More protein = more muscle. Right? Wrong.
Proteins are absolutely vital to the human body. We use 20 amino acids (the building blocks of proteins) to create body structures and enzymes and to regulate and maintain body functions. Proteins are needed for muscle tissue but the more = better idea is only true until you reach the amount your body needs and can utilize which, for most North Americans, is no difficult feat.
The Recommended Dietary Allowance (RDA) for protein is about 8-10% of total calories. Endurance athletes may need more than the average consumer but the U.S. Dietary Guidelines recommend no more than 35%. (Generally 10-35% is considered a healthy range.)
To give you some perspective, two 3oz servings of meat (one 3oz serving is about the size of a deck of cards or the palm of a woman’s hand) is enough protein to meet all of a man’s daily protein requirements. Considering the amount of meat most restaurants serve on one plate, you could easily be eating more than your full day’s requirement for protein in one meal.
What happens when you eat more protein than your body can use?
The same thing that happens when you eat too much of any energy source than your body can use: it gets converted to fat and stored in adipose tissue. With this in mind, unless you are training for a marathon on a daily basis, you might want to reconsider shoveling out the scoops of concentrated protein powder and chugging “muscle milk” on a regular basis. (Even if you are a marathon runner you might want to stick mostly to good old-fashioned food.)
Gaining weight is not the only repercussion your body suffers from a regular protein overload. The amino (Nitrogen-containing) portion of the amino acids in protein, get cleaved off from their carbon skeletons and sent to your kidneys as urea to be excreted in urine. Consuming too much protein regularly will place an undesirable burden on your kidneys.
Please note that it is rare for people to reach a dangerous level of protein consumption (one that taxes your kidneys) by simply eating food. This problem is far more likely with the use of protein supplements or concentrated powders. In general, if you are eating two hamburgers at lunch and a steak with cheese at dinner, you will probably just gain weight and develop increased stores of fat in your adipose tissue.
Healthy Protein Goals
Try to meet your daily protein needs by consuming proteins from a variety of food sources including lean meats, low-fat dairy, nuts, legumes, grains, fruits, and vegetables. If you are a vegetarian or vegan, check out The Dish on Proteins: Part II tomorrow to learn more about complete vs. incomplete proteins and how to get reach an adequate protein intake from non-animal sources.
Reference: Wardlaw’s Perspectives in Nutrition, 8th Edition