Choosing the right proteins

Protein Classification: Complete and Incomplete

• Complete proteins like soy and animal sources, are defined as complete because they contain all nine essential amino acids (EAA), 

• Incomplete proteins found in most vegetables and grains, and they are incomplete because they lack one or more EAAs. 

Value of protein or ranking in terms of its strength as a protein depends on amino acid content and digestibility or something known as the Protein Digestibility Corrected Amino Acid Score (PDCAAS). The highest PDCAAS for a food is 1.0, meaning that after digestion, it provides at least 100% of the recommended amount of essential amino acids per unit of protein

Animal Protein:  Contain all nine EAAs, animal proteins are complete proteins, are also abundant in essential nutrients like B12, calcium, zinc and iron.

• An ounce of beef or chicken provides 7-10 grams of protein

Vegetable Proteins: need to be combined to create a perfect score. Eating a variety vegetables and then combining them with legumes listed below allows one to get a complete complement of EAA's. 

Seeds: All seeds are incomplete proteins. Flax, sesame and sunflower seeds provide 2-5 grams of protein per ounce. Ditto with trendy hemp and chia seeds. Potent pumpkin seeds triumph with about 9 grams per ounce. Seeds are good sources of healthy fats, vitamin E and essential minerals like magnesium, copper and zinc (USDA 2013).

Nuts: Almonds, walnuts and cashews provide 6-8 grams of incomplete protein per ounce. Packed with healthy fats, fiber, vitamin E and minerals, nuts are an integral part of the Mediterranean Diet (Guasch-Ferre et al. 2013). Nut-rich diets can lower cholesterol (Damasceno et al. 2011); the FDA allows the claim, “Scientific evidence suggests, but does not prove, that eating 1.5 ounces per day of most nuts (e.g.: almonds, hazelnuts, peanuts, pecans, some pine nuts, pistachio nuts and walnuts) as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease” (FDA 2013).

Legumes: Alfalfa, clover, peas, beans, lentils, carob, soy and peanuts are well-known legumes. Of these, soy contains the most protein with about 43 grams per 100-gram (3.5-ounce) serving. Edamame, tofu and soy milk are complete vegan proteins (Hughes et al. 2011). Beans and lentils are good sources of incomplete protein, with the added benefits of high fiber and B vitamins.

Indirect Animal Sources:

• A large egg has 6 grams of protein, with nearly equal amounts in the yolk and white (USDA 2013).

• Six ounces of yogurt has 6 grams of protein. Most Greek yogurts contain double the protein of regular versions. Yogurt also is a good source of calcium, B vitamins and live active probiotic cultures (NYA 2013).

• A cup of milk contains nearly 8 grams of protein.