High protein diets: myths, half truths and outright lies


Without a doubt, protein is the king of all nutrients. It provides the building blocks for enzymes and hormones, enables nerve and brain cells to communicate effectively with each other, and promotes muscle tissue repair and growth. Every cell in your body contains proteins; life could not go on without him.

Protein consumption, however, is perhaps the most controversial of all nutritional issues. Unfortunately, many nutrition professionals have not kept up with recent research and continue to defend outdated theories on the subject. This has led to a series of myths that, in turn, have been taken as gospels 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 add to the pounds, 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 eat too much, you will eventually end up getting fat.

In reality, if you were to eat a meal that contains 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 process of digestion. This is called the thermic effect of food. Of all the macronutrients, protein has the highest thermal effect, burning about 25 percent of protein from calories consumed. By comparison, only 15 percent of carbohydrate calories are burned through digestion; fat has practically no thermal effect. So, all things being equal, a high-protein diet is less likely to cause fat deposits 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 main purpose is to neutralize blood sugar, it is also responsible for transporting fat to adipocytes (fat cells). When carbohydrates are ingested, 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 wildly, increasing the possibility of fat storage. Since the effect of proteins on insulin secretion is negligible, the potential for fat storage is reduced.

In addition, the consumption of protein 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 are bad for the kidneys.

Done: Protein metabolism involves a complex sequence of events for proper assimilation to occur. During digestion, protein is broken down into its components, amino acids (through a process called deamination). A by-product of this occurrence is the production of ammonia, a toxic substance, in the body. Ammonia, in turn, is rapidly converted to the relatively non-toxic substance urea, which is then transported to the kidneys for excretion.

In theory, a large buildup of urea can overload the kidneys and affect their ability to perform vital functions. This has been supported by studies in people with existing kidney disease. It is well documented that a high protein diet exacerbates uremia (kidney failure) in those on dialysis (i.e. 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 millions of athletes have consumed large amounts of protein over the past century without incident. Surely, if high protein diets caused kidney disease, these athletes would already be on dialysis. However, in otherwise healthy individuals, no peer-reviewed journal has documented kidney abnormalities due to increased protein intake.

On the other hand, drinking large amounts of fluids is beneficial when consuming a high protein diet. This helps clean 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 fat.

Done: Most Americans get their protein from red meat and dairy products, foods that are high in saturated fat. High-fat protein sources, such as bacon, ribeye, hard cheeses, and whole milk, are staples of the American diet. What’s more, keto “diet gurus” like Dr. Robert Atkins encourage the consumption of these products, promoting them as viable dietary options. Consequently, high-protein diets have become synonymous with the intake of fats that clog the arteries.

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 legumes are great low-fat protein options. By simply choosing the “right” foods, you can maintain a high protein diet with minimal effect on your fat intake.

Additionally, it is important to realize that certain fats, specifically unsaturated omega fatty acids, are actually beneficial for your well-being, as they aid in the absorption of fat-soluble vitamins and facilitate 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 excellent 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 cancers.

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 television addicts. 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 actually 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 of protein), there is a decrease in protein synthesis throughout the body, indicating a catabolism of muscle tissue.

On the other hand, it is unwise to ingest huge amounts of protein in the hope that it will enhance athletic performance. Bodybuilders often subscribe to this “more is better” philosophy and gorge themselves on protein-rich foods and supplements (one popular bodybuilder claims to ingest 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 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 is also important to realize that protein alone has no effect on muscle gains. Contrary to what many supplement manufacturers claim, protein powders are not magic bullets for building muscle. You can’t expect to just have a protein drink, sit back, and watch your muscles grow. This may be good advertising copy, but it does not translate into reality. Only through intense strength training can protein be used for muscle repair and promoting the development of lean muscle tissue.