Proteins low in one or more of the essential amino acids are considered
incomplete proteins. Plant, or commonly called vegetable proteins, are
examples of incomplete proteins because most are low in one of the essential
amino acids. For example, grains tend to be short of lysine. The amino acid
that is in shortest supply in a given protein is called the limiting amino
acid. The limiting amino acid tends to be different in different proteins.
This means when two different foods are combined, the amino acids in one
protein can compensate for the one lacking in the other. This is known as
protein complementing. Vegetarians and vegans need to combine plant proteins
(incomplete proteins) to get all the essential amino acids found in complete
proteins.
There are three major categories of vegetable proteins:
- Legumes - plants whose seeds grow in pods such as peas, beans, and
peanuts
- Grains - rice, wheat, corn and others
- Nuts and Seeds - walnuts, almonds, cashews, sunflower seeds, pumpkin seeds, squash seeds, flaxseeds
Like animal proteins, some vegetable proteins are better than others. Here
is a general "fact list" concerning vegetable proteins:
- Nuts are generally
lower in protein and higher in fat than seeds.
- All nuts and seeds are high in fat, but these are mostly unsaturated.
- Nuts and seeds have an excellent quality protein.
- Pumpkin or squash seeds are the highest in protein of all commonly eaten
seeds.
- Sunflower seeds are second highest in protein.
- Flaxseeds and sesame seeds are high in protein and a good source of calcium.
- Walnuts, almonds and cashews are the highest in protein of the commonly
eaten nuts.
- Brazil nuts, pecans, filberts, and hazelnuts are higher in fat and have less
protein proportionately.
- Coconut is lower in protein and higher in saturated fat than most other
nuts.
- Beans (legumes) provide many nutrients including protein,
low glycemic
carbohydrates, vitamins, iron and calcium. They also contain soluble fiber,
have no saturated fat and help stabilize blood sugar. The best beans for
protein are soybeans (contain over twice as much protein as other beans),
lentils, garbanzo and black beans.
There are four major principles of
combining vegetable proteins to get all the essential amino acids found in
complete proteins. Those principles are:
- Combine legumes with grains
- Combine nuts or seeds with legumes or grains
- Combine animal products with any vegetable product
- Add a small amount of meat to a meal of vegetables
Recommended Daily Allowance (RDA)
Before we discuss the recommended daily allowance of protein, we need a
basic understanding of protein synthesis. Protein synthesis is a process
where the digestive system breaks down the protein we consume into their
basic amino acids. Our cells rebuild them again, in a different order, to
form the particular type of proteins they need. Chemicals left over after
protein synthesis are converted to glucose and used for energy. Due to the
body's demand for protein, it is essential to include enough in our daily
diet. Otherwise we start digesting the proteins in our muscle tissues (you
lose muscle mass).
It's important that you get enough protein in your diet to avoid having your
body turn to your muscle for protein. So how much protein does a guy need
then? According to the US National Academy of Sciences, healthy people need
about 0.8 grams of high quality protein, per kilogram of bodyweight - that's
just under 0.4 grams for every pound. Most people get more than the RDA in
their daily diets.
However, many experts say the RDA is too low for those who exercise on a
regular basis and for those who want to increase muscle mass. Dr. Peter
Lemon, a top researcher on this subject, wrote in a recent review paper
that, "...the RDA for those engaged in regular endurance exercise should be
about 1.2-1.4 grams of protein per kilogram of body mass (150%-175% of the
current RDA) and 1.7-1.8 grams of protein per kilogram of body mass
(212%-225% of the current RDA) for strength exercisers." In addition, the
current recommendation by the majority of bodybuilders, writers, coaches and
others is one gram of protein per pound of bodyweight for athletes who want
to increase muscle mass.
To calculate your weight in kilograms,
divide your body weight in pounds by 2.2
I’m not a serious bodybuilder and I’m not trying to gain tons of muscle
mass so to me, one gram of protein per kilogram of body mass seems to be
more than I need (or am comfortable with taking). I strength train four
times a week and aerobic exercise three times a week. What seems to work
well for me is about 1.5-1.6 grams of protein per kilogram of bodyweight,
which for me is about 123 - 131 grams of protein per day. You will want to
monitor and tweak your own protein intake to find an amount that works best
for you and your fitness goals.
Click here to read Part 1:
Complete Proteins