Wednesday, July 13, 2011

PROTEIN

What is Protein?


Proteins, made up of amino acids, are the nutritional base for the building of lean muscle mass. Weightlifting results in small tears of muscle fibers. Amino acids repair these damaged muscle fibers and synthesize new, stronger fibers in the process. In order for muscles to properly recover and grow, amino acids must be constantly ingested.

There are 22 different amino acids:13 of these amino acids can be produced by the body. These are referred to as non-essential amino acids. The other nine, often referred to as essential amino acids, must be digested. Animal proteins, such as meat, dairy, and eggs provide all 9 of these essential amino acids, making them “complete proteins.”

When complete proteins (meat, dairy, and eggs) are absent or lacking from the diet, the body can still create complete proteins by combining incomplete ones, but this process is somewhat more complex and harder to achieve without a well-sufficient understanding of nutrition and food combining strategies.

For example, consuming legumes, nuts, and grains can create complete proteins, BUT it will require eating 25% more plant-based foods to achieve the same results as consuming animal protein. The primary concern with plant-based diets with regard to protein intake is that consuming increased levels of legumes, nuts, and grains will drastically increase carbohydrate and fat consumption in order to achieve minimal protein requirements. This situation may have negative effects when it comes down to the ultimate goal of weight-loss.


Protein Levels and Effect on Metabolic Rate


There are 3 major factors that determine one’s metabolic rate (keep in mind that metabolic rate is directly related to one’s ability to lose weight).


1) Resting Metabolic Rate: how many calories does your body need per day in order to sustain vital functions, including digestion. This rate also accounts for activity levels. Resting metabolic rate accounts for up to 70% of your metabolic rate.


2) Activity Level: How much do you exercise? How many days per week? What duration? What intensity level? This accounts for 10-30% of your metabolic rate (closer to 10% if sedentary and up to 30% depending upon exercise intensity and duration).


3) Thermal Effect of Feeding: Digestion uses energy and burns calories. The macronutrients you consume (carbohydrates, fats, proteins) all effect the body temperature necessary in order to digest the given food. The higher the thermal temperature required for macronutrient breakdown, the more calories will be burned during the digestive process.

Protein creates the highest thermal effect; the more protein consumed, the higher the body temperature during digestion. The higher the body temperature during digestion, the more calories burned during digestion. Carbohydrates rank second and fat creates the lowest thermal effect.


Take home note:


Complete proteins speed up your metabolism and result in a higher number of calories burned. Carbohydrates and fats do not yield the same results. This is another reason why plant-based protein combinations (which tend to yield higher amounts of carbohydrates and fats to sustain minimal protein levels) are often inefficient when it comes to achieving weight-loss goals.


Whey Protein


Branched Chain Amino Acids (BCAAs) are the best sources of protein available because the body can absorb them quickly and convert them into usable energy efficiently. BCAAs consist of three essential amino acids: leucine, isoleucine, and valine. Whey protein is 10% leucine, while other animal-based proteins contain as little as 5% leucine. The body recognizes leucine similarly to the way it recognizes hormones, so leucine intake actually stimulates protein synthesis more that other essential amino acids. This immediate protein source is taken up into to the bloodstream within only 15 minutes of digestion. This makes leucine ideal for pre-peri, and post-workout nutrition.


Casein Protein


Casein is found in dairy products. It is opposite from whey protein in that it digests and absorbs slowly. Casein is best for supplying the body with a small, slow and sustained release of protein. As a result, casein can fuel the body for longer periods of time. Casein best aids in muscle recovery and growth in between meals and during sleep. It is not uncommon to find whey and casein protein blends these days. Whey will immediately repair muscle while casein will provide a longer, slower synthesis of protein in between meals and at rest.


Egg Protein


Eggs are also high in leucine, making them a great source of energy when it comes to muscle recovery, increased muscle strength, and increased muscle and size.

The food we eat will have one of three fates: it will be integrated into the body (used for tissue repair, etc), stored as fat, or excreted. The wonderful thing about eggs is that the body can use 94% of the protein in a whole egg. This means that consuming eggs will pose little to no risk of increasing fat stores. Eggs will almost entirely be used as an energy source! SO, EAT UP!


Soy Protein


Soy does not show much benefit when it comes to increasing protein synthesis. In fact, the pitfalls of soy, compared with whey and casein, greatly out-number the benefits. Early research studies suggested that soy consumption could lower LDL (bad) cholesterol. However, recent research estimates that 2 pounds of tofu/day would have to be consumed in order to lower LDL cholesterol by 3%

Soy is full of isoflavins. Isoflavins promote increased estrogen levels and slow thyroid function when consumed at the levels necessary to minimally decrease LDL cholesterol (by 3%). High soy consumption has also been associated with lowered sperm count.

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