Picking Proteins

Proteins are an essential part of the diet, whether you're a patient on dialysis, an elite athlete, or simply struggling to lose weight.

It's important to understand that proteins do much more than build muscle. Many proteins are enzymes, which serve to catalyze reactions and impart a vital role in metabolism. Proteins are also involved in immune response and cell signaling.

The trick is eating enough protein to repair muscles after strength training workouts, maintain lean body mass, and, of course, keep your body functioning properly. Eating too much protein is like eating too much of anything - it gets stored as fat in adipose tissue. There is so much information out there about which proteins to eat, how much, when/what quantity after a workout - it can be very overwhelming.

The first thing to figure out is how much protein you should be getting per day. This is based on gender, amount and type of physical activity, and existing body weight.  For the general population that exercises at a moderate intensity most days of the week (light-moderate strength training), the recommended amount of protein is 0.8-1.0 g/kg of body weight. Yes, that is in kilograms. To find out how many kilograms you weigh, take your current weight in pounds in divide by 2.2. For example, a 170 pound man would weigh 77.3 kg. This means that he would need somewhere between 62 and 74 grams of protein per day. Because he is a male, I would go for the higher (74) number. Athletes inherently need a little more protein. Endurance athletes - those actively training or competing in triathalons, Iron Man, or even marathons - should consume 1.4-1.6g/kg body weight (http://www.ncbi.nlm.nih.gov/pubmed/15212749). The self proclaimed "body builder" at the gym should consume 1.2-1.4g/kg body weight. If he or she is seriously competing in body building or fitness competitions, there is a good chance that they are on a carbohydrate or energy restricted diet. In this case, the protein requirements would increase to at least 1.6g/kg body weight. It is also recommended that athletes on a carbohydrate or energy restricted diet see a Registered Dietitian to ensure that they are meeting their vitamin and nutrient needs.

Ok, now to choose which proteins are best for you. If you're a vegetarian, you can go ahead and skip to the next paragraph. For the meat eaters out there, it is important to first establish the concept of lean proteins. While some brands can legally call their meat lean based on federal guidelines, I usually advise clients who are looking to lose weight to stick to proteins that are 3 grams or less fat per 3 oz serving. Athletes or those looking to maintain or gain weight can choose proteins that range from 5-9 grams of fat per 3 oz serving. A 3 oz serving of meat is roughly equivalent to the size of a deck of cards. "Extra lean" proteins include standard chicken breast or chicken breast tenderloins, 99% lean ground turkey, and lean fish such as tilapia, basa, cod, and ahai tuna (albacore tuna for some reason has more fat).  The "lean" proteins are more like 93% lean turkey, swordfish, catfish, albacore tuna, and chicken sausage links. Salmon is an important exception because it contains a large amount of omega-3 fatty acids. Even though this fish is higher in fat, it is unsaturated fat, which has been shown to have less of a detrimental effect on cardiovascular disease. Proper amount of omega 3's can help to lower blood triglyceride levels as well, which is beneficial for your health. The American Heart Association (http://www.heart.org/) recommends that healthy adults consume fish at least 2 times per week, especially coldwater fish such as salmon. The AHA also recommends consuming plant foods that are a good source of omega-3 fatty acids, such as canola oil, flaxseed oil, and walnuts.

Biological value is another important concept related to choosing proteins. The biological value denotes how much of the protein ingested in a food will actually be utilized in the body. The closer the biological value is to 100, the more the proteins can be utilized by the body for rebuilding muscle, enzymatic reactions, etc. Whey protein and whole soybeans have a biological value of 96; eggs 94; soy milk 91; cow's milk 90;  fish has a BV of 76; beef 74; and whole grain flour of 64.  As you can see, soy actually has a pretty high biological value as compared to animal proteins.

Iron content is the next topic. Iron is an essential component of proteins involved in oxygen transport. Therefore, if you are iron-deficient, you may feel fatigue as your cells are not getting the oxygen that they need. There are two forms of dietary iron: heme and non-heme iron. Heme iron is found in animal proteins; non-heme iron is found in plant-based proteins. What's the difference? You absorb more of heme iron than non-heme iron. This is bad news bears for vegetarians. The current iron recommendations are actually based on the assumption that 75% of all iron you consume is heme iron - some sources cite that vegetarians should consume double the current recommendations for iron to ensure that they are able to absorb the proper amount. In today's world, a lot of grain foods such as cereals are fortified with iron, that is, they have iron added back in.  The current RDA (recommended daily allowance) for males and females ages 19-50 is 8 and 18 mg per day, respectively. To give you an idea of how much iron is in commonly eaten foods: Chicken liver (high in fat and cholesterol!), 3 1/2 oz yields 12.8 mg of iron; 6 oysters = 4.5 mg; light meat turkey, 3 1/2 oz = 1.9 mg; instant fortified oatmeal, 1 cup = 10 mg; mature soybeans, 1 cup = 8.8mg; 1/2 cup raw firm tofu = 3.4 mg. [http://ods.od.nih.gov/factsheets/iron].

The last lesson is of the greatest importance for vegetarians: choosing complementary proteins. Animal proteins are complete proteins, that is, they have all of the essential amino acids in adequate amounts. An essential amino acid is one that our body does not make on it's own - isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine (there are other amino acids that are conditionally essential based on age or genetic deficiencies). For lacto-ovo-vegetarians, eggs and dairy can provide complete proteins as well as necessary vitamins and minerals. For those with a stricter diet or for vegans, soy and quinoa are complete proteins, although soy has a higher biological value. There is a wide variety of soy products to choose from, ranging from tofu, soybeans, edamame (immature soybeans), soy milk, tempeh, and soynuts. The bulk of the vegan and vegetarian diet is composed of whole grains, fruits, vegetables, and nuts, seeds, legumes. These are all of great importance in terms of getting adequate vitamins, minerals, and even protein. Whole grains, nuts, seeds, beans, and legumes are called incomplete proteins, that is, they do not contain sufficient amounts of all the essential amino acids. Grains are missing a key amino acid. Beans are missing a key amino acid. Nuts are also missing an amino acid. But have no fear! When eaten together, these food groups complement eachother to give your body the full, complete protein and all essential amino acids.

I hope this article has shed some light on the basics of choosing the right protein for you. We've covered the basics: choosing the right amount of fat in your protein, choosing proteins with high biological value,  iron content and absorption, and lastly, choosing complementary proteins. Everyone has different needs, preferences, and tastes - it's your dietitian's job to design a meal plan that fits YOU.

Questions? Email me at rachel@stepupfns.com. I'm happy to answer questions and get feedback. :)