Without a doubt, protein is the king of all nutrients. It provides the building blocks for enzymes and hormones, allows nerve and brain cells to communicate effectively with each other, and promotes the repair and growth of muscle tissue. Every cell in your body contains protein; life could not go on without him.
Protein consumption, however, is perhaps the most controversial of all nutritional topics. Unfortunately, many nutrition professionals have not kept abreast of recent research and continue to espouse outdated theories on the subject. This has given rise to a number of myths which, in turn, have been taken as gospel by the general public. The following are some of the most common misconceptions about dietary protein intake:
Myth: Diets rich in protein make you fat.
done: There is no doubt that eating too much protein will gain weight, but so will eating too many calories from carbohydrates or fat! Weight gain is governed by the law of thermodynamics: if you consume more calories than you expend, you will gain weight. Consequently, it is not protein per se that causes weight gain; It is an excessive consumption of calories. No matter what you eat, if you consume too much, you will eventually end up getting fat.
In reality, if you were to eat a meal that contained only protein, carbohydrates, or fat, the protein meal would cause the least amount of weight gain. You see, a large percentage of the calories from protein are burned in the digestion process. This is called the thermic effect of food. Of all the macronutrients, protein has the greatest thermic effect, burning about 25 percent of the protein in calories consumed. By comparison, only 15 percent of calories from carbohydrates are burned in digestion; fat has virtually no thermal effect. Therefore, all other things being equal, a high-protein diet would be less likely to cause fat accumulation than a high-carbohydrate or high-fat diet.
Also, unlike carbohydrates, protein does not stimulate a significant insulin response. Insulin is a storage hormone. While its primary purpose is to neutralize blood sugar, it is also responsible for transporting fat to adipocytes (fat cells). When carbohydrates are eaten, the pancreas secretes insulin to remove blood sugar from the circulatory system. Depending on the amounts and types of carbohydrates consumed, insulin levels can fluctuate greatly, increasing the possibility of fat storage. Since the effect of protein on insulin secretion is negligible, fat storage potential is decreased.
In addition, protein consumption tends to increase the production of glucagon, a hormone that opposes the effect of insulin. Since a primary function of glucagon is to signal the body to burn fat for fuel, it tends to promote fat loss, rather than fat gain.
Myth: High-protein diets damage the kidneys.
done: Protein metabolism involves a complex sequence of events for proper assimilation to occur. During digestion, protein is broken down into its component parts, the amino acids (through a process called deamination). A byproduct of this occurrence is the production of ammonia, a toxic substance, in the body. Ammonia, in turn, is rapidly converted to urea, a relatively non-toxic substance, which is then transported to the kidneys for excretion.
In theory, a large buildup of urea can overload the kidneys and impair their ability to carry out vital functions. This has been supported by studies in people with existing kidney disease. It has been well documented that a high-protein diet exacerbates uremia (kidney failure) in those on dialysis (ie, the artificial kidney machine), while a low-protein diet helps alleviate the condition. Proteinuria and other complications have also been observed in this population.
However, there is no evidence that a high-protein diet has harmful effects in people with normal kidney function. Healthy kidneys can easily filter urea; any excess is simply expelled in the urine. Consider the fact that, over the last century, millions of athletes have consumed large amounts of protein without incident. Surely, if high-protein diets caused kidney disease, these athletes would already be on dialysis. However, in healthy individuals, no peer-reviewed journal has documented kidney abnormalities due to increased protein intake.
On the other hand, it is beneficial to drink large amounts of fluids when consuming a high-protein diet. This helps cleanse your system and facilitates the excretion of urea from the body. For best results, a daily intake of at least one gallon of water is recommended, drinking small amounts throughout the day.
Myth: High-protein diets result in excessive intake of unhealthy saturated fats.
done: Most Americans get their protein from red meat and dairy products, foods that are high in saturated fat. High-fat sources of protein, such as bacon, ribeye, hard cheeses, and whole milk, are staples of the American diet. Additionally, ketogenic “diet gurus” like Dr. Robert Atkins encourage the consumption of these products and promote them as viable dietary options. Consequently, high-protein diets have become consistent with intake of artery-clogging fats.
However, there is no reason why a high protein intake should be derived from cholesterol-laden foods. There are many sources of protein that contain little or no saturated fat. Skinless chicken breasts, egg whites, and vegetables are great low-fat protein options. By simply choosing the “right” foods, you can maintain a high-protein diet with minimal effect on fat intake.
Additionally, it’s important to realize that certain fats, specifically omega-unsaturated fatty acids, are actually beneficial to your well-being, aiding in the absorption of fat-soluble vitamins and facilitating the production of various hormones, cell membranes, and prostaglandins. These “essential” fats cannot be manufactured by the body and therefore must be obtained through nutritional means. Cold-water fish (such as salmon, mackerel, and trout), tofu, and peanut butter are protein-based foods that are also great sources of essential fats. Its consumption has been shown to have a positive impact on cardiovascular health and reduce the risk of various types of cancer.
Myth: High-protein diets are unnecessary for athletes.
done: If you believe the United States Department of Agriculture (USDA), there is no difference in protein requirements between athletes and couch potatoes. This is reflected in the RDA for protein, which is the same for all individuals regardless of their activity levels.
However, contrary to the USDA position, studies have shown that athletes require more protein than sedentary people. When you exercise, protein stores are broken down and used for fuel (through a process called gluconeogenesis). Branched-chain amino acids (BCAAs), in particular, are preferentially mobilized as an energy source during intense training, as are alanine and glutamine. It has been shown that when athletes consume a low-protein diet (equivalent to the RDA for protein), there is a decrease in protein synthesis throughout the body, indicating catabolism of muscle tissue.
On the other hand, it is unwise to ingest huge amounts of protein in the hope of improving athletic performance. Bodybuilders often subscribe to this “more is better” philosophy and gorge themselves on high-protein foods and supplements (one popular bodybuilder claims to eat up to 1000 grams of protein a day!). Unfortunately, the body only has the ability to use a limited amount of protein. Once the saturation point is reached, the extra protein is of no use to the body and is either used for energy or converted to triglycerides and stored as fat. In general, optimal protein synthesis can be achieved by consuming one gram of protein per pound of body weight. Therefore, to maximize strength and performance, a 150-pound person should consume approximately 150 grams of protein per day.
It’s also important to realize that protein by itself has no effect on muscle gains. Contrary to what various supplement manufacturers claim, protein powders are not magic formulas for building muscle. You can’t expect to just consume a protein drink, sit back and watch your muscles grow. This could be good ad copy, but it doesn’t actually translate. Only through intense strength training can protein be utilized for muscle repair and promoting the development of lean muscle tissue.