The Role of Proteins in our Diet

Proteins are the building blocks of life. Actually, the word protein is derived from the Greek word proteios, meaning “primary”, “in the lead”, or “standing in front”. Proteins are so important for our overall health and well-being, that we should think of including them first in setting up our meals and overall diet.  Proteins are what we are made of at 45%. That’s what we need. Besides some fat and essential fatty acids; the rest of our diet is fuel for energy.

In fact one of the most drastic weight-loss diet protocol, used on morbidly obese individuals, is called a Protein Sparing Modified Fast (PSMF). The patient must consume enough protein, which depends on lean mass, quality essential fatty acids, along with multi-vitamin and multi-mineral supplements. (Please do not do this. It’s not a healthy and/or efficient way to lose weight for most people).

What are proteins?

Proteins are made up of amino acids. Think of amino acids as the bricks in a brick wall. Of the 22 standard amino acids, 9 are called essential amino acids. They are considered essential, because it’s indispensable that our diet provides them in sufficient quantity. Protein sources are also qualified according to how many of the essential amino acids they provide:

A complete protein source is one that provides all of the essential amino acids. Animal-based foods; such as, meat, poultry, fish, eggs, and cheese are considered complete protein sources.

An incomplete protein source is one that is low in one or more of the essential amino acids. Complementary proteins are two or more incomplete protein sources that will provide adequate amounts of all the essential amino acids when they are combined. This is very important for vegetarians. Sources of incomplete proteins are vegetable-based foods; grains, nuts, beans, and seeds.

Proteins have many important functions in the human body, without them we would be unable to repair, regulate, or protect ourselves:

  • Building and repair of body tissues, including muscles
  • Enzymes, hormones, and many immune molecules are proteins
  • Processes such as water balancing, nutrient transport, and muscle contractions need protein.
  • Our hair, nails, skin, collagen, cartilage, and eyes are made of protein
  • Most neurotransmitters are made from amino acids
  • Amino acids are the building blocks of our brain’s network.
  • Amino acids can stimulate or calm our brain as well as nourish it.

What makes us feel satiated? The other benefit of protein.

Some foods can more easily contribute to the feeling of satiety than others. The calorie-counting tables do not reflect this, so studies examining the effects of foods on hunger can be interesting.

Highest satiating power was found in foods with high levels of protein and fiber content. What is means is that if hunger is an issue for us, a breakfast of composed of a vegetable omelet with a bit of cheese would sustain us better until lunch, than a bowls of cereal with skim milk and some fruits of equal calories.

So how much protein should we get in our diet each day?

There in no lack of opinions on this topic on the internet and numbers are all over the places.

My short answer is: it depends. It depends on you sex, age, height, lean mass, health condition, level of activity, if you are in calorie balance or not, if you take anabolic substances, etc. We should never calculate our protein needs as a percentage of our diet. Our body needs a set number of grams of protein per day and it will not vary greatly even if we modify our activity level. Our fuel intake, fat and carbohydrate, will.

Let’s start with the “sufficient” U.S. Recommended Dietary Allowances (RDA) per age groups.

Recommended Dietary Allowance for Protein

  Grams of protein/day

Children ages 1 – 3


Children ages 4 – 8


Children ages 9 – 13


Girls ages 14 – 18


Boys ages 14 – 18


Women ages 19 – 70+


Men ages 19 – 70+


Sufficient does not mean optimal and vibrant health for most people. Actually the RDA was developed during World War II by a committee established by the U.S. National Academy of Sciences to investigate issues of nutrition that might “affect national defense”. The allowances were meant to provide nutrition for civilians and military personnel. Because of food rationing during the war, the food guidelines took food availability into account.

The easy peasy way to know if your intake is sufficient, is to make sure you eat at least a palm-of-your-hand-size portion of cooked animal protein three times a day.

For those who want something more precise, I suggest this easy calculation as a starting point:

  1. Height in centimeters.  Ex:  5’8 = 173 cm
  2. Subtract 100.  Ex:  173-100 = 73
  3. 73 rounded to 75 grams +/- 10 grams = (65-85), should be a daily target for a 5ft 8in or 173 cm woman. If you are a 5ft 8in or 173 cm man, add 10 grams to the calculated range (75-95).
  4. Never go under the RDA recommended amount for your age group.

If you are dieting, are lifting weights, are sick or are recovering from an injury, aim for at least the top of the range.

If you are recovering from an addiction or are recovering from an eating disorder, aim for a minimum or 90 grams of protein per day, independently of your height.

One ounce of lean-ish cooked meat, poultry or fish, contains roughly 7 grams of protein. An egg contain 7 grams. Greek yogurt, cottage cheese, mozzarella and  protein powder are a great sources too, look on the label of your particular brand for their protein content.

If you find you have trouble digesting proteins, you could look into Hydrochloric Acid supplementation.

Hope it help!