Dr. Jeff Volek is one of the leading "new school" researchers in the areas of nutrition, resistance training, lipid metabolism, and endocrinology. He also knows more about low-carb dieting than just about anyone else on the planet.

Greg McGlone recently cornered Dr. Volek and fired a few questions at him. Here's what he had to say!

Greg McGlone: Dr. Volek, why don't you introduce yourself to those in the T-Nation audience who don't know you?

Jeff Volek: I studied dietetics in college at Michigan State University. In retrospect, the coursework was a complete waste of time, but after four years of BS I earned a B.S.

I did an internship and received my R.D. (registered dietitian) a year later and worked for a year in a clinical setting. Knowing there must be more, I sought out graduate schools in exercise science with ambitions to be a strength coach with a masters degree and R.D. This led me to Penn State University where I was first exposed to research.

I loved it and was hooked. I couldn't soak up enough information, spending entire days in the library reading and absorbing as much as possible. It was during my thesis project (the first study investigating the effects of creatine supplementation on resistance training performance) that I had an epiphany. I realized who I was and what I wanted to be — a scientist. So I naturally continued on the academic path in the doctoral program.

GM: When did you become interested in low-carb diets?

JV: Beside creatine and sports nutrition, the other topic I was reading about late at night in the library was low-carbohydrate diets. By this time I'd abandoned everything I learned in dietetics and stopped the ultra low-fat approach I was doing in favor of a low-carbohydrate diet. My dissertation involved a prospective low-carbohydrate diet intervention aimed primarily at markers of cardiovascular disease.

After receiving my Ph.D., my first job as a professor was at Ball State University. Then I moved to Connecticut and I've been an assistant professor in the Human Performance Laboratory at the University of Connecticut since 2001. As a professor, I teach undergraduate and graduate courses in areas such as physiology, exercise physiology, sports nutrition, muscle physiology, and lipid metabolism.

My real passion is research and working with graduate students. I love going to work every day, interacting with my team, and making scientific discoveries.

Oh, and for what it's worth, I do lift so I'm not just an academic with no pragmatic sense of how to translate research for the guy in the gym. My stint in powerlifting lasted about five years, and despite less than optimal genetics I managed to collect a little hardware.

GM: You're an expert on the topic of low-carb diets, so what's your definition of low-carb anyway?

JV: There are no firm guidelines for a definition of low-carbohydrate diets, but I'll give you my opinion with some explanation.

The term "low-carbohydrate diet" is frequently identified with the Atkins diet. This leads to several problems in that the Atkins diet has four different levels of carbohydrate restriction and hence potentially very different composition, and it's an ad lib diet which is frequently accompanied by spontaneous caloric restriction.

On the other hand, prescribed diets (not ad lib) have at least four total and three independent degrees of freedom. To concisely capture this information, I'd suggest diets be described by their energy level and relative macronutrient distribution. For example, a study could compare isocaloric 2000 kcal diets that were either low in carbohydrate (% carb:fat:protein = ~9:29:62) or low in fat (~59:19:21).

In describing diets in narrative, I'd use as a starting point the NHANES data showing that carbohydrate consumption before the obesity epidemic was 43% of total energy. My suggestion is that any diet nominally less than that, say < 35-40%, be considered a "low-carbohydrate diet," although the caloric level if substantially different from 2000 kcal would have to be indicated.

The assumption of low-carbohydrate diets is that there's an inflection point, that is, a sharp break in metabolic effects. This point, as in the Atkins diet, is identified with ketosis. This is frequently used as an indicator of compliance with a carbohydrate restricted diet. Although the actual onset of ketosis varies among individuals, the rough range for the onset of ketosis is 50 grams a day, or on a nominal 2000 kcal diet, approximately 10%.

I'd recommend that diets that target this level of carbohydrate be referred to as low-carbohydrate ketogenic diets (VLCKD). The unmodified term ketogenic diet should be reserved for the very high fat diet used in the treatment of epilepsy. I'd note that this diet is fairly unpalatable and is, in my view, an anachronism.

Comparable results in treating seizures with the simpler VLCKD have been reported. I'd propose referring to diets in the range of 40-55% of calories as moderate carbohydrate dietsand anything greater than 55% as high carbohydrate diets, again with the caveat that the caloric level may change the actual impact of such diets.

GM: Should most people be adhering to low-carb nutrition, regardless of whether they want to gain mass or cut body fat?

JV: The majority of people will find it much easier to cut body fat with lower carbohydrates. There are many other reasons to restrict carbohydrate for metabolic health. Gaining mass may be achieved with high carbohydrate, but at the expense of compromising fat loss — and for most people, metabolic health.

GM: So you say most people gain mass at the expense of fat loss, which is usually understood, but what strategies would you suggest for those who might be in a mass gaining phase but want to be healthy and still look good naked year round?

JV: Building muscle and losing fat at optimal rates is a compatibility problem. It's the same concept as trying to train for maximal endurance and muscle strength performance at the same time. They're opposing physiological demands.

In the case of endurance training, the stimulus is to keep the cell size constant or even shrink it to maximize oxygen kinetics, whereas for strength training there's a stimulus to increase muscle cell size to overcome the overload demands.

Building muscle and losing fat requires an anabolic state in muscle and catabolic state in adipocytes, respectively. Most guys are willing to compromise though and aren't interested in one over the other.

The best compromise to achieve some muscle growth while still allowing very significant fat loss and therefore "still look good naked year round" is to follow a low-carbohydrate diet or even a VLCK diet, and of course hit the weights. You can augment the muscle growth further without compromising fat loss by supplementing with creatine and using appropriate pre and post-workout nutrition.

GM: You said by focusing on pre/during/post-workout nutrition and low-carbing it the rest of the time, someone could see modest muscle gains while experiencing significant fat loss. Do you think that the idea of cutting and bulking is outdated, and that perhaps body recomposition is a more realistic goal to chase? Or would it be too much of the whole "If you chase two rabbits, both will escape."

JV: Historically, bulking and cutting was the primary method used to get in contest shape for bodybuilding. I'm not sure we should totally relegate this approach to archival status, but it's worth exploring other options.

To be frank, I've never come across a lot of scientific evidence for this approach, but I've been to enough bodybuilding shows to know it does work quite effectively for some people, but it's hard to separate out the effects of pharmaceutical assistance in many cases.

More to the point, the downside of this approach for the average guy is that you have to go through a bulking period where you build a solid foundation of muscle while basically getting fat. Many guys would prefer not to go through this phase because they only look good for a short time when they peak.

The major advantage of creating a nutrient partitioning effect is that you steadily lose fat and build muscle and therefore create a more permanent "in shape" physique that can be sustained.

GM: What supplements do you find to be useful for fat loss and for following a low-carb diet in general?

JV: The beauty of the low-carb diet is that there's little else you need to do to augment fat loss further. By reducing insulin, lipolysis is increased markedly and your energy needs are being met almost exclusively by lipid fuel sources (fatty acid and ketones).

If you consume adequate calories, the lipid fuel is mainly from exogenous (diet) sources, but if you cut calories, energy comes from endogenous (body fat) sources. The real trick is to prevent the muscle loss and ideally build muscle.

My first two supplement recommendations would therefore be protein and creatine. It's critical to get a high quality protein source (like whey) before and after workouts. Including extra branched chain amino acids rich in leucine would be ideal because in addition to its structural role in proteins, leucine directly acts as a nutrient regulator engaging cell signaling pathways that leads to protein synthesis. This is a very efficient way to augment protein synthesis without providing a lot of calories.

You can throw in a few carbs to increase insulin, which acts in synergy with the effects of amino acids to increase protein synthesis, and this hormone may also inhibit protein breakdown. But you don't need to go overboard because research shows large increases in insulin don't stimulate protein synthesis further. This way you keep the negative effects of insulin on lipid metabolism under control.

Beyond protein and creatine, there are a multitude of health benefits associated with omega 3s (EPA and DHA). I also like vitamin E supplements (gamma as opposed to the more common alpha form) for its anti-inflammatory effects.

GM: Okay, now let's talk about training, both weights and cardio. What are your thoughts on what works, what doesn't, and how low-carb nutrition can give you superior results on both fronts? For the sake of simplicity, let's say we're dealing with someone who's training for aesthetic reasons, but also wants to be able to lift more than a wet paper bag.

JV: If your main goal is to look good and maintain decent strength levels, training should definitely be focused on resistance exercise to build muscle, and adjust diet (i.e. lower carbs) to burn fat. I don't see endurance training as that important, unless of course you feel the need to increase your maximal oxygen consumption or you just enjoy it.

In regards to what works with resistance training, I'm a former powerlifter so my bias has always been on lifting heavy weights in core exercises with long rest periods. I found this very motivating compared to bodybuilding type workouts that involved higher volume training with short rest periods. Having endured this type of training over the years, I can say it takes it toll on your body, and I have my share of aches, pains, and nagging injuries.

In retrospect, I wish I would've periodized my workouts more and focused on more assistance exercises to balance my strength out and allow for more recovery. People may be looking for that magic program, but I can't emphasize enough the complexity of scientific training. There's much more we don't know than what we do know.

I still believe there's nothing better than a hard squat workout to create an anabolic stimulus, but again this has to be done judiciously and in the context of some larger periodized plan that allows for periods of lighter training.

On diet, I can say low-carbing it while training for powerlifting was very easy and effective for keeping lean. I rarely performed over six reps and so even though my glycogen stores may have been reduced, that type of exercise isn't taxing on glycolysis and acid base stress, so I never felt this was a hindrance.

GM: Tell us a bit about your most current research. You were recently given a fair amount of money by the Atkins Foundation. What are some new things on the low-carb front?

JV: Low-carb has been my major line of research for the last ten years. Low-carbohydrate diets have been very misunderstood by most people and professional organizations. My research has focused more on clinical implications than exercise, although we have begun a study examining interactions of diet and training.

We do have a big problem with obesity in the U.S. and so this has driven my interest in areas specifically related to management of obesity, metabolic syndrome, and heart disease. The fact of the matter is that current leadership under the ADA, AHA, etc. has failed to prevent and is currently unable to curtail the epidemic of obesity and diabetes.

Rather than explore all possibilities that might help, they're specifically trying to reduce the options for diabetic patients even though their own publications admit that reduced carbohydrate improves glycemic control. Rather than trying to find anything positive that could be used from the numerous publications on low-carbohydrate, they ignore almost all of them and have a blanket condemnation.

I could go on and on surrounding the mythologies of low-carbohydrate diets, but suffice it to say reducing carbohydrates is a very healthy approach and the preferred method to treat obesity and metabolic syndrome. Reducing carbohydrates is far better than any drug to treat diabetes; it's like taking a hammer to the problem whereas other lifestyle and pharmaceutical interventions have minimal impact.

Perhaps one of the most important discoveries is that carbohydrate restriction has an underlying mechanism — fat is relatively passive and insulin controls the disposition of fat. Given the intimate connection between carbohydrates and insulin, you can see the focus has been on the wrong nutrient.

You are not what you eat; you are what you do with what you eat. Eat fat with carbs you get fat, but eat fat with low-carbs and you get lean — and insulin is the switch that controls the fate of fat.

GM: In terms of carb tolerance and insulin sensitivity, how do you feel about the subject of the leaner one gets, the more carbs he or she can start to add back into his diet without worrying about fat gaining/regaining?

JV: I think you're right on. The reason you should start thinking about reducing carbs in the first place is that you want to lose body fat or you have metabolic problems associated with insulin resistance. If you're already ripped and have a high degree of insulin sensitivity you'll be able to tolerate more carbs.

I'd emphasize that there's a lot of heterogeneity among people in terms of how they respond to carbohydrates. Each person probably needs to dial in to their ideal carb intake that works for them at any given time. The point is to start thinking about carbs more than dietary fat as opposed to the other way around.

Basic biochemistry and metabolism would predict that carbs have a dominate effect on metabolism due to the close connection with insulin. Building on this notion, our research points to the idea that dietary fat plays a relatively passive role, and detrimental effects of fat will generally be seen only in the presence of high carbohydrate which, via insulin, determines the metabolic fate of ingested fat.

Again, in the real world, some people will need to restrict carbs more than others to kick into fat burning mode, and others will be able to tolerate more carbs without observing adverse effects.

GM: Are there some guidelines in terms of current levels of body fat and how many carbs — percentage or just straight up grams — that you could give us?

JV: Be wary of anyone who claims to have a magic formula for prescribing the precise amount of carbs... or any other nutrient for than matter. There's far too much variability to make these types of absolute recommendations. This is the foundation of personalized nutrition and in the bigger picture personalized health (the antithesis of public health).

We have the technology to measure a person's entire genome in a single blood sample and use that information to predict how they respond to various dietary interventions. We've done this in our studies and have made progress in understanding the genetic factors that contribute to variable responses to low-carbohydrate diets in weight loss, fat loss, and other health markers.

For now, most people won't have access to genetic testing and so the best advice I can give is to become an experimentalist. There are many ways to restrict carbohydrate, and you have to experiment with different approaches and monitor the results — just like a scientist would do in the lab. In the end, it doesn't matter what the science or the experts say; you should do what works best for you.

Most guys do much better on low-carb. So I think a logical default approach is to take your current level of carbohydrate intake and reduce it. A minimum of 20-30 gram reduction would be a good place to start and see what happens. Give it at least a couple weeks and if you don't detect a positive effect then reduce the carbs another 20-30 grams.

Others may prefer to go cold turkey and remove most of the carbs from their diet. There are no hard rules here other than to do experiments, observe your results, and make appropriate decisions based on those observations. The only way you can fail is to keep doing the same thing and not give different approaches a try.

GM: Cool. What's on the horizon for you project-wise?

JV: Adam Campbell and I are nearly finished with a book that we've been working on for quite awhile called the TNT Diet. For this book, we asked the question: what innovative tactics can be utilized to optimally enhance body composition? More specifically, what sensible procedures can be utilized to simultaneously build muscle and lose fat?

It's a program based on scientific research that shows men how to use Targeted Nutrient Tactics (TNT) to trade their fat for muscle. The philosophy of the book is heavily based in science and basic physiology, which unfortunately hasn't been part of mainstream diet recommendations.

One basic concept of human survival is the ability to maintain homeostasis or balance. For example, when you're cold you begin to shiver to increase temperature back to normal. A more relevant example might be when you restrict calories, your metabolism decreases to maintain energy balance. You see, in this case, homeostasis can work against you if weight loss is your goal.

We take advantage of the body's homeostatic responses that occur as a result of eating diets varying in composition to stimulate metabolic pathways to enhance body composition. Rather than promote moderation like most nutritionists, we put an emphasis on extremes in nutrient composition that cause the body to adapt in a more robust manner to maintain homeostasis.

What often occurs is that the body overshoots, and if the diet is manipulated in a synchronized and coordinated manner, you can exploit this phenomena to your advantage to achieve simultaneous muscle gain and fat loss. What we show is how you can effectively partition nutrients, that is, divert the calories consumed away from storage in fat cells and redirect them toward muscle tissue where they'll be used in anabolic processes.

On the research end, my plate is always full, but I'm always hungry so we're pushing a lot of different lines of research. We have some controlled feeding studies planned in both animals and humans where we'll be investigating the role of fat quality in a low-carbohydrate diet and the impact on a wide array of metabolic and cardiovascular markers.

We're continuing to refine our knowledge on ways to optimize the effects of low-carbohydrate diets through the interaction of resistance training and other dietary supplements. We're also pursuing some work on novel whey peptides that affect vascular function and the underlying biological mechanisms and how they contribute to optimal adaptations to resistance training.

GM: Sounds exciting, Dr. Volek. Any final words?

JV: I know there are a lot of guys out there who want to trade fat for muscle and look, feel, and perform better. If you're frustrated with your current progress, I highly recommend giving a low-carbohydrate diet a try.

In our most recent study we've seen several guys lose more than 20 pounds of fat and gain as much as 12 pounds of muscle in a 12 week period. The combination of carb restriction and periodized resistance training is potent. Using these two approaches as a foundation, you can begin to experiment with all sorts of modified versions to find the approach most suitable for you.

The body has a tremendous capacity to adapt to its environment, so provide the right stimuli and I can assure you that you can improve your body and your health.

GM: Interesting stuff, Jeff. Thanks for the interview!