Protein and Your Body

What is Protein ?

Protein in food is made up of chains of different combinations of twenty amino acids. Eight of these amino acids your body can't live without and can't manufacture (termed indispensable or essential amino acids). Your body needs to be provided with these amino acids from food, and the best way to do this is to eat foods high in protein.

I find it interesting that most of these amino acids actually come from plant sources, which we obtain either by directly eating the plant, or by eating the meat of an animal that has eaten the plant.[1] While this is the case, eating red meat is the best way to get the essential amino acids in our required quantities, as you'd need to eat an awful lot of different plant materials in order to get enough.

What happens to meat, eggs and milk once we eat it ?

Once our bodies actually receive different proteins from milk, eggs and meat, the body breaks the proteins down into their different component amino acids and then uses them as biological building blocks to re-make new amino acids and new proteins for use throughout the body.

When this occurs, the amino acids are transported into the bloodstream using specific carrier molecules. There appears that amino acids compete with each other to be taken into the bloodstream and then transported to areas of the body where the specific amino acids are needed.

In such cases where supplements contain a lot of the same amino acids, the amino acids in excess are taken up, while other essential amino acids may be left behind. [2]

The table below illustrates what you're eating when you're eating meat. Which meats provide the most protein ? Which meats have less saturated fat? Which sources have the most essential fatty acids such as linolenic acid?

Food Source	Processing	Saturated Fat (% DV)	Eight Essential Amino Acids Present	Calcium (% DV)	Linolenic Acid (mg)
100g Chicken Breast	Skinned and Roasted	5%		1%	30
100g Ground Beef	70% Lean Pan Broiled	31%		4%	27
50g Egg	Hardboiled	8%		2%	17.5
100g Crayfish	Cooked W/Moist Heat	1%		5%	22
100g Rabbit	Stewed	5%		2%	140
100g Blue Fin Tuna	Cooked Dry Heat	8%		1%	0
100g Canned Tuna	Canned In Water No Salt and Drained	1%		1%	0
100g Whole Milk	3.25% Milk fat	9%		11%	75

Branched Chain Amino Acids

Food Source	Amount of Protein (g)	Leucine (mg)	Isoleucine (mg)	Valine (mg)
100g Chicken Breast	31	2328	1638	1539
100g of Ground Beef	22.9	1783	1027	1129
50g Egg	6.3	538	343	384
100g Crayfish	17.5	1388	847	822
100g Rabbit	33	2573	1567	1678
100g Blue Fin Tuna	29.9	2431	1378	1541
100g Canned Tuna	25.5	2073	1175	1314
100g Whole Milk	3.2	265	165	192

Looking at the above tables, rabbit is a less commonly eaten meat than chicken or beef, but seems to offer more protein, less saturated fat, a high amount of linolenic acid and has the highest levels per gram of food of protein.

References:

[1] Barasi (1997) Human Nutrition Oxford University Press. Page 60

[2] Barasi (1997) Human Nutrition Oxford University Press. Page 62

Diet & Fitness Tips

If you found this useful, get great diet recipes, fat burning exercises and other articles like this one in our diet & fitness newsletter.

Top Of Protein Page.