The Ben Moore has asked me to give my take on Low Carb diets. I will say upfront that I am biased toward low carb diets and really think they are a healthy way for the vast majority of people to eat. So, be prepared for an article totally spun in the direction of my view. If you disagree feel free to voice your opinion as there are some important aspects of low carb diets that may not be totally illuminated in research as of yet. I also hate Jared from Subway.
My appreciation for low carb diets dates back several years but recently was rejuvenated by a conference I attended at KU. There was a group of three presenters who all gave different aspects of low carb diets; one related to clinical populations (predominantly female), one was a historical perspective with some performance points, and the last one was almost entirely performance and body composition related. I will spend the most of the article discussing the latter two and related material, with a very brief overview of the clinical talk.
The clinical talk was given by a bariatric MD in Lawrence, KS who has had great success prescribing low carb diets to her female patients. Most of the patients she described were post-menopausal women who were overweight and inactive. Most of them were pre-diabetic and consumed what I would call an average American diet; heavy on carbs, with moderate amounts of fat and protein. All of her patients returned their diabetic and cardiovascular health markers to normal ranges within a matter of months on low carb diets. That is about all there was to it.
Way back yonder about one hundo years ago turn of the 20th century an anthropologist by the name of Stefansson went off to live and study the lifestyle of Inuits. One of his biggest surprises was the diet; meat only. The primary meat source was fish (whatever they caught), with some caribou (Santa’s reindeer), the occasional polar bear, and birds. The meat was eaten raw or boiled. Edible organs and bone marrow were also consumed. Once the meat was finished they drank the water it was boiled in, as there were vital minerals in there, and they also wasted as little as possible. This came out to be about 15-20% protein, right around 80% fats, and less than 2% carbohydrates. These Inuits lived perfectly healthy lives and rarely became ill. They did not have a tremendous lifespan however. Stefansson equated the lower life expectancy to the drastic temperature changes and the overall cruel climate in which they lived.
Stefansson went on the live with the Inuits for about 5 years non-consecutively and catalogued all his observations throughout. His early observations about feeling fatigued for the first two weeks of being with the Inuits still stands true in research today. After those 2 weeks, the feelings subsided and Stefansson never felt healthier. He stated the he rarely, if ever, got ill after converting to a primarily meat diet. The Inuits are also nomadic and very active. They did not have the means to overeat, but when they had a lot of meat, they ate it all. So, he goes back to the states and begins a lecture tour of sorts and publishing papers on his findings. Even though he lived through it, no one believes it is possible. The common view then, much as it is now (way to change America), is that the less meat the healthier you would be. Your arteries would be strong and elastic, your blood pressure lower, your kidneys would shut down, you would not live as long, and without veggies you would develop scurvy. Stefansson even made the fantastic old timey statement that he would be considered a “charlatan” for his meat only views. In order to let everyone witness first hand the success of a meat diet Stefansson agrees to a year long study through Bellevue Mental hospital under strict supervision of researchers, PhDs, and MDs. Throughout the entire year he remained alive and healthy, with the exception of the first few weeks. During those first few weeks one of the study overseers wished to place Stefansson on an extremely lean meat diet. Stefansson started feeling ill and lost his energy, upon switching back to less lean meat his healthy bounced back and he did not have another incident. His disease risk markers did not change. Despite all the modern knowledge of a balanced diet and the so said necessity of vegetables, a human being can live a very healthy life on meat alone.
Another quick note on Stefansson’s conclusions; in his article he appears to loathe the dentistry practice. He makes a statement to the effect that the Inuits do not have brushes, powders, pastes, and do not gargle on a daily basis, but not a single one of them has tooth decay. He goes on to state that in his research of early civilizations that relied heavily on meat, he found absolutely no evidence of tooth decay across hundreds of years.
Main points of Stefansson:
-Eating meat and being active is a healthy way to live
-Animal fats are probably the single most important nutrient to consume
-It takes about 2 weeks to adapt to a low carb diet
-Dental care is overrated when consuming predominantly meats, at least in the early 1900s dentistry practices
Now, the Stefansson work is an extreme example that humans can obviously survive on, but presently there are a lot of tasty and generally healthy food options in the land of carbohydrates. Not to mention that key times of carb ingestion can be a potent anabolic stimulator.
From a performance standpoint, low-carb diets are just as good, if not better for endurance type athletes. Relying more heavily on fat gives them more energy to draw from within their body. One study I read showed cyclists increased their riding times significantly, did not rely on CHO nearly as much, and had lower inflammation markers on low CHO diets. However, there was not as much (read as: none) evidence for high power, anaerobic athletes. No significant differences in power outputs or strength measurements between low carb and normal diets. Low carb diets do consistently show decreases in body fat, blood lipid profile improvement (decrease LDL and increase/maintain HDL), increases in lean mass, and sometimes decreases in blood pressure. So, if blood lipid profiles, fasted blood sugar, oral glucose tolerance, and markers of inflammation all stay at healthy levels on low carb diets and there is no decrease in performance why would a power athlete think it is a bad idea? Especially in SM/PL where guys brag about how much they eat and how little cardio they do. I have also read studies showing that increases in red meat consumption did not affect blood lipid profiles and low meat consumption group had slight negative changes in blood lipid profiles.
Should come as no surprise that the blood markers I mentioned above are what become chronically elevated following a typical American diet. Those increases also show an incredible correlation with the "low fat craze" that came about in the 80s and 90s that more or less flooded the food world with high carb, high processed garbage that we are finally seeing the negative effects on children who were raised on it, myself included. Thanks Jared from Subway, you skinny fat bastard. Another strike against Jared; a study investigating low fat/high carb diet showed a 60% increase in triglycerides, 37% decrease in VLDL-TG clearance (which is a marker of inflammation), and an 18% reduction in whole-body fat oxidation. So, your lipid profile gets slightly worse, you are more inflamed and burning less fat. Awesome. Perfect explanation for why Jared looks the way he does.
You may be a legitimate strength and power athlete and not just some fat bastard gym hero who never competes; you may be worried about glycogen depletion detracting from you workouts and possibly your competition performance. I do not think you need to worry. Low carb diets will typically be around 10% CHO in a research setting. In a study by Volek, they found a decrease in fat mass and an increase in lean mass with that 10% CHO diet. I did come across a high intensity exercise study with carb restriction in relation to glycogen depletion. It was in cycling athletes and found a decrease in performance across 5 min when muscle glycogen is depleted. However, the muscle glycogen was depleted over 1h-1.5h of exhaustive cycling and then followed by 3-4 days of less than 5% dietary consumption of CHO. For those of you who are not mathemagicians, that is half the amount of carbs that were given to study participants who lost fat and gained muscle in the previous study. Exhaustive cycling is not the exact same as strongman or powerlifting training, but I am willing to bet most of us do not come close to the amount of volume required to deplete our muscle glycogen stores during our daily workouts. I do not remember the exact numbers but, Lyle MacDonald in his body recomposition diet programs glycogen depletion workouts. One of my close friends did this for a time and his glycogen depletion workouts were pretty intense and high volume (upwards of 10 sets of 10). Also, many nutrition experts like MacDonald, Mauro DiPasquale, Shelby Starnes, Justin Harris, etc. do have carb-up days where, if you had the muscular fitness and desire to deplete your glycogen, those stores would be replenished. Most definitely you would have a carb up meal(s) before your competition as well. Who doesn’t love post weigh-in feasts at IHOP?
One of the main talking points of Jared from Subway clones is renal toxicity. High protein diets will invariably shut down the kidneys and send them screaming out your ass demanding you start eating more Cinnamon Toast Crunch and making daily stops at Wendy’s for a Frosty. In the Volek study there was only one small paragraph in the discussion related to renal stress. One marker of renal stress was increased but not another, and not significantly enough to demonstrate renal stress due to increased protein catabolism. The protein catabolism was also assumed to be coming from dietary protein as nitrogen retention was increased and the obvious gain in lean mass would negate muscular protein being the source of this protein catabolism.
As far as my diet recommendations go, I obviously favor low carb. I would keep in some veggies and specific carb supplements at proper times. Pre and post workout are excellent times to take in carbs like waxy maize, simple sugars, and other carb products that quality supplement companies put out. I would also allow room in your meals for more quality complex carbs like sweet potatoes...love me some sweet potatoes. You would probably want to limit large simultaneous amounts of carb and fat consumption, as one of insulin’s actions is to halt fatty acid oxidation. Obviously you should consume protein with every meal and/or snack. Another tid-bit I picked up recently on Shelby Starnes’ training journal is about fiber, no point in paraphrasing so here is the link
< http://asp.elitefts.com/qa/training-logs.asp?qid=99788&tid=163>
Something that bears repeating is fat intake. If you are eating animal flesh, not a big worry, you should be getting adequate amounts of it. It makes a lot of sense that way back at the beginning of the article I mentioned Stefansson getting ill when eating extremely lean meat. Fat and cholesterol play many important roles in our daily health. Most importantly, testosterone is a cholesterol based hormone. So you need cholesterol for testosterone production. Testosterone also has an incredibly positive effect on immune function, just ask an AIDS patient who is supplementing (thanks Chris Bell and “Bigger, Faster, Stronger*”). An additional point can be made for the newest craze in personal health; adequate Vitamin D intake. Vitamin D just happens to be a fat soluble vitamin. Looks like fat is some pretty awesome stuff. This next one should go without saying; stay active. If you think you are active enough, you aren’t, you are a strength athlete who is not an international competitor and looks like the Michelin man. You can afford to cut some fat and still compete at the regional level. I say that to myself everyday, but I’m also a little guy, you big guys should take that to heart a little more often.
