For the longest time, protein was an afterthought, and
carbohydrates and fat got all of the attention with respect to human
health. However, advances in research have found that consuming
adequate amounts of protein, especially that of high quality, can
promote optimal wellness and vitality. Recent popularity of diets
including Atkins and South Beach has propelled protein into the
forefront. While there are a significant number of flaws in these
dietary programs, they do serve one important purpose: getting
people thinking about protein.
Types of Protein
Protein is found in a vast array of foods. However, certain foods
contain protein that is considered to be of a superior quality. For
example, the protein found in a chicken breast is of higher quality
than the protein found in pasta. Protein quality is measured by how
it promotes net protein balance within the human body and is a
function of the amount of essential amino acids (cannot be produced
by the body) that it contains. For omnivores, the top protein
sources would be items such as chicken, fish, red meat, eggs and
dairy. As for non animal eaters (e.g., vegans), top quality protein
could come from soy (especially fermented soy) and hemp. What is
important is that one’s diet consists of a variety of high quality
protein sources throughout the day.
Protein and Health
Nutritional recommendations define the primary use of amino acids
as substrates for synthesis of body proteins. However, there is
emerging evidence that additional metabolic roles for some amino
acids require plasma and intracellular levels above minimum needs
for protein synthesis.
Enzymes, hormones, skeletal muscle, bones and hair - these
are just a sample of substances that contain protein. Thus, to
function properly, we need to eat some protein. For example, it was
once believed that excess protein could be detrimental to bone
health by creating an acid environment that would leach calcium from
the bones. While it is true that for some people the excess intake
of proteins (especially from animal sources) can take a toll on
skeletal strength, it is also true the consumption of adequate
protein in the diet is essential to bone strength and thus, reduces
the risk of osteoporosis.
Some of the most interesting research regarding protein is its
impact on body weight. Protein’s ability to increase satiety and
therefore decrease caloric intake is one mechanism behind this
outcome. Therefore, if you were to eat the equivalent in calories of
chicken versus white pasta, you will likely be hitting the fridge
sooner after the bowl of pasta. High-fat junk food (especially if it
is low in fibre) may be the least filling of them all.
Another way protein may help with the battle of the bulge is in
its ability to increase thermogenesis (calorie burning) in
comparison to carbohydrates and fat. New research shows that
carbohydrates, fat and protein all act differently in our bodies,
proving that calorie counting is more complicated than simple
addition. Protein has a higher thermic effect of feeding (TEF) than
the two other macronutrients and therefore uses up more calories
during digestion. One particular amino acid, leucine, has been
found to turn up the body’s heat. Interestingly, one of the best
dietary sources of leucine comes from a properly processed whey
protein supplement. While the TEF of protein is about twice that of
carbs or fat, the overall contribution of TEF to total calories
expended is likely to be somewhat small.
Keep in mind that one of the main reasons why high-protein,
low-carbohydrate diets result in rapid weight loss is due simply to
the large reduction in calories. Take away the pasta from the pasta
with meat sauce, and you are sure to create a calorie imbalance.
How Much Protein Do We Need?
The standard recommendation for protein intake for the average
person is 0.8 grams of protein per kilogram per day. However, this
recommendation is impractical considering that the vast majority of
people in well fed societies consume well over this amount. For
example, this level is only 64 grams of protein for an 80 kilogram
person. It is also not nearly enough for anyone who exercises
regularly. Basically, only a truly sedentary person could get away
with such a small amount. Peter Lemon has for a number of years been
at the forefront of protein research when it comes to exercise, and
through various studies, he has determined the following:
- Individuals engaging in regular endurance type exercise should
aim for about 1.2-1.5 grams of protein per kilogram of body weight
- Individuals engaging in regular resistance training should aim
for about 1.4-1.8 grams of protein per kilogram of body weight.
- Those involved in both types of exercise on a regular basis
(e.g., hockey and basketball players) will likely need the most
total protein. However, if an athlete is consuming well over 2,000
calories per day, there should be no problem getting enough total
protein even without any supplementation. A bigger concern is
making sure they are getting enough high-quality protein and not
making up calories with nutritionally devoid food.
One also needs to keep in mind the fact that different people
have different metabolic needs. Some of us (like this author) seem
to function particularly well on a high-carbohydrate diet while
others do better living like the cavemen. Therefore, simply saying
that there are set protein guidelines would be much too
presumptuous. See Noah Hittner’s Q&A titled “Metabolic Typing” for more information about Metabolic
Typing and diet.
Dangers of Protein
While the concerns over high protein intake have been blown
somewhat out of proportion over the years, there are a few
precautions that need to be taken.
- Individuals with kidney problems will most definitely need to
moderate their protein intake as by-products of protein
degradation are filtered through the kidneys.
- Kidney stones seem to be increasing at alarming rates. Some
health experts believe that as more people follow high-protein
diets, this trend is likely to continue. However, recent research
shows that a beer gut is just as important as a risk factor.
- Perhaps the most worrisome issue surrounding protein intake is
the diminishing quality of protein from animals. Factory farms,
environmental pollution and medication use has seriously cast
doubt over the safety of regularly consuming animal proteins. In
addition, high protein diets are a serious stressor for Mother
Nature. Factory farming is one of the true horrors of modern
society. It is strongly recommended that protein rich foods such
as chicken and beef come from natural sources and from farmers who
do not pump their animals full of hormones and antibiotics. In
addition, animals that graze on open pasture have a better
When to Consume Protein
Consuming protein prior to exercise (especially resistance
exercise) appears to result in an improved net protein balance,
which can bring about greater gains in muscle mass and strength than
with just training alone. The amount of protein needed for this
effect appears to be small – maybe no more than the amount in an
For a long time, it was assumed that only the consumption of
carbohydrates during exercise would bring about improved exercise
performance. However, recent research is showing more promise for
the combination of carbohydrate and protein as a way to improve time
to exhaustion. The reasons for this benefit are still in question,
but increased insulin concentration and thus uptake of nutrients is
believed to be one mechanism.
There has been some indication that consuming protein immediately
following exercise is crucial for recovery and gains from training.
The research is getting closer to proving that this practice is
indeed very important. However, there is some indication that
calories either from carbohydrates, proteins or a combination of
both is just as if not more important for exercise recovery. What
needs to be proven is whether protein consumption 30 minutes after a
workout would be significantly better than protein intake an hour or
more after a workout and exactly how much protein is needed with
respect to long-term lean body mass growth and strength.
Physiologically, it makes sense that consuming protein as close to a
workout as possible would bring about better results, but the hard
data still needs to be fine-tuned. Despite this, it is still prudent
to recommend the consumption of high quality proteins such as whey,
chicken and eggs soon after an exercise session to promote training
results and reduce muscle soreness, especially if it involved
Data indicates that proteins that provide the largest amount of
essential amino acids are better for promoting anabolism. In
particular, the branch chain amino acid leucine seems to work
synergistically with insulin to stimulate protein synthesis.
Carbohydrate consumption alone following exercise has also shown to
produce a more favorable anabolic environment.
It is interesting to note that the addition of protein to a
carbohydrate solution following exercise has shown to increase
glycogen (carbohydrate stores) recovery after exercise more than
just carbohydrates (except when large amounts of carbohydrate are
consumed for several hours). It is assumed that higher insulin
levels are responsible for this outcome.
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with and without creatine monohydrate combined with resistance
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- Flakoll, P.J. et al. Postexercise protein supplementation
improves health and muscle soreness during basic military training
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- Lemon, P.W. et al. Beyond the zone: protein needs of active
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