Research On Low Carb Diets
By Carlon Colker, M.D., F.A.C.N. Flex
So many people still ask me that question. For those scratching their heads in disbelief, as FLEX magazine’s Chief Medical Muscle Monger, I’ve been saying for years that low-carbohydrate diets most certainly do not dull your anabolic response to weight training. Now we’ve got the science to prove it.
First of, carbohydrates are sugars. They have traditionally been viewed as the fuel for most body functions. Over the years
this misperception has been thoroughly reinforced by everyone, from sport drink marketers who say you have to constantly suck down their sugar swill just to get your bony ass of the bench; to misguided school-lunch dietitians who, for years, made carbs a staple of crappy school lunches and thus to the chubby-child epidemic; to even the federal government, whose old Food Guide Pyramid with its moronic message of recommending 6–11 servings of carbohydrates daily created generations of type-2 diabetics.
In truth, your body can make all the carbohydrates it needs in the form of glucose from the fat and protein you take in. Your body requires no orally ingested carbohydrates for this function. This is a medical fact that countless professional and non-professionals continually ignore. Perhaps this misperceived “need” for orally ingested carbohydrates comes from the fact that at the cellular level the body certainly does require glucose for energy (the simplest form of the carbohydrate sugar molecule). But that doesn’t mean you have to EAT IT!
Glucose marks the beginning of the energy utilizing pathway known as glycolysis, which yields a molecule called adenosine triphosphate, or ATP. ATP is the true currency of energy in the human body. Every cell in your body runs on a steady supply of it to function. Without ATP, nothing happens. This is especially true for muscular contraction. When you are working out hard and your muscles are pumped, ATP is consumed. Since this energy cycle begins with a molecule of glucose, it comes as no surprise that carbohydrates have mistakenly become the star of the show in terms of the traditional scientific and textbook definitions of our dietary source of energy. The truth is that dietary fat is a far more efficient feeder of this pathway of energy production, but not if your body is too used to carbohydrate ingestion. The longer you have ignored and bypassed this path, the more atrophied and inefficient it becomes. The body can become so used to an unnatural steady sugar intake that our physiology can “forget” about the dusty path of using dietary fat for energy. Still need more convincing? Well, just look at the state of our health as a society ravaged by the toxic effect of a sustained elevation of insulin in response to the steady stream of carbohydrates being fed to us. The result is epidemic obesity and diabetes (obesity being the leading risk factor for type-2 diabetes).
THE ONLY REASON DIETARY CARBOHYDRATES HAVE BECOME SO IMPORTANT IS BECAUSE SOCIETY, NOT THE LATEST SCIENCE AND OUR OWN PREREQUISITE KNOWLEDGE, HAS MADE IT SO.
Although orally ingested carbohydrates have classically been touted as the major fuel source of human energy, this could not be further from the truth as to how our body should be working when we are treating it properly. Bodybuilders know that, yet some of the vast misperceptions of the rest of humanity still seem to seep their way into the minds of my brethren in iron. These imbeciles make us doubt ourselves and start cracking open the pre-workout carbohydrate drinks as we convince ourselves that without this poison we’ll lose muscle. To them I say we must remind ourselves that the only reason dietary carbohydrates have become so important is because society, not the latest science and our own prerequisite knowledge, has made it so. Remember that orally ingested carbohydrates are not “essential,” because your body can make all the cellular sugar it needs from the fat and protein you ingest. Protein, on the other hand, is absolutely essential. Without eating certain essential amino acids you can’t efficiently build muscle. While some fats are harmful, certain fats—
like essential fatty acids—are critical and must not be neglected in the diet. It is only carbohydrates that have no essential character. Good bodybuilders have known that dietary carbohydrates were the problem all along. It’s just the rest of the world that still needs to catch up.
Of course, for those bodybuilders that are still stuck in the dark ages or have been sucked back into the misguided perceptions that they need a big carbohydrate bolus otherwise muscle disappears, finally the published medical research has caught up and proven that low-carbohydrate intake does not reduce the amount of muscle you have in response to training. Specifically a study performed by the School of Medical Sciences, RMIT University, in Melbourne, Australia, determined the effect of muscle glycogen concentration on muscle growth after weight training. Muscle biopsies confirmed glycogen concentration was higher in the control group verses the low-glycogen group at all times, yet they showed that commencing high-intensity exercise with low muscle glycogen did not compromise the anabolic signal and/or performance results.
Perhaps even more shocking, and most certainly not what the rest of the world is ready to comprehend, these facts also hold true for endurance athletes as well. But even more surprisingly, their performance may even benefit from reducing dietary carbohydrates and relying on structured amino acid solutions and healthy fats instead! In fact, it’s now been shown that endurance athletes increase the maximal activities of several oxidative enzymes that promote endurance to a greater extent when they have lower glycogen levels. So much for carbohydrate-loading with that big pasta dinner before
the race or squeezing that sugar goop at the halfway point of your road race. Furthermore it has also been credibly demonstrated through muscle biopsy study that skeletal muscle responses to high-intensity endurance training result in molecular muscular signaling that remains unchanged despite lower muscle glycogen. These results may amaze some, confuse others, and down-right piss of many athletes, trainers, coaches, and nutrition gurus that thought they had it right all along and stuck to these older dogmas with religious fervor.
LOW CARBOHYDRATE DOES
NOT MEAN NO CARBOHYDRATE
Of course that doesn’t mean that I’m advocating a zero-carbohydrate diet for bodybuilders or any other athletes. Keep
in mind that “low carbohydrate” does not mean “no carbohydrate.” But rather than carbohydrate-based foods, I tend to favor fiber-based foods like vegetables and some fruits that happen to have what I call “incidental” carbohydrates, because the amount of sugar is relatively low. Fiber is crucial for good health and a strong body.
There are basically two types of fibers: soluble and insoluble. Soluble fibers like those in oatmeal are able to dissolve in water and become gummy, or viscous. Soluble fibers help lower blood cholesterol levels and help regulate the body’s use of sugars. So some small amount of soluble fiber is a good thing in the diet, even though a few carbohydrates come along with it. For the bodybuilder looking to gain lean mass while keeping body fat down, insoluble fiber like that found in salad roughage is particularly beneficial.
In addition to being loaded with naturally occurring minerals, trace minerals, and ultra-trace minerals, insoluble fiber foods are also powerful cancer-fighting anticarcinogens and digestive aids. Because “high-protein, low-carbohydrate” diets tend to cause constipation, adding this type of fiber is
also critical for regular bowel movements. Another nice thing about insoluble fiber is, unlike soluble fiber, it is not calorie-dense. Therefore you can and should have relatively large helpings of insoluble fiber. Veggies like lettuce, kale, cabbage, collard greens, celery, peppers, spinach, squash, onions, cucumber, asparagus, green beans, snap peas, Brussels sprouts, alfalfa sprouts, etc., are just some examples of healthy fiber-based choices and should be a significant part of any athlete’s diet, not just a bodybuilder’s.
Finally, I know I’m still going to hear a landslide of objections from die-hard proponents of a moderate- to high-carbohydrate diet for muscle building. The legions of detractors would point to the fact that insulin is, by itself, an anabolic hormone. But while this is true, high insulin levels are dangerous because it creates insulin resistance and diabetes. In addition, excess levels turn on lipogenesis (the process of making fat in the body) in order to dump the high-sugar loads out of the bloodstream.
What they didn’t realize back then was that we can get the benefits of insulin without using carbohydrates. The fact is that arginine, alanine, and the branched-chain amino acids (isoleucine, leucine, and valine), as well as glutamine found in whey protein are reasonably insulin-producing or “insulinogenic” without adding excess sugar calories. In addition, the insulin response to these amino acid proteins is far different and far better than the insulin response to sugar. Insulinogenic amino acids produce a much softer and more physiologic rise in insulin, in sharp contrast to the high insulin spike seen in response to the “toxic” presence of excess carbohydrate. This vigorous insulin response to sugar is an unnatural reflexive dumping pathway by which your body purges itself of what the physiology interprets as somewhat of a poison (i.e., too much blood sugar). Do it too many times and the body shuts down and you end up resistant to any effect insulin might have to either bring down blood sugar or stimulate muscle growth. As long as you are eating plenty of high-quality protein, you don’t have worry about losing out on the anabolic benefits a small amount of insulin might provide. Your body will still produce an ample supply if it needs to, just not an excessive supply in reactive response to a high blood sugar.
So, carbohydrates are in no way essential to the diet, be it for general health or for gaining muscle mass. So train hard, eat smart, and grow big!
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