Written by Alexis Lago
02 December 2009

  Protein vs. Carbohydrate for Performance: A Debate

By Carlon M. Colker, M.D.

 

If you ask me, ignorance sure ain’t bliss, especially when it comes to deciding between carbohydrates and protein for performance. Things used to be a whole lot simpler when everyone just blindly subscribed to the same simplistic belief that carbohydrates equal energy. But lately, rabble-rousers (like myself), along with several of my colleagues, are raising new comparative questions with regard to carbohydrate versus protein for performance. In the process, we’ve raised more than few eyebrows. Unfortunately, many other experts in the field of sports performance think I’ve lost my marbles at a ripe young age. Sorry fellas, it’s not pre-senile dementia I’m experiencing. Rather, a cutting edge “Greenwich Diet” approach (check out my latest book) to sports performance in which carbohydrates play a virtually insignificant role.

My theory is fairly logical and straightforward. Protein, in combination with sufficient quantities of healthy fats, fluids (water) and complete-protein-incomplete-proteins.jpgvitamin/mineral supplementation, virtually eliminates the need for carbohydrate-based foods. Even though the Greenwich Diet focuses on achieving a healthy diet for disease-free living with a byproduct of amazing body fat loss, the same model can be extrapolated and applied to the performance athlete. The only difference is that the intake of these nutrients increases significantly in frequency, primarily depending on the athletic event; how “aerobic” your training is versus how much explosive resistance work is involved; body size and composition; and gender.

 

In any event, others don’t necessarily hold to the same beliefs. Let’s explore some differing opinions on the subject and see how some of my colleagues lock horns with the subject. 

 

William Kraemer, PhD

 

“Carbohydrate does provide a more immediate energy boost in some situations, [but] protein can be burned as a fuel. How efficiently [this happens] depends on the athlete’s dietary regime, the training status of the athlete, and the demand of the exercise challenge.

“The competitive athlete has a much bigger stake in the dietary choices he makes because of the fact that small gains in performance translate to medals, place winnings, and money versus your weekend warrior who is going for personal interest. [However], the public is so overwhelmed with misinformation because we’re trying to make things global and big and they’re not that way.

“We find that branch chain amino acids (BCAAs) are very effective in helping people during very strenuous resistance training programs.”

 

Jeff Volek, PhD, RD

 

“Carbohydrate is more efficient to burn as a fuel and I don’t think too many people would argue that it’s beneficial to burn protein. It’s a misconception that a lot of these low-carbohydrate diets are not necessarily high-protein diets— they’re high-fat diets. For athletes, the literature is focusing more on high-fat vs. high-carbohydrate diets.

“You get above two grams PRO (protein) per kilogram of body weight per day and it doesn’t contribute to protein synthesis anymore. It just becomes a fuel source, so you get increased oxidation of protein beyond that level; in that respect, you might as well give the extra calories as carbohydrate or fat. There’s certainly an upper limit that’s shown by nitrogen balance studies. 1.7 to 1.8 grams PRO/kg BW/day is more appropriate for weight training athletes compared to the RDA which is 0.8 g PRO/kg BW/day.

“The real question is one of which diet is better for endurance performance — high-fat or high-carbohydrate? That’s the real question.” 

 

Colker comment: Bravo. I agree.

 

“We don’t have too much evidence to support a high-protein [high-fat, low-carb] diet for athletes.”

 

Colker comment: But a recently completed study by Volek and Kraemer (in press) fed a “ketogenic diet” to athletes for eight weeks to determine the effect on their lipid profiles. The diet consisted of 65 percent fat, 10 percent CHO, and 25 percent PRO. They found that the diet did not cause any damage to the kidneys. Volek’s “gut instinct” is that this diet is safe to follow long-term; however there is no long-term data (over several years) to prove that. 

 

“We validated that [no negative effects occurred in the body secondary to being in a constant state of ketosis] with both urinary ketones and blood beta hydroxy butyrate, which is a primary ketone in the blood.”

 

Thomas Fahey, PhD

 

 

“Diets high in carbohydrates give athletes better endurance when compared to high-protein, low-carbohydrate diets.”

“Yes, protein contributes about 15 percent of fuel flux during exercise, but it isn’t as efficient as carbohydrates. The body can use ketones— they’re just slower [referring to a “ketogenic diet]. Carbohydrates are the preferred body fuel— they are much faster than protein or fats in terms of oxygen consumption— and that’s what a weekend warrior wants [a fast energy source].

“The average intake [of protein] for anaerobic athletes, such as football players, is two grams PRO/kg BW/day. I recommend 0.8 to 1.5 g PRO/kg BW/day for any athlete (approximately 15 percent of total calories as protein, 20 to 30 percent calories as fat, and the balance from carbohydrate. Greater than 1.5 g PRO/kg BW/day is not necessary.”

 

Colker comment: Fahey describes a high protein diet as having more than 15 percent of calories from protein.

 

       “A recent study from the Netherlands gave athletes four grams PRO/kg BW/day.  There was no danger of kidney damage. However, this is only one study and the data has not been reproduced.

“Endurance athletes like marathoners and endurance cyclists need a high-carbohydrate diet. Insulin stimulates the sodium-potassium pump, which is involved in transporting amino acids in muscle. The timing of protein intake with weight training athletes is really important. So, raising the insulin level after exercise and keeping it there for one hour post-exercise (during recovery) speeds the transport of amino acids into muscle cells.  Providing carbohydrate-protein drinks post-workout raises insulin and other growth factors such as IGF-1 and growth hormone, creating an anabolic hormonal environment for building muscle.”

 

Richard Kreider, PhD

 

       “Protein can be burned as a fuel, to a small degree. There are specific amino acids, such as branch chain amino acids, glutamine and aspartate, that contribute to glucose production, but protein is not a preferred fuel [by the body]. It does not matter what kind of exercise you do— weight training or aerobic exercise— we recommend 1.5 to 2.0 g PRO/kg BW/day for athletes in order for them to gain muscle mass. Athletes training at high altitudes may need as much as 2.2 g PRO/kg BW/day in order to maintain nitrogen and protein balance.

“While I would define a high-protein diet as greater than 2.2 g PRO/kg BW/day, the maximum protein level would be not greater than 2.2 g PRO/kg BW/day, while the average American needs  approximately 1.0 g PRO/kg BW/day.

“Athletes are susceptible to protein depletion, particularly those athletes who are trying to lose weight for a competition— gymnasts and wrestlers. But if an athlete takes in more protein than the body needs, that extra protein is not going to help [enhance performance]. The optimum level of protein for athletes (in order to gain muscle mass) is 1.5 to 2.0 or 2.2 g PRO/kg BW/day.

“We recommend high quality, complete protein. The best source is whey protein.  Particularly post-exercise, we provide protein/carbohydrate drinks and energy bars— for convenience, not because they’re better— to enhance anabolism. We recommend a 3:1 ration of CHO:PRO (carbohydrates to protein) in post-exercise drinks/energy bars.”

In terms of high protein diets causing kidney damage, Dr. Kreider says, “That’s more of a wives’ tale. A recent study provided 2.5 g PRO/kg BW/day for one or two months. It showed no impact on kidney function in previously healthy adults. But there is no clear long-term data verifying the effects of a high-protein diet.”

 

Well, it looks as if my colleagues and I are at odds. Not surprisingly, they take a much more traditional view of the importance of carbohydrates. As such, carbohydrates are considered the fuel for most body functions. My contention is that if your body is used to an influx of carbohydrates (most people are conditioned in this way) in order to satisfy your energy needs, this dependency will simply perpetuate itself in a narcotic manner.

Carbohydrates have become so important because we, as a society, have made them so. By stoking our furnaces with an excessive amount of dietary carbohydrates, we have in essence created a lazy path of least resistance. This sugar-coated trail allows our bodies to get away with ignoring the very efficient metabolic routes of fat burning for energy and protein utilization when necessary.

I believe our society has been sickened by an overabundance of carbohydrates in the diet.  For example, diabetes is considered one of the most common diseases known to man, yet I believe we as a society have made it so. If we didn’t pump ourselves and our children with carbohydrates from day one, most people with diabetes would live a normal life without ever knowing about or suffering from their condition. It’s the sugar that brings it out. We as a society have fooled ourselves into thinking carbohydrates are synonymous with energy. In a healthy body, nothing could be further from the truth.

This goes for athletes and performance as well. Remember, the more carbohydrates you eat, the more you will be dependent on them. I liken it to a drug addiction. Concentrate more on “healthy fats” (monounsaturated) for energy and whey protein for recovery and building, with only incidental carbohydrates finding their way into the diet in the form of high-fiber vegetables rich in phytonutrients. These are some of the basic key points in the Greenwich Diet.

 

Special thanks to Anita “Leila” Lynch, an intern rotating with me this month, for her work in collecting quotes for this piece.