Protein
What the heck is protein anyway?
Just as glucose serves as the building block of glycogen, so are amino
acids, which are the building blocks of proteins. Proteins are arguably
the most important component of your cells. They’re involved in
formation of contractile tissue or muscle, they make up a large part
of the structural component of cells, they are a part of enzymes, antibodies,
blood, etc...you name it, protein is part of it. The main function of
protein is to provide the needed amino acids for maintaining an anabolic
(growth) or weight-stable state. However, recent data shows that additional
protein promotes recovery and performance during exercise. (1, 2)
How much protein should you consume?
Suffice it to say that the RDA of 0.8 grams per kilogram body weight
per day is grossly inadequate for anyone whose activity levels exceed
that of a La-Z-Boy recliner. Even though muscle protein degradation
or breakdown increases during exercise, there is a significant increase
in muscle protein synthesis for at least 24 hours after either resistance
or endurance exercise. If you are not getting adequate protein during
this time, then it would make sense that you probably will not gain
lean body mass. I’d suggest 1 gram of protein daily per pound
of body weight. Even if you didn’t pass high school algebra, you
can figure out this one.
How Much Protein Can I Consume at One Sitting?
Great question! Unfortunately, the scientific answer isn’t known.
But I’ll give you the Midwestern common sense answer. Would your
75 year old grandma and the 250 lb, 25 year old mixed martial arts fighter
have the same limitations when it comes to digesting and absorbing protein.
Obviously, the fighter needs more protein to assist with recovery and
repair of muscles. In all fairness, there are studies in which levels
of 30 grams of protein are fed to subjects; and this amount produces
a tremendous rise in blood amino acid levels. I’d imagine that
30 grams of protein per meal is a good starting point. If you eat 30
grams a sitting and you eat 6 times daily, that’s about 180 grams
of protein. For most ‘normal-weight’ individuals, that should
suffice. But imagine if you’re a 300 lb football player or bodybuilder?
You’d either have to eat more protein per sitting or just eat
more meals. The answer to this problem? Consume meal replacement powders
as a protein supplement.
Protein and Bone Health
According to one study, protein intakes do not contribute to the wide
variability in calcium absorption efficiency. (3) Or put another way,
eating protein probably has no effect on bone mineral content. Another
investigation stated verbatim that “several recent epidemiological
studies demonstrate reduced bone density and increased rates of bone
loss in individuals habitually consuming low protein diets.” (3-5)
So one might argue that low protein intakes is the culprit. Either way,
it would be wise to consume both adequate protein and calcium to maintain
lean body mass and reduce body fat.
Adding Protein to Sports Drinks
In a study that compared a traditional sports drink (water, carbs, and
electrolytes) versus a sports drink that contained added protein, they
found that cyclists rode 29% to 40% longer when they consumed the sports
drink with protein than the one without. Also, peak post-exercise plasma
CPK (creatine phosphokinase) levels, an indirect measure of muscle damage,
was 83% lower after consuming the sports drink plus protein. So don’t
believe the baloney about protein dehydrating you (‘cause if it
did, these cyclists would not have performed better) or being unimportant
during exercise. Even a small amount (~3-6 grams) during exercise might
do wonders for you!(1)
References
1. Saunders MJ, Kane MD, Todd MK. Effects of a carbohydrate-protein
beverage on cycling endurance and muscle damage. Med Sci Sports Exerc
2004;36:1233-8.
2. Flakoll PJ, Judy T, Flinn K, Carr C, Flinn S. Postexercise protein
supplementation improves health and muscle soreness during basic military
training in marine recruits. J Appl Physiol 2004;96:951-6.
3. Heaney RP. Dietary protein and phosphorus do not affect calcium absorption.
Am J Clin Nutr 2000;72:758-61.
4. Kerstetter JE, O'Brien KO, Insogna KL. Low protein intake: the impact
on calcium and bone homeostasis in humans. J Nutr 2003;133:855S-861S.
5. Kerstetter JE, O'Brien KO, Insogna KL. Dietary protein, calcium metabolism,
and skeletal homeostasis revisited. Am J Clin Nutr 2003;78:584S-592S.