is another controversial food. It is very high in protein (54% of its calories) and so soya flour is used in many processed foods to increase the protein. It's also fed to livestock to make the animals grow faster or produce more milk. However, soya beans contain several toxic chemicals, which are very damaging to human health. Those who claim that soya is a good food point out that it has been used safely in Asia for thousands of years. This is not strictly true.
What the Chinese and Japanese have been using is small amounts of soy products such as tofu and miso, which have been fermented for up to three years. The fermentation largely destroys the toxins, making it a very different food to modern soy products.
Unfermented soy ‘foods’ interfere with calcium absorption, mess up your hormones and are toxic to your thyroid. The farming industry is aware of this – pregnant and lactating pigs can be fed only very small amounts of soy protein or risk reproductive damage or developmental problems in the piglets (nutritionist Mary Enid, PhD.)
A bigger problem with Soy foods nowadays is that much of it is genetically modified. A 2012
shows that eating GM foods leads to tumours and other life-threatening health problems.
What about meat? Though it's a complete protein, it's best not to have too much meat. Apart from anything else, think of what you’re getting besides the protein. With vegetable foods, as well as protein you get complex carbohydrates and fibre (a good thing). With meat, apart from the protein it’s mostly fat(definitely bad). Also, of course, if it’s not organically reared meat there’ll be agrochemical residues, hormones and antibiotics.
Eggs are a good source of high quality protein but like meat, too rich to eat in large quantities. (The Chinese consider one egg to be enough for six people, for instance in a dish of egg-fried rice.)
Surprisingly, nearly all foods contain some protein, and meat is not the best source. Almost all pulses, nuts, seeds and grains have more than 10% protein. Some of them have more protein than meat. Possibly the best source of protein is quinoa, a grain from South America. It contains high quality protein and is very easy to digest. Vegetables generally have between 10% and 50% protein. So even if you ate only vegetables, you'd probably be getting enough protein.
It is actually very easy to fill your protein requirements. If you eat a varied, wholefood diet, and you are eating enough, you are unlikely to be getting less than your protein requirement.
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