By Roberta H. Anding, MS, Baylor College of Medicine and Texas Children’s Hospital

Edited by Kate Findley and proofread by Angela Shoemaker, The Great Courses Daily

Current popular diets such as the keto diet encourage people to eat more protein while cutting carbs from their diet. Not only are they depriving themselves of an essential macronutrient, but their efforts can be counterproductive and wasteful, as Professor Anding explains.

Myths of High-Protein Diets

As important as protein is, we should not overemphasize protein while neglecting carbs and other essential macronutrients. Many people in the health and fitness world, particularly competitive athletes, have fallen for the trend of restrictive high-protein diets that leave them malnourished in the long run. 

“I worked with an athlete who had the belief that if he ate more protein, that would translate into more muscle, and more muscle would translate into better performance,” Professor Anding said. 

In the mornings, this athlete would have a protein shake. He would look for the protein shakes that had the least amount of carbohydrate and the highest amount of protein. 

Similarly, at lunch, he would concentrate on chicken, fish, or red meat and just put a few vegetables on the side. His belief was that eating more protein would translate into more muscle mass. 

What actually ended up happening was that his performance on the field was compromised. He didn’t have enough carbohydrate, which is the preferred fuel of exercising muscle. 

According to Professor Anding, the bottom line was that he needed to reorder his diet. Protein was important, but it could not be important at the expense of carbohydrate.

How Protein and Carbs Connect

Protein is a source of energy, but it shouldn’t be highlighted as a primary source. In fact, carbs are your primary fuel source. The primary intent of protein is not to provide energy, but to support your immune system, facilitate digestion, and aid in fluid balance.

Many athletes consume large amounts of protein while cutting back on carbohydrates because they believe it will help them lose body fat and enhance their performance. However, if carbohydrate is deficient in your diet, protein is sent to the liver. 

Nitrogen, which is the element that makes protein unique, is stripped off of the protein compound, and the remnant—that amino acid without the nitrogen—can be turned into carbohydrate in our liver. Thus, athletes who believe that they are creating more muscle by eating lots of protein while cutting carbs are actually sending that protein to their liver to make carbohydrates. The problem is that it can’t keep up with the demand for overall calories, and so they can experience significant fatigue.

One of the biggest mistakes people make in the athletic world is believing carbohydrates are evil. They ramp up their protein intake, not realizing that what they’ve done is to take expensive protein supplements, which just get sent to the liver, limiting the energy fuel source needed for muscles due to the lack of carbohydrates. 

It’s like trying to heat your house, and instead of using traditional fuel, you decide to throw $100 bills into your fireplace. Again, protein is designed for the building and repairing of tissue, not to use as an energy source. 

Protein does help you, though, when it comes to weight management. This is because protein leaves your stomach slowly, creating a sense of fullness or satiety. 

When introducing more protein into your diet, however, you should not severely limit your intake of carbs or fat. All of these macronutrients are needed for balanced health and optimal energy.

This article was edited by Kate Findley, Writer for The Great Courses Daily, and proofread by Angela Shoemaker, Proofreader and Copy Editor for The Great Courses Daily.

Professor Roberta H. Anding is a registered dietitian and Director of Sports Nutrition and a clinical dietitian at Baylor College of Medicine and Texas Children’s Hospital. She also teaches and lectures in the Baylor College of Medicine’s Department of Pediatrics, Section of Adolescent Medicine and Sports Medicine, and in the Department of Kinesiology at Rice University.