How much protein do you really need?

Sunday, March 8, 2009

Protein can be a tricky subject when it comes to how much an average person needs on a daily basis. Because the amount you need can vary based on factors such as your age, gender and level of physical activity. But what doesn’t vary is that we all NEED protein. It is indispensable for the growth and maintenance of every single cell in our body.

Okay, I don't want to get too scientific – but this one scientific fact is the important one, germaine to this discussion. We need 20 different amino acids in order to produce all of the proteins in our bodies. We can manufacture 10 of the amino acids with, thankfully, very little effort on our part. The other 10, however, either cannot be made or cannot be made in quantities large enough to be of any use. And this, my friend, is where protein in your diet comes into play. Those missing 10 essential amino acids must be obtained from food.

Okay, so back to the original question. How much do you need? To find the definitive answer to this question, I turned to our government and climbed up to the meat and beans level of its food pyramid. Here is a small part of their helpful chart:

Women

19-30 years old - 5 ½ ounce equivalents
31-50 years old - 5 ounce equivalents
51+ years old - 5 ounce equivalents

Men

19-30 years old - 6 ½ ounce equivalents
31-50 years old - 6 ounce equivalents
51+ years old - 5 ½ ounce equivalents

These amounts are appropriate for individuals who get less than 30 minutes per day of moderate physical activity, beyond normal daily activities. Those who are more physically active may be able to consume more while staying within calorie needs. (Side note: Isn’t it interesting that they default to people who get LESS than 30 minutes of exercise per day?)

The glaringly obvious problem with this chart is that no one has ANY IDEA what an “ounce equivalent” is. Of course, leave it to the U.S. government not to give you any of these figures in grams. Let’s talk “ounce equivalents” instead. Wouldn’t want to go all metric on a government website.

In general, 1 ounce of meat, poultry or fish, ¼ cup cooked dry beans, 1 egg, 1 tablespoon of peanut butter, or ½ ounce of nuts or seeds can be considered a 1-ounce equivalent from the meat and beans group.

So now they’ve forced me to do the math. If a sirloin steak has about 8 grams of protein per ounce, then that means a woman aged 31-50 who exercises less than 30 minutes per day, needs roughly 40 grams of protein on a daily basis. Although, theoretically, based on the whole “ounce equivalent” thing, I could just eat 5 tablespoons of peanut butter every day and be done with it.

Sometimes I think the old standard of .4 grams of protein per pound of body weight is still a good rule of thumb. For example, if you weigh 130 pounds, using this formula will tell you that you should get about 52 grams of protein per day – not all that far off from the government recommendation – and you don’t have to deal with ounce equivalents.

Of course, anyone working out regularly will need more. And that’s a whole different post. But one important point to remember is that the human body can only assimilate 50 grams of protein in one sitting. Anything in excess of that will just get flushed right out of your system.

Although animal products are the most common source of protein, it’s really not a good idea to put all of your eggs in that basket, so to speak, because they tend to be a lot higher in cholesterol and saturated fats than vegetable sources like beans, soy and nuts. And don’t forget the actual vegetables themselves - broccoli and spinach, for example, which are low-fat, cholesterol-free protein options.

Darn it. Too long again. Sorry. Condensed version: Eat protein.

Footnote for the scientifically inclined: These 10 “essential” amino acids which must be obtained from food are: threonine, lysine, methionine, arginine, valine, phenylalanine, leucine, tryptophan, isoleucine and histidine. The 10 we CAN make are glycine, alanine, serine, cysteine, aspartic acid, glutamic acid, asparagine, glutamine, tyrosine and proline.

13 comments:

Anne said...

Thanks for this! I'm a lacto-vegetarian, so making sure I'm getting enough protein is a big concern of mine. I'm always trying to figure out how much I'm getting and how much I need. :)

Rhea said...

Protein is SO important to our bodies. I agree!

Camevil said...

Protein is always one of those factors that I can never have a firm handle on. So, I just err on the side of excess. Plus, the extra protein is more satisfying to the tummy.

On the other hand, I cannot imagine eating 50 grams in one sitting. That's like steak topped with chicken on a bed of hummus.

Mrs. Jelly Belly said...

I know - 50 grams in one sitting seems like so much - but an 8 ounce sirloin steak is 64!

Pam said...

Visiting via SITS! Who knew there was so much to know about protein. I've got a lot to learn.

kristisummer said...

I am a big advocate of protein. Great for helping to build lean muscle mass and so much more. My new obsession is greek yogurt. Most greek yogurts contain at least 15-20 grams of protein per serving, and it keeps me full all morning.

Mrs. D Lightful said...

I definitely need to work on getting all my protein in...I am such a carb girl. :)

Mrs. Jelly Belly said...

Kristi - I had no idea Greek yogurt had that much protein. I hear people saying all the time, "oh Greek yogurt is so great" but they never said why. Now I know why. I'm picking some up today - thanks!

Tanya said...

I probably eat more protein than my body requires. This is so informative Jean!

Fruitfulvine2 said...

Good post. I especially like the reference to the fact that vegetables actually have protein which most people seem to be unaware of. Thanks.

Nana said...

Some more great info! Thanks.

Cindy DG said...

Protein is so important, especially for vegetarians! Great post!
Cindy
http://vegetarianmamma.blogspot.com

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