Figures for food are averages for several foods in each
category4 and were taken from the bible of
nutrient data, the USDA
Food
and Nutrient Database. Human need from studies1,
WHO2, and US govt. recommendations.3
The
2006 ISSN paper on protein & strength
by Michael Bluejay
Original: April 2010 • Updated March 2012
In 2006 the International Society of Sports Nutrition
published this
lengthy
review, summarizing a plethora of studies on the
effects of protein in strength training. It's
somewhat useful as a one-stop-shopping source for the results of
many studies done, but there are some important caveats:
It's not the final word. The research didn't
stop in 2006. This review paper doesn't contain the
definitive last word about protein in strength training.
It has to be read carefully. For example, in
some places the paper refers to more muscle being built at
"higher protein levels", but the crucial question is, "Higher
than what?" The answer is generally "higher than
the low-protein group in the study," but you have to figure
that out yourself. That's because the studies in
question generally have a group consuming less than
the official recommendations — meaning that the subjects in
the poorer-performing group were eating less protein than the
average supplied by vegetables. (The paper didn't
explain how this was possible, and I haven't read all of the
particular studies to see if they explain it, though the ones
I looked at did not.)
Some of it is flat-out wrong. For example, the
review paper incorrectly states "vegetable based products
typically lack one or more EAAs [essential amino acids]",
which is absolutely false, easily disprovable by consulting
any nutrient database.
Perhaps most significantly, the paper's authors misquote
the studies they're summarizing, on more than one occasion.
Let's look at some examples.
About one study, the review paper says, "These results indicate
that a diet with the majority of its protein from meat products is
more effective for supporting the goals of a resistance training
program then a vegetarian diet." But if you look at the
actual study, you see that the omnivores in the study did not
get a majority of their protein from meat. In fact, the
actual study's abstract opens with "Very limited data suggest that
meat consumption [not a majority] by older people...."
[emphasis added] Besides the misquote, the other
qualifications are also absent from the paper. The paper
also omits crucial bits from the study in question, such as that
"Maximal strength of the upper- and lower-body muscle groups that
were exercised during RT increased by 10-38% (P < 0.001), independent
of diet."
That is, there was no difference in strength gains between the
meat-eaters and the vegetarians. Finally, supposedly both
groups ate the same amount of protein, which I find very hard to
believe. Meat certainly contains more protein than plant
foods, so I believe there's something we're not being told about
the subjects' diets. Unfortunately the
study doesn't detail exactly what the participants ate.
Vegan
bodybuildersshatter the
myth that vegans are skinny and malnourished.
About another study, the review paper says, that muscle gains
in a milk-consuming group were "significantly greater"
than another group, but the study actually says that the
difference was "not statistically different". The actual
study also says that "strength gains were not different
between the soy and milk-suplemented groups." The review
paper didn't bother to mention that crucial fact. (The
study did say sat the milk-consuming group produced more muscle
fiber (even if not to a statistically significant degree), but
they don't report how much extra muscle each group built.)
Now let's talk about whey. Some of the studies
reviewed are the source of the fascination with whey as a
miracle muscle-builder. But every whey-related study in
the review compared a group consuming added whey to a group
consuming nothing extra! This is like having a
race with only one person, and declaring that person to be the
fastest. So these studies are hardly an endorsement of
whey over soy-, rice-, or pea-based supplements, since those
supplements weren't studied. The closest they came was the
study involving milk (not whey) vs. soy mentioned above, which
found that "strength gains were not different between the soy
and milk-supplemented groups" and that changes in muscle fiber
between the groups was "not statistically significant".
Remember earlier when I said that the paper has to be read
carefully? Here's another good example: One of
the studies reviewed is the source of the advice you hear at the
gym to "eat some protein within two hours of training".
What you didn't know before now was just how small the amount of
protein studied was: ten grams.
There's nearly that much in a single large potato.
There's ten grams in a measly one and a half Odwalla
chocolate peanut bars. And just two
cups of oatmeal has 12 grams. This goes to what I
say in the main article: If
you eat food, you're eating protein.
From this many will conclude that ten grams is the optimal
minimum amount of protein to eat after exercising, which is also
wrong. The control group didn't eat any protein for
two hours after exercise. So the groups ate either ten
grams or nothing. So we can't conclude that ten
grams is our minimum, it could be less. We don't know,
because lesser amounts weren't studied. (Personally, I
think ten grams is actually likely in the ballpark for the
optimum amount, we just can't draw that conclusion from the
study. And again, a piddling ten grams is super-easy to
get from just about any food anyway.)
Another thing to look for when reading reviews of studies is how
much was the difference between the groups? If a
summary somewhere says something like "meat-eaters had more muscle
mass increase than vegetarians" that's the kind of thing that
veggie-critics would trumpet to the ends of the earth about the
supposed inadequacy of vegetarian diets. But if you looked
at the numbers and found that the meat-eaters improved by 75%
while the vegetarians improved by 65%, then suddenly vegetarianism
doesn't look quite so inadequate after all. It also has to
be put into context: Is it so wonderful to build muscle
slightly faster if it means you're way more likely to die
early of heart disease, cancer, or stroke? As vegan bodybuilder Charlie
Abel
said, "I personally know of a weight lifter in his sixties
that had both hips replaced. I actually saw one famous bodybuilder
who was featured in the documentary Pumping Iron, who is getting
around on crutches these days."
