Protein, Oh Protein, What are You Good for, Oh Protein?

I hear so much hype about protein and how amazing it is.  It seems that while carbs and fats are being discriminated against, protein is being given the Nobel Prize.  Maybe that's a bit overboard, but you get the point.  True, protein is amazing, but not always for the reasons we might think.

I briefly touched on protein in What's in the food I eat? There I explained a little bit about the building blocks of protein, amino acids. It's important to understand that it is really amino acids that your body needs.  These amino acids build body tissues, enzymes, hormones, neurotransmitters, antibodies, and much more. If you do not have ALL of the amino acids you need, some of these things will not be built, and your health could suffer in various ways. This isn't really a problem most of the time in our society because we eat so much meat, but it can be something that vegetarians and vegans struggle with if they are not careful.

The best source of whole protein is meat.

Because I know you are all SOOO very interested, here's a brief breakdown on the functions of protein in your body:

• Building of body tissues such as muscle and connective tissue.
• Blood proteins (albumin and globulin, if you're curious) maintain fluid balance between the blood and the surrounding tissues through osmotic pressure. This helps keep enough fluid in your blood while ensuring that the surrounding cells get enough nutrients.
• Acting as buffers, protein keeps the pH of your blood in a healthy range (7.4 to be exact). If the pH changes too much, you will likely die. 
• Forming enzymes, hormones, and neurotransmitters (for more detail on what each of these are, visit the glossary page of this blog). 
• Proteins act as flags on the outside of a cell to tell if it is your cell or a foreign cell (kind of like a jersey is used to tell which team you are on).  Other proteins in your blood can recognize when a cell is not on their team, and send other team members to attack it.  This is called and immune reaction.  You are all probably aware that you have an immune system that protects you from getting sick.  Proteins play a huge part in that system.
• Transporting nutrients from one part of the body to the other.
• Protein can be used to make glucose (the sugar your brain eats) when you don't eat any carbs for a time. However, this has some negative side effects and should not occur for a long period of time.
• Protein can also provide energy if needed, but most of your energy should come from carbs and fat.  You need protein for more important things.

So how can I tell how much protein I need in my diet?  It's simple enough that almost anyone can figure it out.  The Recommended Dietary Allowance (RDA) for protein is .8 grams per kg of body weight per day. Since we are more used to weighing ourselves in pounds, I'll translate.  There are 2.2 lbs in 1 kg, so you can simply divide your weight in lbs by 2.2 to get your weight in kg.  The average female needs about 46g/day and the average male needs about 56g/day.

I challenge you to take a look at how many grams of protein you eat a day.  More than likely, it is above this amount.  If so, should you be worried?  No, not necessarily.  There is no harm in eating a bit more protein than the RDA recommendation.

A note to all those who eat very high protein diets because they believe that it will help them to build muscle faster.  Research has proven that serious athletes do not need to each much more protein than the RDA in order to build muscle.  The best advice for athletes is to get closer to 35% of calories from protein (the higher end of the AMDR). Most of the extra protein athletes often eat is just excreted in their urine (they pee it out) anyways.  I just thought I would share that info before you spend a ton of money on protein shakes.  If you really feel like it helps you, go for it, it's not going to hurt you.  You're just going to have really expensive pee  :)

So there you have it, the rundown on protein.  Don't you really want a hamburger now? I do :)

-Kamie

Facts from Wardlaw's Perspectives in Nutrition, 8th Edition (a college textbook) and Dietary protein for athletes: from requirements to metabolic advantage from Applied physiology, nutrition, and metabolism [1715-5312] Phillips yr:2006 vol:31 iss:6 pg:647 -654.