Tuesday, January 12, 2016

Part 2: Risks of Keto and Very Low Carb

Read Part 1 first in clearing up the difference between keto and moderate low carb diets, and my experience with each.

Next. If you are an Endurance planet podcast fan, you know we've discussed the benefits of very low carb (VLC) and ketogenic diets. There is not doubt that these diets can do a lot of good for certain folks and improve health--the research supports this--and it can even aid in athletic performance for those dedicated to the stringent protocol, but these diet extremes are not for everyone.

Thus on EP, it's our duty to share the pros and cons of certain diets to allow you, the listener, to make an informed decision hopefully along side your doctor/coach/health practitioner. The last thing I want is for "the wrong person" to start a keto or VLC diet because they heard it was sooo great, but not have all the facts and tools, and end up worsening their situation or health. Who is the "wrong person?" Generally: someone who's not in the right state of health, not metabolically fit, and/or a lot of women; you have to listen to the podcast with Tamsin for the full lowdown.

I did this podcast with Dr. Tamsin Lewis is to give the female POV without male bias. There are a lot of great guys out there who are able to look at the science and not just talk from a male-biased perspective (Peter Defty and Dr. Jeff Volek come to mind). But usually those who promote keto are male. And let's face it, us ladies shouldn't always have to take advice from the dudes ;) I personally am getting more emails and/or reading stories from female athletes who've messed up their health by poor dietary practices including keto. Women who heard advice about low-carb being awesome, so they tried it, had initial success (toned up, better energy, some performance gains, etc) then it backfired. Weight loss plateaued and/or they gained weight, energy crashed, performance crashed, hormones crashed, periods disappeared. And that's why I wanted to do this show.....

Furthermore, if you listen to other podcasts who praise keto (Tim Ferris, Jimmy Moore, etc) it's important to note many of these folks aren't endurance athletes either. That matters because they can probably handle keto extremes that endurance athletes can't, thus they give advice that doesn't apply to the triathlete and runner folk.

Hence, it was time to get 1) a female voice on the show to balance it out and 2) to talk straight to endurance athletes female or male, to show that keto is not always what it's cracked up to be.

So far with the outpouring of emails and comments I've gotten since releasing the show, it seems like we did what we set out to achieve in creating more awareness and depth to this topic. Women (and men) have mostly been stoked and appreciative of the show.

Why Bother Discussing VLC and Keto?
This actually brings me to an important point. If keto is risky why the hell even bother? You also may already assume or have heard that low-carb is "dumb" for athletes. Mainstream sports, especially the triathlon and running worlds, still largely promote the traditional high-carb diets, sugar-based fueling and carb-loading. Pizza and pasta parties are still a big thing. Sigh. However, the content you get on Endurance Planet in regards to diet and nutrition won't be what you've traditionally learned about sports nutrition nor what the USDA food pyramid recommends.

Why? Because we take sports performance to the next level and integrate concepts for better health, metabolic efficiency, and optimal living.

Most people will not optimize their health and performance as a high-carb sugar burner. It may work for a while, but eventually catches up in some way, shape or form.

So moderate low carb, high fat (LCHF) is usually a safe, healthy route, which I talked about in Part 1. However, a lot of people don't settle for "safe" and they want extremes! Those risk-takers lead us to new discoveries. Thus, we're seeing that lowering the carbs to a state of nutritional ketosis is effective, depending on the goal, and it's catching on. Keto is intriguing and "sexy" right now, and also easier to sell vs. the moderate safe approach. Keto has its pros: It can create a ripped lean body without training your ass off, control appetite, maximize metabolism, boost brain power and function, increase energy, increase clarity and productivity, prevent disease, balance health, and the list goes on.... In a clinical application, keto can also be life-saving and is shown to be effective in treating certain cancers, epilepsy, obesity, Type-2 diabetes, reversing insulin resistance and so on.

But what about for an endurance athlete? For the athlete who's healthy and fit enough to begin with, he or she may thrive off getting into nutritional ketosis (with appropriate carb cycling). It gets nitty gritty, but the evidence is there. Look to the low-carb guys in the FASTER study, for example, including Ben Greenfield and Zach Bitter. These guys are finding a level of fat-burning capabilities that we never thought possible. The more we can efficiently burn fat during endurance events, the more we can sustain and achieve--and not wreck our bodies with chronic sugar dosing. Seems like a win-win for the athlete who also deeply cares about health and longevity.

Zach, for example, just broke the American 100-mile record going 11:40, a 7:00/mile average. Ben trained for and raced Kona well on a keto diet in 2013. And even female athletes like pro ultrarunner Nikki Kimball are thriving off keto not only for endurance performance but mental and cognitive benefits (it's alleviated her depression). Dr. Maffetone has been promoting low-carb high-fat for decades and even has his current athletes like Dr. Amanda Stevens able to cycle in and out of ketosis--interestingly Amanda in 2015 had one of her best seasons to date after going this route, which we discuss on this EP episode. Vinnie Tortorich is a good example of someone for whom keot makes sense; he's a cancer survivor and endurance athlete who's seen real benefits of no-sugar, no-grain, keto-style diets.... how can you argue with how good he's doing vs. what could have been?

Keto can be healthy, beneficial, and a smart approach....

But YOU Matter
That said, for as many people for whom keto works or could work, there are plenty of people for whom it doesn't work or won't at all--to the point of risking a harmful backfire. That's why careful consideration is needed when approaching any diet extremes and we must take into account the individual.

Perfect example: In this article, Chris Kresser writes on prescribing individual diets for two different females with two different stories. One woman had Metabolic Syndrome, insulin resistance, and obesity; the other had Adrenal Fatigue Syndrome and Hypothyroid (interestingly, the latter woman's conditions were partially caused by a very low carb diet!). For the obese woman, Chris prescribed a keto-ish diet (15% carbs) and an intermittent fasting (IF) protocol. The woman with adrenal fatigue and hypothyroid received diet prescription that included moderate carbs (20-25%) and more frequent eating, no IF. That makes absolute perfect sense, and in the article Chris explains why.

What's right for you may not be right for me, and vice versa. What's right for a 40-year-old sturdy male athlete may not be right for a 20-something female runner with body-image issues. Hence the podcast with Tam...

The Podcast
Tamsin brings a lot of experience and expertise to the topic of diet and health for athletes as an Ironman champion, practicing medical doctor and psychiatrist, someone who's dabbled with LC diets, and also someone who's overcome an eating disorder. Her patients include female athletes who've suffered from dietary extremes like keto. So does she have the experience and authority? You bet.

We set up this show to be more geared toward women because they have the most "to lose" with keto. While males are not void of potential issues, they do tend to be more robust and suffer less hormonal disruptions when they do diet extremes. That said, it's certainly not impossible for a guy's health to tank with keto extremes.

The podcast highlighted potential risks of keto diets, especially risks for athletes. Furthermore, we wanted to help educate people on whether they are the right candidate for a keto diet or not, as some are more susceptible to the risks than others. It wasn't a keto-bashing podcast nor fear-mongering; although, I'm sure some will take it that way.

That link will also take you to the show notes, which has a full outline of keto's risks, which we discuss in detail; thus, no need to be repetitive on this post.

Did we discuss risks and side-effects that aren't necessarily backed by research, but rather anecdotal evidence? Yes. Not everything can be answered by "what the research says" and just because it isn't in the research doesn't mean it can't be true. Keto for endurance athletes (especially females, and even non-athletes) the way it's being done in modern times is relatively new and the research just hasn't caught up yet and/or it can't be done due to IRB issues. And even the research that has been done has had its hurdles....

"I remember all the flak we got for the Western States Study by the UCONN IRB...they were against athletes trying to run 100 miles on Low Carb and did not realize the athletes were running anyway and in this state....we finally got it through, but took a few months...." says Peter Defty, of Vespa.

If research is lacking, especially on females, then we can look at what's going on in the real world. There is a growing amount of anecdotal evidence on females--athletes or not--who've suffered poor consequences of keto diets. In my professional network, I talk about this with my colleagues quite often. It's real. It's not just opinions that were conjured up out of nowhere. And even digging around online you can find tons of stories of keto gone bad. Tamsin and I even shared some of our personal experiences from an educated POV. I hope it was clear that we were not trying to generalize the situation and diet-bash, but rather "bring life" to the topic.

Meanwhile, there is plenty of research showing the very real issues associated with female-athlete triad cases, and I can make an educated guess that there are plenty of triad cases that involve diets that are too low carb... this even gets into the psychology of the matter. Very important.

Tamsin said near the end that she would never recommend keto for any female athletes. A bold statement, and her opinion. Do I agree? No. But I respect her opinion, just like I respect the opinion of other guests who've been on EP whose opinions don't always align with mine. And besides that statement of Tamsin's, I pretty much agreed with everything else she suggested and learned more from her.

Even Defty, who's a nutrition genius and advocate of keto-style optimized-fat-metabolism diets, says that keto won't work unless health is there:

"Many females in today's modern world probably should not be in straight up NK [nutritional ketosis] .....they just are not metabolically fit enough to make it work. If you have an underlying condition its tough to get into ketosis and you will struggle to maintain it....as you mention and know there are a lot of really badly broken people out there including a lot of females....people who through trying to be healthy actually got very sick and compromised.....so until the underlying issues are solved NK is not going to work well and even backfire.....if you are pregnant doubly so. I see a lot of people who are wrecked by Low Carb because either they or the person who is coaching them thinks they get it but really don't. There cannot be underlying conditions," he says.

We have to understand everyone is an individual and brings a unique situation to the table. As such, let's work with individual needs not try to broadly recommend diets as being right or wrong.

We will have more podcasts on the diet matter. It doesn't end here...

For More Resources on Keto Risks

Ben's top-10 mistakes of keto and his article on keto dangers.

Is low-carb ruining your health by Kresser, and more on VLC.

Adverse reactions to keto by the Paleo Mom.


  1. I should have said - I would not recommend CONSISTENT USE of ketogenic diets for athletic women - unless they are very closely monitored by an experienced physiologist or physician :)
    I think the use of keto has many applications, esp. as we learn more about how to do it right. However, where I do not think it helps is in performance where threshold or near threshold efforts are required.

  2. I have looked for an answer to the question if Super Starch can be used during an endurance event if fat adapted without causing me to drop out of Ketosis. I have seen people say yes no problem and no it will knock you out of ketosis. What is your thought? I am fine sticking with fats as fuel but have 2 canisters of UCan sitting in my pantry.