This blog has been churning in my head for a while, but walking in to work this morning and having one of my co-workers read a list of "Top 10 Lean Proteins"as written by a REGISTERED DIETICIAN and posted on foxnews.com (http://www.foxnews.com/health/2011/04/26/10-lean-proteins/) really pushed me over the edge. (Thanks Matt!) Her list is as follows: quinoa, skyr (Icelandic style yogurt), egg whites, nut butters, oatmeal, soy, black beans, white meat chicken, daily catch (fish), sunflower seeds. WHAAAAAAATTTTTTT?????????? C'mon, you're kidding, right? I wish it was a joke, but it wasn't. Right there on the Fox News website for all to read..so it MUST be true...sigh, here we go again.
What is protein, why do we need it? Protein comes from the greek word proteios meaning: of the first or prime importance. Protein is basically a chain of amino acids. Different proteins are made up of different amino acids in different combinations. There are 20 different amino acids, 9 of which are considered essential (must be obtained through the diet) with another 6 considered conditionally essential (must be obtained through diet during stressful conditions- such as exercise). The remaining amino acids are considered non essential as the body can produce them from other compounds. Proteins are needed to produce anitbodies for the immune system, enzymes for different reactions, are components of structural tissues (muscle tissue, collagen, elastin), transport molecules (hemoglobin) and some hormones (insulin, thyroid hormone and growth hormone). Protein can also be oxidized (broken down) for use as fuel.
Our bodies have zero storage capacity for protein, therefore our requirements must be met each and every day. Protein requirements for individuals has been a highly controversial topic for as long as I can remember (and probably was long before I was born as well). Some RDs (as well as some doctors) will claim .4 grams of protein per kilogram of bodyweight (g/kg) is sufficient, while other RDs and sports nutritionists (myself included) stand by 1 gram of protein per pound of bodyweight (g/lb). Either way you go, you MUST consume your protein every day. If protein requirements are not met each day, muscle tissue will be metabolized to fulfill amino acid requirements. This slows tissue repair, decreases strength (and muscle size), and impairs performance. All around a bad situation.
Ok so what's the big deal where it comes from? Well, as I said earlier proteins are made up of chains of amino acids in different combinations. Proteins that contain all 9 essential amino acids are considered complete proteins as they provide tissues with the aminos necessary for growth. Examples are: milk, eggs, meat, fish, poultry- animal sources. Proteins that are lacking even ONE of the essential amino acids are considered incomplete and are not capable of causing growth. In fact, a diet comprised of incomplete proteins can lead to protein malnutrition. No, I am NOT making this up. Incomplete proteins include plant sources such as corn, lentils, beans, and nuts.
Did you hear me? Yes, I just said plant sources...and yes 2 of the things I specifically listed were on Tanya Zuckerbrot's list of "Top 10 Lean Proteins".
That's right folks, not all protein is created equal. Just like clothes, cars, electronics and just about anything else you can think of. Some are just plain better than others. That is how the world works people, accept it and move on.
So why do some people say that nuts or nut butters (or whatever) is a 'source of protein'? Well, my guess is that because it actually contains some amino acids so when you look at the nutrition facts (the numbers on the back of the package) there is a number next to protein. It does not say zero, therefore it is a source of protein. That is a great plan *cough, cough*. That is like a builder telling you that your new house will be constructed out of particle board. I know, you are probably laughing thinking 'what the heck?'. Really though, if we are playing by the same rules as this 'source of protein' game particle board is a source of wood. It has wood in it, right? So what's the big deal? The big deal is: A) what is the quality of the wood? And B) what percent of the particle board is comprised of wood?
Your answer- A) haaa, chips and dust and shavings B) hmmm.
Let's do the same thing for nuts..specifically peanut butter. Ok, we already know it is an incomplete protein so quality is not great at all. Now for the amount of that protein in peanut butter. To figure this out, let's look at the nutrition info for peanut butter. You can look at any kind you'd like they are all going to be about the same. Looking at Smucker's Natural Chunky Peanut Butter you see that one serving (2TBSP) is 200 calories, 16 grams fat, 6 grams carbohydrate, 7 grams protein. Let's do the math here - 16grams of fat x 9 calories/gram of fat gives us 144 calories from fat. Six grams of carbohydrate x 4 calories/gram gives us 24 calories from carbohydrate. Seven grams of protein x 4 calories/gram gives us 28 calories from protein. What percent of the total calories is that? Hmmmm 72% for fat, 12% for carbohydrate, 14% for protein. Now, I am definitely NOT a math major nor am I a statistician, but I would have to say that peanut butter is a great source of....wait for it...FAT, not protein. Well, unless you think that particle board is a good source of wood. (If it IS a source of protein, then one would have to say that it is also a source of carbohydrate as the numbers are almost the same for the two)
What about beans? I love beans. Especially black beans. Ms. Zuckerbrot states: "Black beans have 8.5 grams of protein and 7.5 grams of fiber per half cup. Enough said." Well, yes they actually do. They also have 21 grams of carbohydrates --which, if we did the math- would qualify them as majority carbohydrate source...NOT protein. Oh wait, beans are also an INCOMPLETE source of protein. ENOUGH SAID.
What about combining incomplete protein sources to 'make' a complete protein? Sure, go ahead..if you would like to increase you caloric consumption as well...let's try it. We'll go with the ever popular beans and rice. We'll use black beans and brown rice. One cup of brown rice has 5 grams of protein and we know that a half cup of black beans has 8.5 grams. Together that makes 13.5 grams of protein. Hmmm, but also gives us 67 grams of carbohydrates and totals about 340 calories. Hmmmmm. Just for kicks and giggles let's look at chicken. First of all we know it is an animal source so it is by default a complete protein. Two ounces of cooked chicken breast has MORE protein than the rice and beans mixture (2oz chicken has 18 grams), and has 99 calories!!!!!! Ninety-nine calories, 2 grams of fat, zero grams of carbohydrate and 18 grams of protein. Hmm, what does THAT work out to as far as percent composition? Seventy two calories from protein and 18 from fat..soooo about 73% protein, 0% carbohydrate and 18% fat. PROTEIN SOURCE!!!! In general, I am not going to consider something a source of ________ (insert whatever you'd like) unless it has over 70% of that thing in it. I am NOT going to consider something that has a trace amount of something a SOURCE of that something and certainly not a GOOD source of it. Most especially when there are sooooo many sources that are much much better.
Wait, it gets better. According to a study done by Young and Pellett (Am J Clin Nutr 1994;59)
"Contrary to popular belief, there is no known maximum amount of protein that can be absorbed in one meal. However, in general it is known that humans typically absorb approximately 95% of ingested animal proteins and approximately 85% of ingested plant proteins."Did you hear that? So of the 13.5 grams of protein from your beans and rice you probably only absorbed 11.4 grams. The 18 grams of protein from the chicken left you with 17.1 grams. So you would need to consume EVEN MORE of your beans and rice. Whew, I'm full just thinking about it.
Let's recap this. You need protein every day. You need complete proteins. Complete proteins are animal sources. Plants are NOT animals. Plants are NOT complete proteins. Beans are NOT protein. Peanut butter is NOT protein. You're welcome.