Proteins

What are Proteins?

Proteins are macromolecules that are made up of amino acids chains.  When we eat proteins, we break them down and reuse the amino acids for other functions.  Proteins provide energy, tissue repair and growth, strengthen our immune systems (by creating antibodies which help destroy viruses and bacteria), and create enzymes.  Proteins are also play a role in your body's production of hemoglobin, which carries oxygen throughout the body.  They provide four calories per gram.

There are two types of amino acids: essential and nonessential.  Essential amino acids cannot be created by the body, so we need to obtain these through our diets.  There are nine essential amino acids.  Complete proteins are protein sources that contain all of the essential amino acids.  Some examples of complete proteins include animal based sources such as fish, meat, and eggs.  Incomplete proteins are sources that lack a couple of essential amino acids.  Two incomplete proteins that (together) provide adequate amounts of proteins are called complementary proteins.  Some examples of incomplete proteins include rice, beans, and tofu.  Non essential amino acids can be put together by the body; therefore, we do not need to obtain these from our diets.


What Proteins Should I Eat?

There are many different healthy sources of proteins.  You do not have to focus on consuming only complete proteins.  You can consume incomplete proteins that together contain all essential amino acids that you need.  10-35% of our diet should consist of proteins.  Some sources of proteins include:

• Poultry: lean meats (beef), eggs, fish (salmon), turkey, chicken, tuna
• Dairy: milk, cheese, yogurt
• Vegetables: kidney beans, lentils, black beans, pinto beans, soybeans, cauliflower, and peas 
• Nuts, seeds, and grains

Eating the right proteins can reduce the risk of heart disease, lower your cholesterol and blood pressure, aid in muscle mass (rebuild muscles quicker), and help you lose weight.


Protein Deficiency

If your body is not receiving enough protein, you may develop the following symptoms:

• Weak immune system
• Slow growth
• Muscle atrophy
• Fatigue and weakness
• Weight Loss

References:

http://www.sciencelearn.org.nz/Contexts/Food-Function-and-Structure/Science-Ideas-and-Concepts/Macronutrients

http://www.fitday.com/fitness-articles/nutrition/vitamins-minerals/the-3-primary-macronutrients-and-their-importance.html#b

http://www.cdc.gov/nutrition/everyone/basics/protein.html

http://helpguide.org/life/healthy_eating_diet.htm

www.mckinley.illinois.edu/handouts/macronutrients.htm

http://web.up.ac.za/sitefiles/file/46/4134/856/Macronutrients.pdf

http://kidshealth.org/kid/nutrition/food/protein.html#

http://www.whfoods.com/genpage.php?tname=nutrient&dbid=92

http://www.webmd.com/fitness-exercise/guide/good-protein-sources

http://healthyeating.sfgate.com/benefits-eating-lean-proteins-6083.html


Pictures:

http://dougkelsey.com/wp-content/uploads/2011/02/iStock_000011313073XSmall.jpg
https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcRk4fJDX6v6X56xCUYMrAF_Ip95pNY31Lvr4w9L09aX6AQvAH94FA