Monday, November 7, 2011

Our Body’s Protein Requirements

Protein is required in our diets for growth and tissue repair/replacement. If we do not consume enough protein our body will take the protein it needs from the cells in our bodies (catabolism). This is why bodybuilders consume so much protein - to make sure their bodies always have sufficient protein available to build grow, repair, and replace muscles (anabolism).

It makes sense to think that the more active a person is, the more protein they require. Activity, especially hard exercise, causes tiny tears in your muscles that are later repaired (using protein). This is what makes you bigger, faster and stronger.

So, how much is enough protein? If you are a body builder you might be eating mostly protein in an effort to build as much muscle as possible. And it works - body builders are big consumers of protein.

But, how much is enough for those of us mere mortals who work out a bit but are mostly just average Janes and Joes?

WebMd reports that the Institute of Medicine recommends we get at least 10 percent, and no more than 35 percent of our calories from protein. Reference

And the National Academy of Sciences also recommended a range of 10 to 35 percent. Reference

Another source, The China Study, quotes 12% as the minimum protein required for growth in animals.

OK - that was fun, now let’s put all that in perspective. Let’s say you weigh 170 pounds, and are moderately active. You probably need somewhere around 2500 calories per day. And, if 10 percent of your calories come from lean chicken, you would need to eat a skinless chicken breast a day to give you the roughly 250 calories you need from protein. That’s roughly a half pound, 8 ounces, of lean meat per day. From which you get roughly 60 grams of protein. As a reference, a typical American meat-eater consumes about 93 grams of protein daily—more than anyone else in the world on the average. Reference

If you are not so active, and only weigh 120 pounds, likely a half a chicken breast would be about right.

Or, if you are a body builder, weigh 250 pounds, and work out a lot, you may well need 3 chicken breasts per day to meet your minimum protein requirements if you are not eating any other protein (as in beans, nuts, tofu...).

There is also a lot of discussion in the body-building world about “High-Quality” protein. The belief is that the body will have an easier time making more muscle if the food we take in is very similar to muscle. Makes sense, huh? So, that half pound of chicken breast sounds like a good deal all the way around.

While it might not be obvious so far, this posting is about risk - or, more to the point, it is laying some ground work for talking about the risk associated with eating animal-based protein. But, before getting into that subject, I wanted to see if I could lay out some numbers for our consideration as I delve into the issue of risk tomorrow.

Give some thought, based on the above examples, how many chicken breasts you should be eating each day.


  1. Cool website! How can I find your RSS feed?

  2. I will have to ask my lovely wife what a RSS feed is and where one can find it.