Some folks might argue that 1 gram per pound of body weight a day is excessive. Smart folks might have picked up on the fact that some experts call for 1 gram of protein per kilogram of body weight, not per pound. Others might note that still other experts call for 1 gram per pound of lean body mass, not per pound of whole body weight. Finally, I might actually be criticized for advocating too little protein. Some serious atheletes take more than I'm recommending. So why the 1 gram per pound per day?
First is the issue of protein quality. Nutritionists measure protein quality in terms of biological value (BV). BV is basically your body's ability to digest and use the protein you eat and it varies greatly by source. Here's the second link I found through Google:
|Source||Protein (g)||Biological Value (BV)|
|Chicken breast 2.8 oz (79 g)||26||79|
|Tuna 3.0 oz (85 g)||24||83|
|Egg (1 whole)||6||100|
|Milk (1%, 1 cup)||8||91|
|Lean beef 2.5 oz (72 g)||22||80|
|Lentils (1 cup)||16||50|
|Red Kidney Beans (1 cup)||15||50|
|Bread (1 slice) 25 g||2||54|
|Rice (1 cup)||4||59|
|Pasta (1 cup)||4||54|
|Oatmeal (1 cup)||13||55|
As you can see, different protein sources provide different BV values, showing that not all protein sources are created equal. The protein you get from animal sources tends to be much more useful for your body as compared to plant sources. This has profound implications for your diet, especially if you're vegetarian or vegan.
Notice right away that eggs are the gold standard of whole foods in terms of BV. One egg might only have 6 grams of protein but it is highly potent. Still, in bang-for-your-buck terms, tuna, chicken breast, and lean beef give you more grams of protein per serving and still have high BV values.
So if we're wanting to meet our protein requirements for the day, we would need to eat a lot less of beef, tuna, etc. in terms of volume to get our protein. Vegetarians and vegans will have to consume much more bulk and the quality of the protein is much less. That means they would have to consume that much more to make up for the deficit in quality as well as quantity. I'm not saying it can't be done, especially by lacto-ovo vegetarians. But it makes the diet that much harder in terms of protein requirements.
The problem that BV shows is that not all the protein you consume is the same quality, yet this gets overlooked in absolute values. When people think they're getting 150 grams of protein a day at 150lbs. of body weight, the fact that not all of that protein is equally bio-available doesn't usually enter into the equation. Looking at the chart above, one cup of lentil beans has 15 grams of protein but your body can only absorb half of it because the BV of lentil beans is only 50% So in real terms, you're only getting 7.5 grams of protein from a one cup serving. What happens when you eat 150 grams of protein but your body can't use a certain percentage of it because it isn't digestable enough?
If not all of that protein is equally bio-available then it stands to reason that erring on the side of more rather than little will ensure that a client gets enough quality protein. You might eat 150 grams of protein a day at a body weight of 150lbs. and actually absorb 120 grams because of the varying BV of the different foods you ate that day. For all practical purposes, you just consumed 120 grams for all the good it did you. If so, you'd be deficient for that day. See how this works? Even at the supposedly high rate of 1 gram of protein per pound of body weight, you're still not likely absorbing and using that exact amount. Now what happens when you don't even consume 1 gram per pound a day?
Bascially you run around in a protein deficient state all the time.
The seond major reason I recommend so much protein is that it's as close to a magic bullet in terms of nutrition as we're ever likely to see. Consider that the two most requested fitness goals are fat loss and muscle gain. Despite the disparities in the requirements to meet those two goals, one recommendation unites them: high protein intake.
Starting with the obvious, protein is necessary to support muscle growth in those wishing to gain weight. The body must have the basic building blocks it needs for protein synthesis, otherwise mass can not physcially be built. If you're only consuming what your body needs for maintanence, you can't add mass. You need extra for that in terms of calories and protein.
Ironically, protein also meets the needs of dieters by both supporting the growth of lean muscle tissue and providing excellent satiety -- your feeling full and staisfied from a meal. Increased lean muscle tissue protects your body from injuries as you get fit, allowing you to work out longer and harder and stay injury free. Increased lean tissue also allows you to use heavier weights as you exercise -- greatly increasing your calorie expenditure. you'll burn a heck of a lot more calories swinging a 20kg kettlebell than an 8kg kettlebell.
Satiety is often over-looked but protein is very satisfying when consumed at high quantities and qualities. A big salad before a big steak is a very satisfying meal and eating this way regularly can help you avoid the excess calories you'd get from over-consuming carbohydrates.
Another over-looked factor in protein consumption is that it takes more energy to digest protein than the other macronutrients fat and carbohydrates.
Here's how it works:
"A protein-based meal will elicit a thermic effect that is close to 30 percent of the total calories itself," explains Jack Groppel, Ph.D., co-founder of LGE Performance Systems in Orlando. This means that if you have a protein-based meal of 600 calories, you'll burn 180 calories just by eating it. This is largely due to digestive processes as well as the extra energy the liver requires to assimilate and synthesize the amino acids in protein.
So you burn 25-30% of the calories from protein just by digesting it. Now see why I recommend high protein intake for fat loss clients? Imagine eating 600 calories for the price of 420. That's what higher protein intake can do for you. You can consume a higher calorie, more satisfying diet that supports your training and keeps you more injury free through higher protein intake. That's a major reason I say this is as close to a magic bullet in nutrition as we're likely to get.
Finally, I know that even if I suggest a higher protein intake, most people will still fall short of it, at least on some nutritionally poor days. Few of us can 100% control what we eat every single day. What would happen if I suggested a lower protein intake? Clients would definitely be protein deficient. Keep the protein intake high constantly and those days where you fall short will not set back your training recovery or leave you open for injury. Set the protein bar too low even on good nutrition days and you will pay a heavy price on poor nutrition days. With a low protein recommendation, you're on the boderline all the time and eventually it will catch up to you -- either in terms of an injury or by reaching a training plateau that you won't be able to overcome.
We often forget there's a major difference between having an abundance of health and fitness and always doing the bare minimum. With the bare minimum of protein, exercise, or anything else, you're never far from losing what little you've managed to gain in the first place. Your body is the same way. If you want great results, you have to give it in abundance what it needs to attain super health and fitness. That includes protein.
Give it the bare minimum and you'll achieve the bare minimum in return.