Structure and Function: 

Proteins are one of the three major macronutrients. They are made of many smaller units called amino acids. Many amino acids of the same type or different types are bonded together to form the whole structure of a protein. Many proteins in turn are bundled together to form a muscle. Think of the muscle as a major cable where the proteins are the many wires in each cable and the amino acids are the individual copper strands and metals that form each wire. Most people think of proteins as the muscle building blocks, but we use proteins and amino acids in many other vital body functions such as the immune system, cell walls, cell signaling in brain function and many other hormonal and metabolic body functions. In fact, in states of protein malnutrition, our body breaks down its own muscles to make protein and amino acids for their other vital body functions. 

 

Digestion:

Proteins are broken down into their amino acids in our digestive system and then absorbed. Our body then uses those amino acids to make its own proteins. There are 15 amino acids; 9 are considered essential amino acids, meaning our body cannot make those amino acids, and they have to be in our diet. The other 6 are non-essential, meaning we can substitute other amino acids for them to build our body's protein, and they do not have to be included in our diet. As long as you eat a well balanced diet that includes more than one source of protein, you do not need to worry about including essential amino acids in your diet as they are already in almost all of the proteins we eat. In fact essential amino acid deficiency is only seen in cases of food starvation and in few very rare congenital diseases diagnosed shortly after birth.

 

 

Sources of Dietary Protein:

Proteins are all made of similar amino acids just arranged in different ways. So all proteins are healthy. But in nature proteins are found surrounded by fat. And this make sense. Remember that fats are one of the major sources of energy storage, and muscles are the power house where a lot of energy is needed. So, in nature muscle tissue (protein) is embedded with fat tissue. Have you ever noticed all the white fat in the steak before it is cooked? Therefore, what makes some proteins healthy and others unhealthy is the kind of fat composition that is in that meat. Let's look at each source of dietary protein:

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Fish: Healthiest source of meat. Fish meat is generally stored in very healthy fats. Hence, all fish are healthy. In addition, there are certain fish that are high in Omega-3 fatty acids which have tremendous health benefits. These include salmon, lake trout, sardines, catfish, shrimp, anchovies, and herring. Tuna is also very high in Omega-3s, however, tuna is also high in mercury. Mercury can be harmful to the growing brain and should be limited to 6 ounces per week in the at risk population: pregnant women, lactating women, and children. For others tuna should be limited to 12 ounces per week. 

 

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Chicken: Breast has the lowest fat, and thighs and wings have the highest fat (think about it; birds use their wings and legs to move, and the breast meat does not do as much work). So, if caloric restriction is a concern to you, choose breast, otherwise choose the part that is most tasteful to you.  

 

 

 

 

 

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Pork: Unprocessed pork is a great source of protein, vitamins and minerals. Pork is also rich in healthy fats: about 50% unsaturated and 50% saturated. But be aware of processed pork such as bacon and hot dogs which are rich in fat and devoid of most protein (another great example of a healthy natural food processed into a unhealthy food).  

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Red meat (Beef):  Red meat is packed with saturated fat and therefore is very high in calories. In addition, recent research is linking red meat consumption to increased risk of colorectal cancer; red meat changes the bacterial composition of our colon, promoting growth of certain bacteria that are now being associated with increased risk of developing colorectal cancer. But red meat also has some advantages: it has the highest content of protein per ounce, and it is rich in iron and certain vitamins. And although not as healthy as the fat in fish, recent observational studies do not correlate low red meat consumption with cardiovascular disease. Lastly, for some people it’s the most delicious meat of all.

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So, what is the bottom line on red meat? If you do not care much for red meat, then we recommend you eliminate it from your diet since there are many other protein rich options. But if like Babak, you salivate at the smell of your neighbor’s BBQ, then we have this suggestion for you: pick red meats with less fat in them. These include 90% lean ground beef and any red meat with the preface Loin or Round on it. We also recommend that you reserve your red meat for home cooking since most fast food and other restaurants will use lower quality and higher fat content meat to reduce costs. And if you really have to have your high fat content cuts like Ribeye or New York steak, then we recommend you only do this no more than one to two times a week to satisfy your palate without gaining too much weight. And lastly, according to the latest American Heart Association recommendations, you should limit your total consumption to no more than 18 ounces per week.

 

In addition, recent research has shown that the fat found in free-range, grass-fed beef and related dairy products, the way cattle were raised in the old farm days, is significantly different than the fat found in today’s industrial, corn fed and caged cattle. It is now well established that the fat in natural, grass-fed beef has a higher percentage of unsaturated (good) fat, a more beneficial profile of saturated fat, with more carotene, vitamins and antioxidants and fewer calories than meat from industrialized cattle. Although saturated fat is not as beneficial as unsaturated fat, in its natural form, it is not as harmful as once thought.  

 

Bottom line, if you do not care for red meat then you should eliminate it from your diet, but if red meat is an essential element of your diet then try and use products from free range, grass fed cattle. These can be purchased in farmers' markets, bought directly from farms, and also found in certain grocery stores. 

 

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Eggs: For a long time eggs were considered unhealthy because of their high cholesterol content. But we now know that the fat in egg is in fact quite healthy and beneficial. Each egg has about 8 grams of protein stored in the egg white and 160 grams of cholesterol stored in the yolk. In addition, egg yolk is packed with various vitamins. Egg is a terrific addition to your breakfast or your lunch salad. You may include 2-3 eggs per day in your diet, but if you suffer from elevated cholesterol, then we recommend only eating the egg white once you have reached the 7-egg limit per week.

 

  

 

 

 

 

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Dairy: Yogurt, cottage cheese, and to a smaller extent, milk, are all packed with protein. Dairy products also have saturated   fat.  However, recent research shows that the fat in dairy products may in fact be beneficial. If you prefer to limit your             calories, you can always choose non-fat, 1% or 2% for lower fat content. In addition dairy products are a great source of         calcium. Try to consume 1-2 servings in a day. 

 

 

 

 

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Vegetarian sources of protein:

In addition to animal protein, there are numerous other sources of protein with excellent nutritional value. Just talk to any vegetarian, and we are sure you will be able to obtain an extensive list of alternative protein sources and recipes. Here are few common vegetarian protein sources:

•  Beans & Chickpeas: high in protein, healthy carbohydrates, and minerals. One of the healthiest super foods you can eat. 

• Whole Grains: such as Quinoa, Farro and Barley. These are rich in complex carbohydrates and protein. 

• Lentil

• Tempe: high in protein and usually added to salads, yogurt or any other food. 

• Tofu: high in protein, easily cooked, and absorbs any food juice or sauce for added favor. 

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Unless you are already a vegetarian, you may be unfamiliar with this category of proteins. But let us tell you that having explored this category not too long ago ourselves, there are many versatile and easy to cook recipes for vegetarian cooking. These protein sources are delicious, much easier to digest, and significantly more economical than meat options. So we highly encourage you to start incorporating some vegetarian meals into your weekly plan. 

 

 

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Protein Supplements: You may have noticed that we have left out one common and wide-spread source of protein from this list: the many protein supplements and protein bars available in the stores. There is a reason for this: there is NO REASON for you to include this category of protein in your diet. These protein supplements are synthetic, unregulated, expensive, and worst of all, most of them are loaded with artificial sugars to make them taste better. The majority of us can get all the protein we need from healthy sources in our 3 meals and snacks. Even when training more than 14 hours per week for a long race or if you are looking to add 10 pounds of muscle, you do not need to use protein supplements. Simply increase your protein intake by snacking on healthy sources such as nuts, cottage cheese, and peanut butter.