What Is The Protein?

The word ‘protein’ refers to a type of molecule in food that can be broken down into amino acids.

The body needs twenty amino acids – as a biological machine it can create (or synthesize) eleven of these itself.  However there are nine, called ‘essential amino acids’ that the body cannot create and has to gain through the consumption of food.

These ‘essential amino acids’ are: Tryptophan, Threonine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Valine and Histidine.

When we eat, the body breaks down the protein in food in order to create the amino acids that it needs.

Although most foods contain protein some foods are richer in some of the essential amino acids than others. Usually, therefore, foods need to be combined so that the body receives all the amino acids it needs on a daily basis – part of the reason that a varied, balanced diet is essential to us.

What Protein Does In Human Body?

Protein is the body’s building block. All of our organs, including the skin, are built from proteins, as are the muscles, hair and nails.

Many hormones are proteins, and, the immune system, digestive system and blood all rely on proteins to work correctly.

Protein is therefore an essential part of our diet, vital to development and correct functioning of the body.  Protein is particularly important for children and adolescents – as they grow and develop into adults proteins are used to produce tissue.  Protein is also particularly important for pregnant women.

If our diets contained no protein then our bodies would start to break down muscles in order to produce the protein it needs – our bodies are good at storing fats and some sugars but not good at storing proteins.  It is therefore necessary to continually replace the protein that our bodies use.

Proteins need fuel in order to work – like a car needs fuel. Fuel is provided from the carbohydrates and fats in our diet. The production of amino acids in the body is also reliant on other nutrients especially vitamins B and zinc.

What is Good Source of Protein?

Protein is a macronutrient necessary for the proper growth and function of the human body. A deficiency in protein leads to muscle atrophy and impaired functioning of the human body in general.

Foods highest in protein per calorie include fish, cheese, turkey, chicken, lean beef, pork, tofu, yogurt, milk, beans, lentils, eggs, nuts, and seeds. Below is a list of foods with the highest protein to calorie ratio, for more information, see the sections on protein dense foods, other protein rich foods, low calorie high protein snacks, and protein isolates.

1. Fish (Cod, Tuna, Salmon) – 17g (35% DV) in 3 oz (85g)

1 gram protein per 4.2 calories
20g (41% DV) in 100g

Other fish high in protein per fillet(3oz or 85g): Tuna (22g), Salmon (22g), Halibut (22g), Snapper (22g), Perch(21g), Flounder and Sole (21g), Cod (20g), Tilapia (17g).


2. Cheese (Non-Fat Mozzarella) – 36g (71% DV) in 1 cup, shredded (113g)

1 gram protein per 4.4 calories*
32g (63% DV) in 100g.

Other cheese high in protein per ounce(28g): Parmesan (10g), Romano (9g), Low-fat Swiss Cheese (8g), Low-fat Cheddar (6g), Low-fat Cottage Cheese (5g). *Low Fat Mozzarella and Cottage Cheese provide the most protein per calorie, full fat cheeses typically only provide 1g protein per 20 calories and are less optimal sources of protein.



3. Lean Turkey and Chicken (Turkey Breast) – 25g (50% DV) in 3 oz (85g)

1 gram protein per 4.5 calories
30g (59% DV) in 100g

More Chicken and Turkey: Chicken Leg – Drumsticks (60g) provides 16g protein. Chicken Thigh (37g) provides 9g protein. 3oz serving of Chicken Breast (85grams) provides 14g protein.




4. Lean Beef and Veal (Low Fat) – 31g (61% DV) in 3 oz (85g),1 gram protein per 5.3 calories
36g (72% DV) in 100g

T-Bone Steak 3oz (28g) provides 19g of protein, 1 Piece of Beef Jerky (20g) provides 7g of protein.






5-Tofu – 6g (13% DV) in 1 slice (84g)

1 gram protein per 7.9 calories
7g (15% DV) in 100g

1 cup (252g) of firm tofu provides 20g protein. 1 cup of soft tofu (248g) provides 16g protein. 1 cup of tempeh (166g) provides 31g protein.


6-Yogurt, Milk, and Soymilk – 14g (27% DV) in 1 cup (8 fl oz) (245g)

1 gram protein per 9.3 calories
6g (11% DV) in 100g

1 cup skim milk (245g) provides 8g protein, 1 cup soymilk (243g) provides 8g protein.





7-Eggs (Especially Egg Whites) – 6g (13% DV) in 1 large (50g)

1 gram protein per 11.9 calories
13g (25% DV) in 100g

1 Egg White (33g) provides 4g protein, 1g protein to 4.4 calories. 1 cup of scrambled eggs (220g) provides 22g protein.
Click to see complete nutrition facts.




How much protein do you need?

The Recommended Daily Allowance (RDA) for protein is 52 grams for adult men, 46 grams for adult women, and 71 grams for pregnant and lactating women. Your own protein needs may vary by your level of activity and muscle mass. Refer to the chart below for specific RDAs by age and gender.

Graph of protein Recommended Daily Allowances for different demographics

Low Calorie Snacks High in Protein (50~200 Calories Each)

  • Canned Tuna
    42 grams protein in 1 can (165g / 6oz)
    191 calories
    1g per 4.6cal
  • Dry Roasted Soybeans
    17grams protein in 1/4 Cup (43g)
    194 calories
    1g per 11.4cal
  • 3 Pieces of Cheese (Parmesan)
    11 grams protein in 3 cubic inches (30g)
    117 calories
    1g per 10.6cal
  • Dry Roasted Peanuts
    9 grams protein in 1/4 Cup (37g)
    214 calories
    1g per 23.8cal
  • Almonds
    8 grams in 1/4 Cup (36g)
    206 calories
    1g per 25.8cal
  • Non-Fat (Skim) Milk
    8 grams in 1 cup (245g / 8oz)
    83 calories
    1g per 10.4cal
  • Pistachios
    7 grams in 1/4 Cup (31g)
    176 calories
    1g per 25.1cal
  • Sunflower Seeds
    7 grams in 1/4 Cup (35g)
    205 calories
    1g per 29.3cal
  • Soymilk (Unsweetened)
    7 grams in 1 cup (243g / 8oz)
    80 calories
    1g per 11.4cal
  • Hard Boiled Egg
    6 grams in 1 egg (50g)
    78 calories
    1g per 13cal
  • Toasted Whole Wheat with Yeast Extract Spread (Marmite)
    6 grams protein from 1 slice bread and 1 tsp marmite (48g)
    137 calories
    1g per 22.8cal