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Από τον Tom Venuto
Are protein supplements really better
than protein foods? Before attempting to answer this question, I should first
preface it by mentioning that I do not sell supplements, nor am I associated
with any supplement company, so you’re getting an honest and unbiased opinion.
Don't get me wrong; I am not anti-supplement by any means. It would simply be
more accurate to say that I am "pro-food." There are a lot of good supplements
on the market, and I've used many of them, including a multi vitamin, creatine
and essential fatty acid (EFA) supplements such as Flaxseed oil. Protein powders
and meal replacements can also be indispensable if you don't have time to eat
every three hours. However, protein supplements are not the master key to your
success, real food is!
Did you ever notice how articles about protein in certain bodybuilding magazines
are seldom objective? Instead, they all seem to be sl****d towards hyping some
"revolutionary" new product. Did you ever wonder why? In my opinion, most
articles on protein supplements are nothing more than thinly disguised
advertisements (some very thinly). Sometimes they give you a very
persuasive-sounding argument, replete with dozens of references from scientific
studies (mostly done on rodents, of course). They even give you an 800 number at
the end of the article to order. (How convenient!)
When protein manufacturers throw around fancy words like cross flow
microfiltration, oligopeptides, ion-exchange, protein efficiency ratio,
biological value, nitrogen retention and glycomacropeptides, it sure sounds
convincing, especially when scores of scientific references are cited. But don't
forget that the supplement industry is big business and most magazines are the
supplement industry. Lyle McDonald, author of "The Ketogenic Diet," hit the nail
on the head when he wrote "Unfortunately, the obsession that bodybuilders have
with protein has made them susceptible to all kinds of marketing hype. Like most
aspects of bodybuilding (and the supplement industry in general), the issue of
protein is driven more by marketing hype than physiological reality and
marketing types know how to push a bodybuilder’s button when it comes to protein
Many nutrition "experts" (read: people who sell supplements), state that there
are distinct advantages of protein supplements (powders and amino acid tablets)
over whole foods. For example, they argue that whey, a by-product of the
cheese-making process, is a higher quality protein than most whole food sources.
There are many different methods of determining protein quality, including
biological value (BV), protein efficiency ratio (PER), Net Protein Utilization (NPU),
chemical score, and protein digestibility corrected amino acid score (PDCAAS).
If you have ever seen advertisements for protein powders and supplements, you
have undoubtedly heard of one or more of these measures of protein quality.
BV is one of the most commonly used and is arguably, the best measure of a
protein's quality. BV is based on how much of the protein consumed is actually
absorbed and utilized by the body. The higher the amount of protein (nitrogen)
that is actually retained, the greater the BV. If a protein has a BV of 100, it
means that all of the protein absorbed has been utilized with none lost. Whole
eggs score the highest of all foods with a BV of 100, while beans have a BV of
Protein quality is certainly an important issue, but it is one that has been
enormously overstated and even distorted for marketing purposes. Whey protein is
truly an excellent protein with a biological value at or near 100. Many
advertisements list whey as having a BV between 104 and 157, but if you look in
any nutrition textbook it will tell you that it is impossible to have a BV over
100. In "Advanced Nutrition and Human Metabolism," BV is defined as "a measure
of nitrogen retained for growth and/or maintenance that is expressed as a
percentage of nitrogen absorbed."
When a protein supplement is listed as having a BV over 100, the company has
intentionally manipulated the number for marketing purposes or unintentionally
confused BV with another method of rating protein quality. Certain whey
proponents claim that whey is "superior to whole egg" so the percentage sign on
BV had to be dropped and the scale extended beyond 100. It was noted by
bodybuilding writer Jerry Branium in IRONMAN magazine that in a study where the
BV of whey was reported to be 157, the author confused BV with chemical score.
Chemical score is a comparison of the amino acid pattern in an ideal reference
protein to a test protein and therefore the number can exceed 100. 157 was
actually the chemical score and not the BV.
Most bodybuilders and strength athletes already consume more than enough protein
(an understatement if there ever was one), so the importance of BV to these
athletes who are already consuming copious amounts of protein has been
overplayed. Even though whey has a higher BV than chicken breast, fish or milk
protein, if the total quantity of protein you consume is sufficient, then it is
not likely that substituting whey for food proteins will result in any
additional muscle growth.
Whether you choose a whole protein food or a protein supplement isn’t as
important as some would like you to believe. For the purposes of developing
muscle, the only guidelines for protein that you must follow are: (1) consume a
source of complete protein with every meal, (2) eat at frequent intervals
approximately three hours apart (about six times per day) and (3) consume a
minimum of .8 grams to 1 gram per pound of body weight. There are times when it
would be beneficial to consume more than one gram per pound of body weight, but
that will have to be the subject of another article.
Because whey protein does have a high BV, it probably offers the most benefits
when you are dieting on very low calories. When your energy intake and
correspondingly, your protein intake, are reduced, whey protein could help you
get greater utilzation of the smaller amount of protein that you are taking in.
In other words, choosing proteins of the highest quality is more of an issue
when you are dieting than when you are focusing on mass gains when total
calories and protein are being consumed in abundant amounts. Whey protein also
provides a way to get high quality protein without the fat, which is also
important when dieting.
It has been suggested that whey may have other advantages besides high protein
quality, although they are frequently overstated. These benefits include
enhanced immunity, increased antioxidant activity and quick absorption. Several
studies in "Clinical and Investigative Science" by Dr. Gerard Bounous of
Montreal have shown that whey protein provides anti carcinogenic properties,
protection from infections, and other enhanced immune responses. Whey protein
was also been shown to raise levels of Glutathione, an important antioxidant
that can offer protection from free radical oxidative damage. While such
findings are very promising, all these studies, which are frequently quoted in
whey protein advertisements, were performed on mice, so it is unclear how well
the results extrapolate to humans.
Another acknowledged benefit of whey protein is its fast absorption rate.
Although there isn’t any evidence that protein supplements digest more
efficiently than whole foods (as is often claimed), they are definitely digested
faster. This is most important after a training session when the rates of
protein synthesis and glycogen re-synthesis are increased. This is the reason it
is often recommended that a liquid meal containing protein and a high glycemic
carbohydrate be consumed immediately post-workout and that whey is the ideal
protein for this purpose. Even in considering post-workout nutrition, there is
still little proof that a liquid protein-carb complex will actually produce
better muscular growth than whole foods, as long as complete whole food protein
foods and complex carbohydrates are consumed immediately after the training
session and every three waking hours for a period of 24 hours thereafter.
Speaking of protein absorption rates, the discussion of fast acting versus slow
acting proteins seems to be the latest hot topic these days in bodybuilding
circles. The interest was sparked by studies in 1997 and 1998 that examined the
differences between the absorption rates of whey versus casein. The researchers
concluded that whey was a fast acting protein and was considered to be more
"anabolic" while casein was slower acting and was considered to be more
"anti-catabolic. " It was further hypothesized that consuming a combination of
these two types of proteins could lead to greater muscle growth. These findings
have prompted the supplement companies to market an entirely new category of
protein supplements; casein and whey mixes. The problem with drawing such
conclusions so quickly is that these studies looked at the speed of whey and
casein absorption in subjects who had fasted for 10 hours before being fed the
protein. Any suppositions drawn from this information are probably irrelevant if
you are eating mixed whole food meals every three hours. Obviously, more
research is needed.
This recent fascination with various rates of protein absorption could be
compared to the interest in the glycemic index. The glycemic index is a scale
that measures the rate at which the body converts various carbohydrate foods
into blood glucose. The higher the glycemic index, the faster the food is
converted to glucose and the larger the insulin response. Therefore it is said
that high glycemic foods should be avoided in favor of low glycemic index foods.
The error in relying solely on the glycemic index as your only criteria for
choosing carbohydrates is that the index is based on consuming a carbohydrate
food by itself in a fasted state.
When carbohydrates are consumed in mixed meals that contain protein and a little
fat, the glycemic index loses some of its significance because the protein and
fat slow the absorption of the carbohydrate. That’s why the glycemic index is
really much ado about nothing and the same could probably be said for the casein
and whey argument. It's just the latest in a long string of new angles that
supplement companies use to promote their protein: free-form vs peptides,
concentrate vs isolate, ion exchange vs microfiltration, soy vs whey, casein and
whey mix vs pure whey and so on. Every year, you can count on some new twist on
the protein story to appear. Certainly there are going to be advances in
nutrition science, but all too often these "new discoveries" amount to nothing
more than marketing hype.
What about amino acid pills? Amino acids pills are simply predigested protein.
Proponents of amino acid supplementation claim that because the amino's are
predigested, the body will absorb them better, leading to greater improvements
in strength and muscle mass. It sounds logical, but this is a gross
underestimation of the body's capacities and actually the reverse is true: The
human digestive system was designed to efficiently process whole foods; it was
not designed to digest pills and powders all day long. Amino's are absorbed more
rapidly in the intestine when they are in the more complex di and tri-peptide
Your body gets better use of the aminos as protein foods are broken down and the
amino's are absorbed at just the right rate for your body's needs. In "Exercise
Physiology; Energy Nutrition and Human Performance," authors Katch and McArdle
state that "Amino acid supplementation in any form has not been shown by
adequate experimental design and methodology to increase muscle mass or
significantly improve muscular strength, power, or endurance."
Furthermore, consuming predigested protein when you are seeking fat loss is not
necessarily advantageous because it shortchanges you of the thermic effects of
real food. Whole foods have a major advantage over protein supplements; they
stimulate the metabolism more. This is known as the "thermic effect of food."
Protein has the highest thermic effect of any food. Including a whole protein
food with every meal can speed up your metabolic rate as much as 30% because of
the energy necessary to digest, process, and absorb it. This means that out of
100 calories of a protein food such as chicken breast, the net amount of
calories left over after processing it is 70. In this respect, the fact that
protein foods digest slower than amino acid tablets is actually an advantage.
A final argument against amino acid supplements is the cost. Amino's are simply
not cost effective. If you don’t believe it, pick up a bottle and do the math
yourself. One popular brand of "free form and peptide bonded amino acids"
contains 150 1000mg. tablets per bottle and costs $19.95. 1000 mg. of amino
acids equals 1 gram of protein, so the entire bottle contains 150 grams of
protein. $19.95 divided by 150 grams is 13.3 cents per gram. Let's compare that
to chicken breast. I can buy chicken breast from my local supermarket for $2.99
a pound. According to Corinne Netzer’s "Complete Book of Food Counts," there are
8.8 grams of protein in each ounce of chicken, so one pound of chicken (16 oz)
has about 140 grams of protein. $2.99 divided by 140 grams equals 2.1 cents per
gram. The amino acids cost more than six times what the chicken breast does! I
don’t know about you, but I’ll stick with the chicken breast.
The biggest advantage of protein supplements is not that they can build more
muscle than chicken or egg whites or any other whole food protein, the biggest
advantage is convenience. It is easier to drink a protein shake than it is to
buy, prepare, cook and eat poultry, fish or egg whites. Consuming small,
frequent meals is the optimal way to eat, regardless of whether your goal is fat
loss or muscle gain. To keep your body constantly in positive nitrogen balance,
you must consume a complete protein every three hours. For many people, eating
this often is nearly impossible. That's when a high quality protein supplement
is the most helpful.
Aside from convenience, the truth about protein supplements is that they offer
few advantages over protein foods. There is no scientific evidence that you
can't meet all of your protein needs for muscle growth through food. As long as
you eat every three hours and you eat a complete protein such as eggs, lean meat
or lowfat dairy products with every meal, it is not necessary to consume any
protein supplements to get outstanding results. Whey protein does have some
interesting and useful properties and supplementing with a couple scoops each
day is not a bad idea, especially if you are on a low calorie diet for fat loss
or when you're using a post workout shake instead of a meal. Aside from that,
focus on real food and don’t believe the hype.
Tom Venuto, CPT, CSCS
Προτεινόμενο άρθρο από τον Tom Venuto:
25 Τρόποι για να αυξήσετε την απώλεια λίπους
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