Animal Protein Sources
* Fish, Poultry
* Milk
* Yogurt
* Cheese
* Eggs
* Supplements (whey, casein)
Plant Protein Sources
* Legumes (beans, peas, lentils)
* Vegetables
* Grains
* Cereals
* Nuts & seeds
However, much like carbohydrate and fat, proteins are not all created equal. Consider the following factors when choosing a protein-rich food or supplement
Protein quality
When choosing a protein, the first factor to consider is quality. Proteins can be divided into two categories, complete and incomplete. Complete proteins contain the appropriate amounts of all essential amino acids (amino acids the body cannot produce). Included in this category are animal/soy proteins. On the other hand, incomplete proteins lack the appropriate amount of one or more essential amino acids. Included in this category are plant proteins (excluding soy).
Generally speaking, complete proteins are of better quality than incomplete proteins. Imagine muscle protein as a large jig-saw puzzle, with amino acids acting as the puzzle pieces. Complete dietary proteins come with all the necessary pieces to finish the puzzle. Incomplete dietary proteins are missing one if not several pieces, making completion of the puzzle difficult but not impossible. The puzzle, containing an incomplete protein, can be finished by combining complementary proteins (proteins that are not deficient in the same amino acids) to form a complete protein. Some complementary protein combinations include:
* grains and legumes (ex. rice and beans)
* grains and dairy (ex. oatmeal and milk)
* nuts/seeds and legumes (ex. hummus-chick peas and sesame seeds)
Fat content
The next factor to consider when choosing protein-rich foods is the fat content. Lean proteins will promote a lean muscular body while fatty proteins will promote a soft flabby body. You make the decision! Some helpful hints for picking lean proteins include:
* Grilled over fried
* Skinless over skin
* White meat over dark meat
* Low-fat dairy over full-fat dairy
* Egg whites over whole eggs
* Remove any excess visible fat from meat
* Avoid plant proteins prepared with heavy cream, butter or oil
Rate of absorption
Most protein supplements are made from either whey protein, casein protein, or a mixture of the two. The major difference between these two milk proteins is the rate of absorption. Whey protein is rapidly absorbed helping to induce muscle-protein synthesis following a training session. On the other hand, casein protein is slowly absorbed providing a long steady flow of amino acids, helping to prevent muscle-protein degradation. Post-training supplements containing a mixture of both fast and slow proteins are superior to their individual counterparts because they not only induce muscle-protein synthesis but they also help to prevent muscle-protein degradation. So spice up your diet and diversify your proteins, keeping the aforementioned factors in mind!
