12/10 Myth Busting Monday

A few Monday's ago I invited Ridgeline Fuels to write a guest blog on a nutrition myth. I had no idea the post was going to be about the Keto diet. I decided to publish the post knowing that some of our True Spirit CrossFitters are on the Keto diet and might have something to day. Well, they certainly did have something to say and I'm so glad they did! I heard from several of our Keto CrossFitters including John Elwell who wrote this elegant rebuttal to the Ridgeline post. I always appreciate a well though out position and critical thinking and that's exactly what John shares with us today. Enjoy!

The Ketogenic Diet
​By Guest Blogger John Elwell

The ketogenic diet (keto) is getting a lot of attention these days. Depending on who you’re listening to, a ketogenic diet will either help you lose weight and enhance physical performance, or it will give you a heart attack by tomorrow morning. So just what is ketosis?
Ketosis is simply the condition where the human body is using fat for energy. The liver uses fat to create ketones, which circulate in the blood to provide energy to the body’s cells.
You can get into a state of ketosis by simply reducing your carbohydrate intake far enough that the carbohydrates consumed cannot meet your body’s energy needs. Your body will then naturally start using fat for energy, and you’ll be in ketosis. That’s why our bodies store fat in the first place – as an energy source.
Ketosis is not an abnormal nutritional state, it is part of our bodies’ evolutionary survival equipment. No food available? Use stored body fat to stay alive. Evolutionary biologists even argue about whether ketosis might be the default state for humans.[1],[2],[3]
Most people are ketogenic (using fat for energy) when roughly 10% or less of their calories come from carbohydrates, but this varies person-to-person (and over time) in the range of about 5-15% of calories. And ketosis is not an on-or-off thing; it ranges from mild to full-on ketosis.
There is no such thing as the ketogenic diet. Ketosis is achieved by low carbohydrate consumption, but there are many ways to do that. Much of the debate about the ketogenic diet comes about because people approach it so many different ways. Eating nothing but bacon will put you into ketosis, but that may not be the healthiest choice. (But hey… if you’re going to ruin your health with bad dietary choices… what a way to go.)
Hopefully you’re eating a CrossFit recommended diet of whole foods, including meats & vegetables, eggs, healthy fats, some nuts, little fruit, and no grains or sugar, which is very similar to a Paleo/Primal diet. It is only a short step from any of these to a ketogenic diet: reduce or eliminate starchy vegetables such as potatoes and rice. A keto diet based on these foods, including plenty of vegetables, can be healthy, well balanced, and nutritious.
But you may have heard otherwise. Some comments I’ve heard lately:
Keto will give you a deficiency in Vitamin C. Not if you eat your veggies like your mom told you to. For example, a single bell pepper[4] has well over the daily recommendation for vitamin C[5].
Keto is deficient in fiber. Artichokes, broccoli, turnup greens, brussel sprouts, carrots[6] - vegetables are one of the most important sources of fiber in most people’s diets, and non-starchy vegetables are fine on a ketogenic diet. (Over 80% of the carbohydrates in kale are fiber – enough fiber you could probably make fence posts out of the stuff. Which is sort of what it tastes like anyway.) I eat more vegetables in paleo and keto modes than I ever ate on low-fat diets.
Keto restricts food choices. Unless you think that all available food is healthy in any quantity, then of course there are restrictions - any healthy diet restricts food choices. We evolved to live in scarcity – our bodies are very good at making the most of any stray calories lying around. But we are fortunate to live in abundance – we have to make choices.
The main things off the menu for maintaining ketosis are high-carbohydrate foods, but these are largely the wheat and sugar based, low nutrient-density, manufactured foods we should be avoiding anyway. Also off the table are legumes in large quantity, though as a condiment they are fine: a celery stick loaded with a tablespoon of hummus is about 8 grams of carbs, well within what you can eat and stay in ketosis.
Some of the tastiest foods that low-fat diets eliminate are back on the table in a ketogenic diet: bacon; cheese and cream (if you tolerate dairy); any kind of animal fat such as lard or tallow. Did I mention bacon?
Keto is unsustainable. I think this comes down to a mindset. If we spend time on any diet (keto, paleo, vegan, etc.) lamenting what we can’t have, we’re setting ourselves up for failure. But if our mindset is that we’re choosing not to eat some things (e.g. wheat, sugar) because they are bad for us, then it becomes more like avoiding smoking – we’re not as tempted because we know it’s bad for our health. Many people like myself have no problem staying ketogenic for months or years.
And there is no particular reason that you have to stay ketogenic if you try a keto diet. I cycle in and out of ketosis. Most of the time I’m in mild ketosis; if I go crazy with sweet potato casserole some evening, I’ll drop out of ketosis for about day. But my metabolic machinery is flexible enough that it makes no difference to my energy levels or stamina if I’m in ketosis or not.
Keto changes blood cholesterol levels.  Ketosis does seem to affect blood cholesterol levels. Often HDL increases and triglycerides decrease, but LDL also increases. The total/HDL ratio often improves. The overall cholesterol picture is complicated, and involves HDL, LDL, VLDL, IDL, triglycerides, etc., and different measures such as LDL-C and LDL-P.[7],[8] This is an area of active research today. Given the health benefits I’ve experienced by staying low carb/ketogenic, I lose no sleep over this.
Keto is no more effective than low fat diets for losing weight & maintaining the loss. Our bodies processes carbs and fat differently. Carbohydrates cause our blood insulin levels to fluctuate, whereas protein and fat do not. This fundamental difference makes losing weight on a high fat/low carb diet easier than on a high carb/low fat diet. Most people who try keto find it is easier to lose weight, with significantly fewer cravings and hunger pains, than with a low-fat approach.[9],[10]  And if we lose weight we want to keep it off - ketogenic diets appear to be better than low-fat diets at long-term maintenance of weight loss as well.[11]
Athletic Performance. Studies of athletic performance while ketogenic go back decades[12],[13], and recent studies[14] have confirmed the earlier results: if properly adapted to the ketogenic state, there is no difference in performance for endurance athletes. The key here is properly adapted. Our bodies adapt to dietary changes, but it takes time. If you jump into a multi-hour workout after having been keto for 3 days, your body is not going to be happy, and your performance is likely going to suffer. That is simply not enough time to adapt to a different primary fuel source, especially if you’ve been eating low fat for years.
But if you give your body time (some studies used 4-6 weeks) to adapt to fat as its primary fuel source (rather than carbohydrates), athletic performance can be maintained on a ketogenic diet. For extremely long events (12 hours and longer), some athletes are claiming significant improvements from having two fuels sources (fat and carbohydrates), rather than just one[15].
A well-balanced approach to ketogenic dieting can be a life changing experience.[16] If you’re interested in seeing if it works for you, I recommend starting with The Keto Reset Diet[17] by Mark Sisson. He offers balanced, thoughtful, and well researched advice on approaching the ketogenic diet.
References 
[1] Strohle, A., “Diets of modern hunter-gatherer….”, Nutrition Research, doi: 10.1016/j.nutres.2011.05.003.
[2] Lagakos, W., Ketosis in an evolutionary context. https:// http://caloriesproper.com/ketosis-in-an-evolutionary-context/. Accessed 2018.11.14.
[3] Masterjohn, C., Inuit Genetics. https://chrismasterjohnphd.com/2017/10/26/inuit-genetics-show-us-evolution-not-want-us-constant-ketosis-mwm-2-37/.
[4] https://ndb.nal.usda.gov/ndb/search/list.
[5] https://ods.od.nih.gov/Health_Information/Dietary_Reference_Intakes.aspx.
[6] https://ndb.nal.usda.gov/ndb/search/list.
[7] Schwingshackl, L., “Comparison of Effects of Long-Term Low-Fat vs High-Fat Diets on Blood Lipid Levels in Overweight or Obese Patients: A Systematic Review and Meta-Analysis”. J Ac of Nutrition and Dietetics, Dec 2013, doi.org/10.1016/j.jand.2013.07.010.
[8] Brinkworth, G., “Long-term effects of a very-low-carbohydrate weight loss diet compared with an isocoloric low-fat diet after 12 mon.” Am J Clin Nutr 2009; 90:23–32.
[9] Paoli, A., “Ketosis, ketogenic diet and food intake control: a complex relationship." Frontiers in Psychology, doi: 10.3389/fpsyg.2015.00027.
[10] Sumithran, P., “Ketosis and appetite-mediating nutrients and hormones after weight loss.” European Journal of Clinical Nutrition, (2013) 67, 759–764 DOI: 10.1038/ejcn.2013.90.
[11] Bueno, N., “Very-low-carbohydrate ketogenic diet v. low-fat diet for long-term weight loss: a meta-analysis of randomised controlled trials.” British Journal of Nutrition, 2013, doi.org/10.1017/S0007114513000548.
[12] Phinney, SD., “The human metabolic response to chronic ketosis without caloric restriction: preservation of submaximal exercise capability with reduced carbohydrate oxidation.” Metabolism, 1983 Aug; 32(8):769-776.
[13] Vogt, M. “Effects of dietary fat on muscle substrates, metabolism, and performance in athletes.” Med Sci Sports Execrcise, 35(6); 952-960.
[14] Volek, J, “Metabolic characteristics of a keto-adapted ultra-endurance runners.” Metabolism, doi: http://dx.doi.org/10.1016/j.metabol.2015.10.028.
[15] Attia, P., https://peterattiamd.com/the-interplay-of-exercise-and-ketosis-part-i/. Accessed 11/2018.
[16] If you really want to geek out on low-carb & keto research, you can find a comprehensive list of studies since 2000 at: blog.virtahealth.com/low-carb-research-comprehensive-list/.
[17] Sisson, M., The Keto Reset Diet, Harmony Books, 1st ed., 2017, ISBN 978152462230.

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