T Nation

LA Times Article

High-Protein Diet Hinders Athletes

By Martin Miller, Times Staff Writer

Athletes who adopt a high-protein, low-carbohydrate diet may hurt their performance, not enhance it, sports nutritionists say.

For years, such diets have attracted throngs of athletes, from high school to professional levels, who seek to build muscle and drop unwanted pounds.

Although conceding that the diet may well lead to weight loss, sports nutritionists warn that it may not be the kind of weight athletes want to lose.

Instead of taking off fat, athletes on the diet who train vigorously and compete regularly probably are shedding muscle mass.

“It’s a trendy diet that is a big mistake for athletes,” said Chris Rosenbloom, an associate professor of nutrition at Georgia State University. “They find out eventually that their body’s run out of fuel too quickly.”

The mainstream appeal of many low-carbohydrate diets has helped promote the popularity of similar eating programs among athletes, who are constantly seeking a competitive edge.

Leading health and fitness magazines reinforce the diets’ appeal by bombarding athletes with ads trumpeting “carb-free” energy drinks, “zero-carb” energy bars and low-carb nutrition shakes.

But carbohydrates are essential to athletic performance because they are converted into glucose, which is needed to power muscles. Carbohydrates stimulate the production of insulin, which helps release amino acids into muscles so they can be built, maintained and repaired.

Carbohydrates also supply more energy for muscles ? and do it more efficiently ? than either proteins or fats, nutritionists say. Eating enough carbohydrates is crucial for almost any activity ? regardless of the fitness level of the athlete ? especially if the exerciser has low body fat and is unable to call upon fat reserves for energy.

Nutritionists also caution athletes against accepting dietary recommendations from personal trainers who don’t have proper credentials or certifications.

“You want your diets based on research,” said Rosenbloom, who has consulted with the Atlanta Hawks pro basketball team. “Not on what some guy tells you at the gym.”

Although athletes differ, sports nutritionists say a good general guideline for a sports diet is to consume 5 to 7 grams of carbohydrates and 1.2 to 1.5 grams of protein for each kilogram of body weight. (In nonmetric terms, the equivalent is 0.16 to 0.22 ounces of carbohydrate and 0.04 to 0.05 ounces of protein for each 2.2 pounds of body weight.)

At minimum, athletes need to eat at least 500 total grams (about a pound) of carbs each day. “You don’t want to eat Cap’n Crunch for breakfast,” she added. “Oatmeal will work.”

Any opinions? Isn’t that A LOT of carbs? But I guess it depends on how hard the athlete is training…

I agree with the article. The T-dawg diet (and types like it) are good for cutting, but not for athletics. Just ask any athlete who has tried to compete consistently on a low carbohydrate diet. It just doesn’t work well for performance.

Wouldn’t it be more accurate to say that a low carb diet is bad for athletes?

Protein is essential for building and maintaining muscle. So long as consuming a high protein diet doesn’t mean also cutting carbs I see no problem.

Here in lies the rub. To perform at an optimal level as an athlete, your bodyfat needs to be in the 5-7% range. Poliquin likes to have his athletes around 6% or lower. Most of the population is carb intolerant so you really have to manipulate the diet to gain a balance.

I agree with the article 100%! It stands to reason that for ATHLETIC purposes, one needs the added CHO’s for performance (especially if one is in season). However, if you are a bodybuilder preparing for a show, trying to lose that extra body fat, well…t-dawg is very beneficial and CHO’s need to be restricted to a certain extent

Funny how there is plenty of evidence, both anecdotal (see Steve Maxwell, of Maxercise and his low carb diet for MMA and BJJ) and documented (look at Natural Hormonal Enhancement and Enter the Zone) that says otherwise.

It would be much better to say that an “optimal” carb diet is best for athletics, with the optimal levels of carbs tailored to the athlete, his response to CHO intake, and the needs of his sport.

Personally, I’ve performed just as good on a regular, high carb diet and the anabolic diet during two consequetive rugby seasons.


I eat according to my needs. I take in consideration my work schedule and also my training schedule.

BTW: most athletes, IMO, are pretty clueless when it comes to their nutritional needs. It’s a rare thing to find an athlete who is completely aware of what they’re needing nutrition-wise.

When boxing, you better believe I need carbs. I also need protein to maintain also needed LBM. I just eat. If I feel sluggish, it usually mean I’m not eating enough or did not eat enough carbs.

I gotta say, it’s really not rocket science to eat for your needs.

I’m going to agree with Patricia on this one. If you’re eating for your needs it isn’t rocket science.

However, if you’re eating for a bodybuilding show or a competitive sport you need to be a little more calculating. Bodybuilding requires less carbs while cutting. Athletic performance requires more. Take, for example, the world cycling championships that just took place in my home town. If those guys who are riding at a high % of VO2 MAX for 6-7 hours didn’t consume enough carbs they simply wouldn’t complete the race.

So…carbs for performance? Sure. Carbs for getting VERY lean? Not necessarily.


pity that most top performing athletes aint 5-7% and there is no research showing lower bf% perform better.

Carb intolerant my ass, most of the population is just over eating under exercising fat asses

I think your off base, cycomiko. There are studies that show the lower your bodyfat is, the faster you will perform in the 40 yard dash and also in agility drills. It makes sense to carry as little fat as possible, since it serves no function athletically.

Also, carb intolerant means that most people don’t handle carbs well and are stored as fat.

Take care cycomiko,


ok, provide the research that shows 5-7% must be attained for maximal performance. Never mind the fact that a natural athlete getting to that level will screw up their hormones to an extent.
Excess bodyfat can potentially reduce the ability in certain activities (jumping running) but try to find much research on it.

Carb intolerant is a term coined by Poliquin, strange that no one else in the world knows it.

I’m not sure exactly how being 5-7% would help in many sports. Granted, carrying less fat would allow people to run faster and jump higher. However, muscle mass would also theoretically slow someone down as it can weigh more than fat.

IMO this that article is next to useless, way too much generalization.

So she’s saying that any athlete needs at least 500g/day of carbs regardless of type of activity, activity level, and bodyweight/composition?

It’s these types of articles that keep the pendulum swinging…

But, muscle moves bone, fat does nothing, at least athletically speaking.

Keep in mind that I said THEORETICALLY muscle weight could decrease performance. I mean, increased upper body muscle mass would do very little to increase running speed.

Your upper body must be strong enough to propel your legs. That is why muscle balance is so important when it comes to running fast. Most sprinters have very strong upper bodies. Ben Johnson benched close to 400 pounds, as an example. Check out the Charlie Francis Training System book. I know Charlie P. is fond of bringing up the upper back development of a lot of his athletes as he finds it as on the weak links.


I never heard of Johnson benching close to 400lbs. I would love to know where you got that piece of information.

Keep in mind I don’t doubt your sincerity in stating this. I heard that in his prime Carl Lewis could squat 400lbs for reps. However, I never saw it authenticaed. It is just something that I heard.

Poliquin says a strong upper back is essential for speed.

Ben Johnson: bench 450x2


What is the source of your information? If you could let me know the magazine, journal, book whatever, I would appreciate it.

I think that is amazing for a sprinter!