Protein: What Do You Need To Know!

Nargis Akhter MBBS, MS, RDN, LDN, CLT

Updated May 9, 2021

Carbohydrates, fats & proteins are the macronutrients essential for growth. It is important to understand about how they function

"Amino acids are the building blocks of protein".

When we eat protein rich food (chicken, beef etc) the body breaks them down into amino acids which are then used by the body for various functions in the body.

Functions of Proteins:

1. Growth & Maintenance

a. For increase muscle mass & growth

b. Pregnancy

c. Lactation

d. Illness/injury

e. Structural protein (hair, nails, collagen)

2. Hormones

3. Enzymes

4. Neurotransmitters

5. Defense (immunity)

6. Transport (nutrients)

7. Blood clotting

8. Wound healing

9. Boost metabolism

10. Antibodies

11. Contractile (muscle contraction)

There are different types of amino acids:

  1. Essential amino acids - Body cannot make them, must be given from outside

  2. Non-essential amino acids - Body can make these from other amino acids

  3. Conditionally essential amino acids - They become essential under some stressful conditions.

  4. Sulfur containing amino acids -

  5. Branched Chain Amino Acids -

  6. Aromatic Amino acids -

Essential amino acids are essential for the growth and our body cannot make it so they must be provided from the diet.











• Tryptophan is an essential amino acid needed for general growth and development, producing niacin, and creating serotonin in the body. Serotonin is thought to produce healthy sleep and a stable mood which is why tryptophan in turkey is sometimes attributed to making people sleepy.

High tryptophan foods include:

· Nuts

· Seeds

· tofu

· cheese

· red meat

· chicken, turkey, fish,

· oats, beans, lentils, and eggs.

The recommended daily intake for tryptophan is 4mg per kilogram of body weight or 1.8mg per pound. A person weighing 70kg (~154 pounds) should consume around 280mg of tryptophan per day

Sources of Phenylalanine


Cottage cheese

Wheat germ

Phenylalanine is converted to tyrosine, tyrosine crosses the blood brain barrier (BBB) there it is converted to catecholamine (dopamine, epinephrine, norepinephrine). Decarboxylation of tyrosine results in the formation of tyramine. Tyramine is found in fermented, aged, pickled food. Aged cheeses and sauerkraut.

Uses of tyrosine

1. L-dopa used in Parkinson’s is made of tyrosine

2. Depression

3. In stress

Non-essential Amino Acids can be made from the other aa that are present in our body:

Alanine - from pyruvic acid

Arginine - from glutamic acid

Asparagine - from aspartic acid

Aspartic Acid - from oxaloacetic acid

Glutamic Acid - from oxoglutaric acid

Glutamine - from glutamic acid

Glycine - from serine and threonine

Proline - from glutamic acid

Serine - from glucose

Tyrosine - from phenylalanine

Conditionally essential amino acids When the body experiences periods of extreme trauma or stress from thermal injury, sepsis, surgery, or wounds, nonessential amino acids become conditionally essential, or conditionally indispensable.







Sulfur containing Amino Acids are methionine & cysteine. Methionine is an essential aa, and cysteine is a non-essential aa.These amino acids are present in hair, skin, & nails.

Sources of methionine & cysteine:

1. Animal based sources of methionine are; beef, turkey, chicken & egg

2. Plant based sources of methionine; nuts, seeds, grains, lentils, legumes, chickpeas,

3. Cruciferous vegetables; broccoli, cauliflower, arugula, kale, radish. These vegetables are rich in sulfur, however too much of these can also cause diarrhea, IBD (Inflammatory bowel disease).

Branched Chain Amino Acids -BCAA

Branched Chain Amino Acids are leucine, isoleucine and valine. These are essential amino acids, must be taken from the diet. These BCAAs are broken down in the muscle not in the liver, that is why these are commonly used for muscle building when combined with proper exercise.

Aromatic Amino Acid

1. Phenylalanine

2. Tyrosine

3. Tryptophan

RDA- Recommended Dietary Allowance:

An average, healthy person needs to consume 0.8grams to 1.0grams/kilograms.

(0.8g -1.0g) x (weight in kg)

This requirement changes at different times, for e.g during pregnancy, lactation, illness, injury, healing.

Almost 80% of our bodies are made up of protein. We need protein in every stage of our lives; infancy, childhood, adolescent, pregnancy, lactation, old age, injury, illness.

It is important to choose the right type of protein, taken at the right time. Best time to consume is after exercise.

Protein also boost our metabolism, gives a feeling of satiety. 10% -35% of our daily calories must come from protein.

Hope this information will help you make better choices. This is just a general reading. Do seek professional advice for your very specific needs.

Do let me know if you have any question in the comment section below!

8 views0 comments

Recent Posts

See All