This article was originally published in Nutrition Business Journal and is republished here with permission of NBJ.

Dean Karnazes, author of "Ultramarathon Man: Confessions of an All-Night Runner," is probably the best known athlete in an extreme endurance niche where a marathon is just a warm-up and events include the infamous 135-mile Badwater race across Death Valley in July. With an academic and professional background in food science and many thousands of miles of trial and error, Karnazes knows sports nutrition from the lab to the lunchbox. Nutrition Business Journal (NBJ) spoke with him from his home in Marin County, CA.

NBJ: What is your nutrition background?

Dean Karnazes: I actually studied dietetics as part of a minor in biochemistry at Cal Poly San Luis Obispo and then went into food science as a graduate student. So I was very interested in food formulation. I was an athlete in college and looking for ways to boost my performance, basically manipulating food in a way that is more concentrated and better for an athlete. This was back in the late 1980s, right when Brian Maxwell and his wife came up with PowerBar.

NBJ: Who were you working with?

Karnazes: I did some work with Balance Bar, with PowerBar, and I was doing a lot of formulation in the lab at Cal Poly. Cal Poly has a really incredible food science laboratory. They have test kitchens. They have every imaginable piece of equipment. A lot of my friends were triathletes so I was trying it out on them. I was just fascinated with how you could take a food like that in fairly condensed form and fill it with energy, with nutrients. 

NBJ: What goes through your head now when you look at so many feet of shelf space packed with energy bars?

Karnazes: The market is just so saturated. I think that bars are part of a larger problem. They have their place, but I think when you look at the calories in a lot of these bars, it's equal to a candy bar. People are eating them and thinking, 'Yeah, this is great energy.' The biggest trend I saw when I ran across America last year is clearly inactivity and obesity. We are taking in too many calories. Bars are part of that.

NBJ: As an athlete, what are you emphasizing in your nutrition plan right now?

Karnazes: I have changed my diet dramatically over the last 20 years. I have pretty much gone to a paleo diet, kind of using the filter of Neanderthal man. Could Neanderthals eat that food? That's how I choose. Could Neanderthal man eat anything with a processed grain, be it rice, oats, wheat? Anything that you can't just pick off a tree and put in your mouth, he wasn't able to eat.

I don't think our system has evolved to handle processed food and a lot of the grains that we are consuming. I found when I eliminated those, my performance got better. My energy level throughout the day got much more consistent. When I was doing the carbo-loading thing, I had the peaks, the troughs. Now my energy level is much more consistent. I pay attention to when I eat a certain food. How do I perform? How does it leave me feeling and how does it help me recover or not help my recovery? I filter out foods that hinder and add in foods that enhance.

NBJ: What have you added in recently?

Karnazes: I've gone to natural hydration. Plain coconut water is an incredible electrolyte. The thing with drinking Gatorade or some of the mixes is, if you mix it too concentrated, you go osmotic. If you're a runner, you get the trots. A lot of people are using coconut water. I just ran this 135-mile race across Death Valley, the Badwater, and I drank something like eight gallons of coconut water. If you had that much glucose coming into your system, you'd have all kinds of GI problems.

NBJ: How do you know when you've got it right?

Karnazes: It's a really complex formula because there are so many variables. It could be you didn't sleep well the night before. You're overtrained. You're undertrained. But you get a general trend line. I think it's less scientific and more of an art, the art of learning to tune into your body over years of doing these things. Certain foods just seem to work better than others. 

NBJ: This all sounds complicated. What do you tell casual athletes?

Karnazes: I always guide people—'listen to everyone, follow no one.' I think in nutrition we are all an experiment of one.

NBJ: What is the big mistake casual athletes make?

Karnazes: I think they are consuming too many calories. People who are not heavy aerobic athletes are consuming too many calories for their activity. My son is in high school, and they say you need a big thick protein shake after your workout. I'm telling him, 'Nick, there are 900 calories in that thing. You lifted weights for 45 minutes. You probably burned 300 or 400 calories.' I think people are taking in too many calories overall and way more protein than they need.

NBJ: Give us an example of when you got it completely wrong?

Karnazes: That primarily happens using products like Cytomax and Accelerade, and mixing the products from a powder and getting it too concentrated. Then it can blow right through you. It throws your electrolytes out of balance. It happened to me the first time I tried Badwater, and it's a death spiral. Once you throw your electrolytes out, you have diarrhea or vomiting. It's really hard to recover in a race, but it's not possible.

NBJ: In ultra-endurance sports, what is the trend of the moment?

Karnazes: There are a couple of things going on. There are these extremely high-molecular-weight carbohydrates, basically starches. The absorption rate is really, really slow so you don't really get a spike. You don't get an appreciable change in your blood sugar level. You also don't have as much GI distress. That's one of the trends.

The other trend is what they call shifting the substrate utilization, so when you are below your lactate threshold, you are getting more efficient at burning fat—being able to boost your aerobic capacity while still not utilizing your stored glycogen. Fat has nine calories per gram, so it's much more concentrated. Looking at different types of fat—monounsaturated, polyunsaturated, different types and blends of fats—to see what can give the most energy.

NBJ: That doesn't sound very paleo.

Karnazes: Well, there are nut butters. A caveman could access nuts. He could access legumes, nitrate fixators like a peanut. It wasn't dry roasted, but nut butters are pretty close to paleo. But that's just my diet. Different athletes are using different kinds of things.

NBJ: How do you evaluate a new sports nutrition product?

Karnazes: Is there science behind it? There is so much conflicting data you read every day. There's also so much that's market driven. You always need to look at who is financing this research. And some of it is blatant advertising that looks like legitimate studies by companies trying to push their products. So I think there is a lot of misinformation out there and a lot of bad information as well. People are still drawn to shortcuts.

NBJ: How do you keep up on nutrition science?

Karnazes: I am a prodigious reader. I read like crazy—journals, new books that come out. I am constantly scouring literature looking for new ideas, new trends. If something looks legitimate, I try it on myself. I always experiment on myself. Most of the mainstream media headlines are things athletes have heard for years. Typically it's something where my wife says, 'You've been saying that for the last three or four years.' I don't really see too much fresh stuff.

NBJ: It sounds like you're predicting the next big wave in sports as natural and organic with fewer sports-specific products.

Karnazes: I think it's going to be a trend toward more natural foods because you can eat more calories and not get the kind of GI distress you get with condensed and concentrated foods. Look at the ancient Greek marathoners. They were eating a paste that was sesame seeds mixed with honey. If you look at some of the things they were doing back then, their performances were incredible, and they didn't have any of the modern training techniques that we have now. 

NBJ: How do we change the way people eat in America?

Karnazes: It's going to take a wave of parents going through the health care system with all the problems until their kids realize, 'Hey, I can't be like Mom and Dad.' So many people come up to me and say, 'I am so worried about little Johnny. He doesn't eat well. He doesn't exercise. What do I do?' I look hard at the parent and say, 'Do you exercise? Do you eat well' Most of them don't. Let's face it, you influence your kids' behavior more than anything. Kids are quick to look through hypocrisy. So I think it's going to take a while to flush through things. When I travel the country, I notice a healthy band from Seattle coming down the West Coast, another sweeping up the east coast and Chicago is pretty healthy. The rest of the country is lagging behind.

For a status of the sports nutrition and weight loss market today, purchase the Sports Nutrition and Weight Loss issue from NBJ.