Selecting The Best Protein Sources For Faster Muscle Gains

By Xavier Fox

Recently BodyFitness featured an article on whey protein and its many benefits. That article mentioned that whey protein has the highest biological value of all protein sources, making it a superior choice for maximum absorption and effectiveness. However, we are by no means implying that other sources of protein are not also excellent choices for helping us recover from tough workouts and putting on some more muscle. So let’s take some time to discuss the subject of protein, and how we can select sources that will maximize our gains.

As our loyal BodyFitness readers already know, protein is what your body uses to rebuild muscle tissue that is broken down during resistance training. If you workout and do not consume enough protein to rebuild the muscles you have broken down, then your muscles will actually get smaller and weaker, because your system will break down existing muscle tissue in order to create amino acids that are used in the recovery process. Protein does a lot more than just rebuild muscle tissue; it also helps our immune system function properly; aids in the production of enzymes, which are our body’s catalyst for ALL of its chemical reactions; helps control blood sugar levels; and enables us to produce many of our hormones. Proteins make up 75% of our body’s tissues.
Once it is ingested your system breaks protein down into its elements. These elements are commonly known as amino acids. There are two categories of amino acids: essential and non-essential. Essential amino acids are ones that must be consumed or supplemented, because our body cannot manufacture them from other sources. Now, just because an amino acid is classified as a non-essential amino acid, it does not mean that you do not require it. It simply means that your system can manufacture these amino acids from other amino acids, so you do not have to consume them directly as long as you consume abundant supplies of other amino acids that can be converted. There are nine essential amino acids: histamine, isoleucine, leucine, lysine, methionine, phenylalanine, tryptophan, valine, and threonine; and there are twelve non-essential amino acids: alanine, arginine, aspartic acid, cysteine, cystine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine.
The reason we needed to mention amino acids is that the combination and ratios of amino acids in a specific protein determines its biological value. In an article recently published in BodyFitness, a concept known as the glycemic index was discussed in an article about carbohydrates. Biological value is used to grade a source of a protein much as glycemic index is used to grade a source of carbohydrates. Proteins can be found in both plant and animal food sources, which differ in their amino acid composition and digestibility. Animal protein tends to be of a higher nutritional quality, but the correct combination of plant proteins can also provide a quality source of protein. Plant sources must be used in specific combinations in order to yield the correct combination of amino acids for assimilation. Animal proteins are said to be “complete”, since the body can use them as they are, whereas plant proteins must be combined with each other in order to get the necessary combination of amino acids that allow the body to use them. The more complete a protein is, the more digestible it will be, and thus the higher the biological value will be.
It is not only comparable to the glycemic index of carbohydrates, but it is much the same as bioavailability when discussing supplements. Bioavailability is the rate at which a substance is absorbed in our system and the percentage of it that is absorbed and used at its point of action. The bioavailability of a substance is measured by the subject’s blood plasma concentration after a single dose of a supplement in a specified amount of time. This concentration measurement is compared to the concentration after the same amount of time that an intravenous injection of the same supplement (and dosage) had. This is because intravenous injections have the best bioavailability, so they are given the score of “1” and all comparisons of different forms are given a percentage score (e.g. 0.80 = 80% as effective as the intravenous form). If you ingest an identical amount of grams of a supplement in two different forms, there is a good chance that one form will provide you with a higher usable dosage than the other. When a product is produced in a way that the bioavailability is higher, you can take less of it to get the same effect as you would with a supplement that had a lower bioavailability. Biological values of proteins are very similar in concept: the higher the biological value of the protein, the more efficiently your body uses it.
Just like glycemic index and bioavailability, the best biological value protein source is scored with a perfect 100 on the biological value scale, and other sources are compared to that and scored accordingly. With glycemic index, glucose is the quickest absorbing sugar so it is scored as 100, and all other carbohydrates are scored according to the rate they are absorbed compared to glucose. As you read above, intravenous injections are scored a 100 in supplements, and other forms of supplements are scored as to how quickly they hit the system as compared to injections. With protein, whole egg is the naturally occurring source that has the best biological value, so it is used as a reference and specified a score of 100, and all other sources are compared to it. Notice that we said the best “naturally occurring” source. There are sources that have a higher biological value than egg, but they are all manufactured sources.
Although a source of protein may have a certain score attached to it, the number associated with the score is not an indicator of the precise percentage that is absorbed. For example, one gram of protein will contain four calories in all cases. Let us go back to our example of egg, since they are our benchmark protein source. Our body actually uses only about 94% of the protein in egg even though it has a score of 100; the score of 100 simply means that it is the best. So if you eat one gram of egg protein, although you ingest four calories, you only utilize 0.94 grams of protein. The score is simply to let you know how well the protein source rates as compared to others. For example, a score of 90 means that particular source is 90% as effective as the standard (whole egg).
If the biological value does not give you the entire story, then why is biological value important? Well, it gives you insight to what percentage and how quickly the protein will be absorbed and used by your body. If protein source number one has an extremely low biological value, and protein source number two has an extremely high biological value, there is a good chance that you will have to eat a whole lot more of source number one in order to get the same usable amount of protein as source number two. That can be very valuable information if you plan on staying lean. If you need to eat 1,000 calories of one food to assimilate the same amount of protein as 300 calories worth of another, as well as consume three times as much fat, wouldn’t you want to stick with the 300-calorie choice? Would you rather drink a small glass of whey protein isolate that contains very little calories, no fat, and no sugar, or eat an entire plate full of beans and rice that contains much more calories and fat, and can even cause your blood sugar levels to rise quickly since white rice is high on the glycemic chart?
Complete proteins have high biological values since they contain adequate amounts of the essential amino acids. Proteins of high biological value are found in many animal sources such as milk, eggs, cheese, meat, poultry and fish. Plant sources are normally lacking specific essential amino acids and have lower biological scores. In addition, compared to animal sources, relatively large amount of plant products (high total calories) must be consumed to get enough protein. The exception in plant products is the soya bean, which contains relatively large amounts of high biological value protein.
Now, for all you vegetarians out there, as stated earlier, meats are a much more complete source of protein than vegetables (plants). Plant protein must be consumed in certain combinations in order to be useful. Meat protein can stand alone; vegetable proteins can be divided into three categories: legumes, grains, nuts and seeds. These categories can be combined in a couple of different ways to promote proper amino acid combinations that will make the proteins absorbed useful. Legumes and grains should be combined, or you can combine nuts and seeds with legumes or grains.
Legumes are plants whose seeds grow in pods such as peas, beans and peanuts. When the pods of legumes are in their early stages, they are especially high in vitamin A and iron. As they ripen, their protein value increases significantly. Grains include plant sources such as rice, wheat, and corn. The very amino acids that are missing in beans are found in abundance in grains. The same is true for other legumes, so it important to combine them with grains if you do not wish to include meat sources in your diet. Soya beans are a great choice and contain almost twice as much protein as other types of beans.
Nuts and seeds not only give you nutrition, they provide flavour and a good texture to meals to make them more enjoyable. Nuts tend to be a little higher in fat than seeds, and they sometimes have as much fat as protein. However, they contain mostly unsaturated fats and are a good source of essential fats. Nuts and seeds do contain a lot of protein, but they must be combined with legumes or grains in order for your system to use them as a complete protein. Pumpkin and squash seeds are the seeds with the highest protein, while sunflower seeds are next. Sesame seeds and flax seeds also provide high amounts of protein, and they are great sources of calcium. As for nuts, walnuts, almonds and cashews are the best choice for protein; many other types have more fat than protein.
As you can see from the chart below, your best choices for protein are not animal sources, but the scientifically developed whey protein sources. However, it is important that you eat many different sources of protein, because many of them contain specific vitamins, minerals and other nutrients. Most vegetable sources rate barely above 50, but if consumed in the combinations described above those ratings will increase dramatically.
Notice that beef is on the list. Be careful when choosing your cuts of beef, because you may end up consuming a lot more fat than you intended. Most cuts of beef are graded by flavour. Well, beef gets its flavour and texture from the fats that are in it. So if you are in the store, you may think that the higher grades of meat that are more expensive such as porterhouse and filet steak must be better for you because of the cost and higher grade. However, they are the cuts with the most fat. The lower grades of beef have much less fat, and therefore will be a little tougher and not as flavoursome, but they will be better for your waistline, heart, and arteries.
Be smart when choosing your protein sources, and try to consume the highest quality proteins that you can. This way, you will be sure to make the most efficient use out of the calories you consume as well as save money. Of course, life would get pretty boring if you ate whey protein isolate several times a day, so try to get a good variety of sources. Variety will not just keep you from getting bored; it will allow you to get a variety of nutrients other than protein that the many sources have to offer.

Protein Source	Biological Value
whey protein isolate	159
whey protein concentrate	104
eggs (whole)	100
egg whites	88
chicken/turkey	79
casein	77
soy	74
fish	70
lean beef	69
cow’s milk	60
brown rice	57
white rice	56
peas	55
whole wheat	49
soy beans	47
whole-grain wheat	44
peanuts	43
dry beans	34