Is It Possible To Be Extremely Active and Eat A Low Carbohydrate Diet?

Affiliate Disclosure

Low Carb & Ketogenic Diet, Podcast

Listen on:

In today's interview, I speak with a surgeon, engineer and relentless self-experimenter, Dr. Peter Attia (pictured above as he swims across the Catalina Channel), about whether it is possibly to be extremely active and eat a low carbohydrate diet.

If you've ever wondered whether it's possible to keep yourself in a “ketogenic”, low carbohydrate state and still swim, bike, run, lift and do other extreme sports and activities, then this audio will answer all your questions.

Let's begin with a video of a workout being done by Dr. Attia, who I interview in today's podcast:

Peter Attia

And he does all that while eating only 30-50 grams of carbohydrates per day!

Dr. Attia (pictured right) of Canada is a relentless self-experimenter who has spent the last two years examining the role of nutrition on all aspects of personal performance. He is a former McKinsey & Company consultant, surgeon, engineer, calculus teacher and an author of numerous medical and research papers.

Dr. Attia received his medical degree from Stanford University and holds a B.Sc. in Mechanical Engineering and Applied Mathematics from Queen’s University in Kingston, Ontario, Canada, where he also taught and helped revamp the calculus curriculum. He did his surgical training at the Johns Hopkins Hospital in Baltimore, Maryland. He also did a fellowship in surgical oncology at the National Cancer Institute in Bethesda, Maryland.

Dr. Attia's website, which we discuss during the interview, is

Here are the questions that I ask him:

You have an interesting story. How did you come to start your website,, and what is it that you are trying to achieve?

You appear to keep yourself very fit. Walk us through a typical week of exercise for you.

For any given day, especially on these exercise days, about how many carbohydrates do you eat, and what does your eating look like?

How about before and during a long workout, like a long bike ride. What do you eat?

What is the science behind how your body is able to accomplish so much exercise with so few carbohydrates?

What research is out there that has been conducted on people exercising very long, very hard or both while eating low or no carbohydrates, and what has been observed in the research?

Is there a “maximum” amount of carbohydrates that would be considered healthy for frequently exercising individuals, such as enough carbohydrate to keep liver glycogen stores full?

Was this style of eating an easy transition for you, and how can people expect to feel if they try to combine high volume or high intensity exercise with carbohydrate restriction?

Have you found a “ceiling” for how long or how hard you can go while in a carbohydrate restricted phase?

Do you feel or have you observed a need to include carbohydrate re-feeding periods, whether specific days of the week, periods of the exercise year, or seasons in which you may eat more fruit or more carbohydrates than usual?

Have you found that particular dietary supplements or strategies help active individuals to succeed with or adhere to a low carbohydrate diet?

Some studies have shown low insulin and a low carb diet to reduce thyroid function or cause leptin resistance. Is that true, and if so, is it an issue?

Click here for the full written transcript of this podcast episode.

Recommended reading as an additional resource:

Art & Science of Low Carbohydrate Living

Low Carbohydrate Diet For Triathletes

Recommended supplements for long workouts:

UCAN Superstarch – use plain flavor only (avoids the sucralose), 80-100 calories per hour

MCT Oil – use 30-50ml 30-60 minutes prior to workout

Other resources:

Blood glucose monitoring system

Ketone strips

Questions, comments or feedback? Leave them below.

Ask Ben a Podcast Question

127 thoughts on “Is It Possible To Be Extremely Active and Eat A Low Carbohydrate Diet?

  1. Ray Rico says:

    Hello. I have type II diabetes. All the research I have read tells me building more muscle will help with insulin sensitivity and help reduce blood sugar. The other information I have found suggests doing Hiit type training, which will also help with blood sugar. But Dr. Attia says in this interview that one of the variable on this is the amount of activity. He said some activities raises your ketone levels because it allows your liver to gradually access fats to break down to ketones and some type of activities actually suppresses it. The higher intensity exercises tend to lower ketones levels, where as lower intensity exercises (long bike rides) really raises ketones. He says that when he’s pushed the intensity of his exercising his liver goes nuts to get all that glucose out. And that checking his glucose before and after exercise he can see his blood glucose jump upt 30 or 40 points. So who is right? Hiit training or lower level intensity?? Thanks.

    Ray in Texas

  2. Esther says:

    Hi! I’m looking for a little help, as I try to be a keto-athlete, but sort of the other way around… And doing it properly is quite a struggle!

    I’m on a ketogenic diet for over a year. My headache attacks almost disappeared because of the diet, and in addition I perceive a much greater general fitness and improved body composition. This keeps me on it, not necessarily desired race performance. However, I do take triathlon very serious as a hobby and am also result minded. Now I am seriously struggling with fueling the high intensity 2hr+ rides as well as Olympic/70.3 race days. I would love to know how to properly approach this, whilst maintaining a keto lifestyle in general, for my own reasons. I do not want to deplete my body of anything, remain healthy and want to perform well in high intensity workouts. However, ketosis keeps my headaches down, and is a propose in itself….

    I tend to run into the pro – con Keto discussion all the time, and whether it is a performance boost when looking for info, while I’m just trying to work with the fact that keto basically is my lifestyle, while I still want to maximize my performance in triathlon and don’t mind to bump out of ketosis for particular workouts if that’s what it takes.

  3. Marisa says:

    Ben- This info is GREAT! Just to be clear, if you are looking to lean up, would taking MCT oil before a cardio workout help or is it better to just be in a fasted state? What helps burn more fat storage?

    1. I would start here:… and let me know if you have any questions!

      1. Carole Morgan says:

        MCT oil has great benefits, but when I first started taking it (15ml) it gave me stomach issues so I had to lower my dose and I took it with food instead of putting it in my coffee :)

  4. Ryan Thompso says:

    Curious, I’d like the best of both worlds; carbs and ketosis. Can i simply continue in a HFLC diet and add enough carbs for high endurance rides? I find UCan to be decent energy, though when i need high energy, its just not there. How can i straddle the line between HFLC and energy needed for high endurance rides? Or am i just kidding myself here. Thank you so much?

  5. Sambo says:

    Hi Ben,

    Just found your site. Awesome. Loved this interview and then combed through all the comments on this page searching for an answer to my question. Sorry in advance if you’ve answered it elsewhere but this was the page on your site where I just landed. I have been following Dr Davis’ wheat belly for a year and I am now interested in running a marathon which is how I found you.

    Question – Ketosis is reported as binary, so how long does it take to flip the switch? Can one be in ketosis and eat a higher carb meal or have a day where they drop out of Ketosis and get back in ketosis the following day. Can it be switched on and off easily and what effects does this have on performance.

    Also after reading all the comments and you mention Cold treatment to break the plateau of weight loss, what is that?

    1. it will take you, depending on your level of fat adaptation and how long you follow the biogenic diet, to to eight hours to get back into ketosis after eating a high carb meal. re: cold treatment, I"m referring to cold thermogenesis! Listen to my wim hof interviews!

  6. Dougie says:

    As I eat my bacon and eggs breaky fried in butter with cheese and mushies, I wonder the inevitable – how do I mop up all the butter without bread

    Given Peter seems to eat at restaurants a bit, how does he mop up all the fat of olive oil and what not in a not-so-ugly way? (I dont mind if Im in my bedroom tuning into the BG podcast, but when I’m out for dinner……you know…..)

    1. I personally just order a bunch of extra veggies when I'm at a restaurant and mop stuff up that way.

  7. Dougie says:

    Cant believe I found this!!!! Best interview ever!!!!!!

    Would like to know about sodium supplementing – not looking for an easy way out, but the fact is I can’t afford most supplements, would there be any dangers to just upping the salt intake (sea salt)?

    I read a Dr. Mercola article stating that sea salt isn’t good enough, still full of baddies, he says himalayan salt. But he was talking about the problems with the US seas…….are the differences in sea salt between the US and Australia? And is sea salt nothing to worry about, unlike what Dr. Mercola says?

    1. Yep, as long as it is sea salt and not isolated sodium chloride. Just be CAUTIOUS with brands…check out my article on salt here:…

  8. Robert says:

    Love Peter Attia. He’s a person who looks for answers rather than just trying to prove his beliefs.

  9. dlawiii23 says:

    Hey Ben! Is it possible your audio links in the post aren't working? I tried downloading and streaming and no luck. I also tried looking for this old episode in the iTunes stream but I'm not sure if I can go back that far. Thanks.

    1. We found the problem and fixed it. You should be able to listen to this one now. Sorry about that – and – thanks for the heads up!

  10. msnyc15 says:

    Hi Ben, great site thank you. I just discovered LCHF/Ketogenic lifestyle after trying to get back in shape after 5 years off after a Crossfit injury sent me off the rails. I am getting back into CF and will be doing boxing training as well so clearly am going to need some energy. There seems to be a wide range of opinions in what to eat/not eat on LCHF (e.g dairy yes dairy no) but since I'm trying to get back in shape which includes losing the 35 lbs I put on but increase CF and Boxing type fitness I figure I better do it right so thought I'd ask here.

    My basic take away on this so far #1 is I need to improve the quality of my food not just add a lot of fat and meat. I ordered high quality organic grass-fed beef/chicken/butter/eggs/cream/sour cream/bacon to start and am getting a monthly delivery of fresh made beef bone broth (and beef tallow to cook with). Still planning on keeping spinach/kale/tomoatoes and such as a salad base to add proteins too along with either homemade olive oil /. vinegar and/or homemade ceasar or blue-cheese.

    I also have a high quality Whey (Whey Natural) to which I plan on adding if it make sense post-workout (or pre as well):
    Raw Cacao
    Coconut Oil
    Amazing Greens Powder

    I was thinking of adding a combo Creatine/Glutamine/BCAA supplement I added to this as well and maybe Almond Butter.

    Do you think this is a good interpretation of LCHF especially as it applies to both weight loss (at first) and Crossfit type fitness (nope I don't look like your brother but do have a decent frame I'd like to add muscle to and get rid of excess fat from being sedentary for give years). Any insights appreciated!

    1. I would point you towards a couple of resources: this article… and this book… will really help you get dialled in. You may also want to print off a copy of my Superhuman Food Pyramid… and finally, I would be happy to have a one-on-one consultation with you to go really dig into the issue

  11. Lisa says:

    HELP!!! I’m perplexed and fustrated! I’m training for a marathon in May. I strength train two or three times a week and run an average of 40 miles a week and I have adopted a high fat, high proteins, low carb diet. The first two weeks were rough but now I’m cruising. I do carb refeed once a week on my long runs. Most days, I consume less than 50grams of carbs a day. I don’t eat processed anything or dairy only natural whey protein. No protein powders. I avoid nuts but eat vegetables and eggs and avocados and beef. A lot of it to keep my energy up. I don’t count calories. Okay, WHY AM I GAINING WEIGHT AND MY MEASUREMENTS ARE GOING UP?! This is so fustrating! Someone please… Thoughts… Advice… Are all welcomed! Thank you!

    1. Take a look at this –… and I'd be happy to help! Book a one-on-one consult and we will get it figured out –

  12. jasontshields says:

    Ben, this was THE best interview on Peter Attia and Ketosis that I've ever heard! I'm going to be joining your Inner Circle hopefully next month. I have mild cerebral palsy and autism and have been doing keto for about 3 weeks. Did a refeed over the weekend and feel fantastic. I've been devouring your articles on Low Carbohydrate "living" and was amazed at your brother's pics and how he is faring on a low carb lifestyle. Thanks to you and your book "Beyond Training" along with this interview, today was the first day that I actually felt "normal" on low-carb. Took the supplements that Peter and you discussed and I feel great. Am looking forward to seeing how this lifestyle will improve my coordination and spasticity. See you on the inside (inner circle).

  13. joeflah13 says:

    Hey Ben! I love the info here on your site and it's really helping me along my ketogenic journey. I know this is an older post, but I was hoping you could point me in the direction of the ketogenic/resistance training studies Dr. Attia referred to at ~42 minute mark? The ones he speaks about after the Volek study which show LBM increase with simultaneous fat loss?

    And another question I had lingering from the podcast: I know both you and Dr. Attia recommend consuming BCAA/EAA during or around training. My main form of exercise is resistance training 4x a week for about 45 minutes. Do you think this type of training protocol would benefit from BCAA/EAA consumption, and would I be able to stay ketogenic while taking those supplements? I was under the impression that plasma leucine levels raise insulin independent of BG, so I stayed away.

    Any info would be greatly appreciated! Thanks and keep doing what you do!

    – Joe

    1. If you are lifting in a fasted/ketogenic state, I would definitely suggest taking something like… to keep you from catabolizing your own lean muscle BUT this would be a great question for the podcast – call it in and I will do a deep dive!

    2. You might also benefit from looking at the answer to Jason's question on this page…

      1. joeflah13 says:

        Thanks for the speedy replies Ben! Just submitted a amino-related question via speakpipe so hopefully that pops up on the next podcast! I've been staying away from any kind of amino supplement intra workout and even post workout whey out of fear for a non-blood glucose mediated insulin spike, but I've always wondered if those fears were unfounded or not. If I could stay in ketosis while supplementing, I'd get the best of both worlds.

        1. You should also take a peek at my response to Connor on this page, I think it will help you understand the digestion process a little better…

          1. joeflah13 says:

            Clutch news! Reading that over right now, thanks for all of the help!

  14. Stephanie says:

    Hi Ben! New to your website! Love your articles! What would eat then instead of gels on a marathon?

    1. I'm working on a post about that very subject for next Monday. Stay tuned! In the meantime, you can check this out:

  15. SheilaMikulin says:

    At the very end you ask Peter about thyroid AND leptin resistance. He discussed the thyroid but not the issue with leptin. Is there a way to find out the answer to this?

    1. This may be WAY more than you are looking for… but take a look at this article… or this one…

  16. Andy C. says:

    There are some good books that may be of interest to anyone on this subject. Everyone curious about performance in relation to low carbohydrate diets should read both "The Art and Science of Low Carbohydrate Living" and the "Art and Science of Low Carbohydrate Performance" by Steve Phinney and Jeff Volek. I would also recommend Body by Science by Doug McGuff.

  17. Lisa JS says:

    Hi, I was curious about Peter's aside about the breakdown of dairy in the body. He mentioned that there is some controversy about dairy lactose breaking down into sugars. I would be interested in hearing the evidence for that or getting pointed to a link. I assume he is not just talking about lactose-intolerant populations.
    Many thanks. L

    1. I asked him and he said:

      Hi Ben,

      About half of dairy sugar is broken down into lactate which goes back to the liver via the Cori cycle for GNG. The remainder is not particularly insulin-generating. But there are individual differences. In some it is insulin generating. I don't think we know why there's a difference.


  18. Freddieboy says:

    Hi Ben, I know this is an old post, but didnt know the best place for my questions, which are:
    1, I seem to recall that you posted somewhere, can't find it right now, that low carb probably wont work if you very slim. I'm 5'10", 136lbs, so very slim. Can you please elaborate on your reasoning behind this statement please?

    2, You say in several places that you often eat 100-15g carbs per day, now reading both the recent Volek and Phinney books, they suggest that's a sort of no-mands land, it's either full ketosis or more carb heavy, i.e above 150g they suggest from what I remember. What's your view on this?
    Then again MDA and PHD seem to suggest 100-150g carbs a day is good, confusing?!

    Many thanks

    1. Hi Freddieboy,1) The less storage fat you have to burn the more stressful low carb is on your body. Really skinny people seem to do better on cyclic low carb when it comes to reducing the hormonal milieu.2) Volek and Phinney aren't taking into account the extra glycogen burn from endurance sports. In a sedentary or lightly physically active person, lower carbs is fine. But for anyone exercising more than an hour a day I recommend at least a baseline of 100g.Ben

  19. conor says:

    I’ve often heard about the struggle of the transition phase into a ketogenic diet, being “painful.” During this phase, or throughout this intake transition, can caffeine be used for increased energy during this phase? or can caffeine be used at all while in Ketosis?


    1. SheilaMikulin says:

      Conor – You may want to check out bulletproof coffee – @ Tons of info there.

      1. Nice one, Sheila. You nailed it. I used BPCoffee throughout my Great Ketogenic Experiment –…

  20. You say to only take the plain flavor to avoid sucralose. However, I believe they use stevia as a sweetener not sucralose.

  21. Misty says:

    Also, Please correct me if im wrong, but it seems if one is in a constant state of ketogenesis, that the body in way interprets this as starving…or rather stress. Also, I was also wondering if we were out in nature, wouldnt we be mostly eating plants, fruits, nuts and some game? Just some thoughts…

  22. Misty says:

    I am in favor of a low carbohydrate type of diet. The idea of consuming 75-125 g on training days with a higher amt of fat does seem beneficial. However, this particular diet he is talking about appears extreme if followed long term. I know others have brought this up, but i cant help but to wonder the detriment of this type of diet on a young woman or woman of childbearing age and reproductive health..
    just curious…

  23. I have noticed when I lift in a fasted state I a no able to lift as much. Probably because I am low on carbs.

  24. Achia says:

    How much exercise is needed a day to lose weight on a low carb diet .
    and i have 40 pounds to lose how can i do it fast ? help people !.

    1. You don't necessarily have to exercise PER SE, but being physically active, standing more, etc. is important, and structured exercise can accelerate your results! Losing 40lbs fast=bad idea. that is how people mess up their metabolisms and bodies. 20 weeks is a good timespan to shoot for, at around 2 pounds per week. If you need help or a phone consult, go to and click on Coaching & Consulting.

  25. Kenneth VD says:

    Hey Ben,

    I was wondering if you could clear up something for me.
    What I've been taught is that the primary fuel for the brain is glucose. I know that it can also run on ketones, but that obviously, ketoacidosis is a problem.
    If it is true that the brain prefers glucose as its fuel, what are the possible long term effects of burning ketones primarily? Or do the metabolic systems eventually adapt to the ketotic state?

    Overall, I've been toning down the amount of carbs I've been eating, but are what the long terms effects of being on a high fat, low carb diet?
    Thanks for the post; great interview.


    1. the brain can burn about half of it's fuel from ketones, and a low carb diet of 50G or fewer of carbs per day will increase monocarboxylic transporters (for ketones) significantly in brain cells, which increase potential magnitude of ketone use as a fuel. Potential side effects of high fat low carb are simply tiredness if you do it wrong and maintain greater than 150g/day of carbs (less in many cases, depending on activity) because your blood glucose is somewhat low, but your blood ketones are also below the 0.5 millimolar threshold where their primary use as a fuel begins to kick in. So if you half ass the diet, it sucks.

      1. Kim says:

        Are cognitive abilities or functions compromised when you are in this purgatory area of 50 to 150gm? I actually stay in the 55 grams of carbs per day with occasional higher slip ups on weekends.

        1. Yes, but just for the first 10-14 days…

  26. ismail khalil says:


    1. Dougie says:

      dude, stop shouting, you’ll wake the baby….

  27. Brennan says:

    UCAN follow up. This is the second superstarch (gener8) I have tried and my body just does not seem to be able to digest it well which seems strange given that is supposed to be one of the benefits. I felt a bit ill for the first 30+ minutes (really mild nausea similar to taking vitamins on an empty stomach). On the positive side I did feel like my energy level was much more stable for my 50 mile aerobic ride once I got over that feeling. Not sure if that feeling is worth the benefit. I tried to drink a little more after 2.5 hours (3 hours after the first package) near the end of my ride and my body simply did not like it so I stopped after a few sips. I am going to give it another try given that I committed to a few packages but I wondered if anyone else had similar experiences and or advice. Is an adjustment period common? Maybe I drank it too fast but I can normally eat just about anything with minimal issues. I am currently eating lower carbs (500-600ish calories with increases on heavy work out days) and gluten free but I had problems with gener8 back when I used to eat everything.
    Thank you!

    1. How much UCAN did you eat, Brennan? Also, how much have you focus on optimizing gut flora (taking probiotics, using digestive enzymes, avoiding gluten, etc.?)

      1. Brennan says:

        Thank you for the quick response. First thing in the morning I had one package, 26 grams, 30 minutes before my ride per their directions and probably about 5 grams before I stopped drinking it 2.5 hours into my ride. I drank the first package in 5 minutes or so. I don't specifically take any probiotics or digestive enzyme supplements but as of the last 6 months I have been lower carb (500ish cals), gluten free, and I generally eat at least 2-3 servings of each of the following foods every week ( sauerkraut, greek yogurt, blue cheese, living fuel super greens). Other drinks I have used recently without issue are Solar synergy, gu brew, accelerade.. although I usually have a banana or two pre ride and don't chug 25 grams of any of those drinks in 5-10 minutes. I think my prior experience with gener8 and the fact that even when I had sips of UCAN 3 hours into my rdie is what raised a red flag for me. More details than you asked for. I have been training off and on for runs (10k-marathon) and olympic tris for the past 8 years and the only things I recall having GI issues with are gatorade and super starch. I generally don't have GI issues… that I am aware of anyway. ; )

        1. This sounds like it may be an enzymatic issue for you, possibly some kind of starch amylase deficiency. I'd try a digestive enzyme supplement…

          1. Brennan says:

            I will give it a try. Thank you!

  28. barbara says:

    This is a fab interview you ask really fine questions that I was interested in knowing about. I love your site.


  29. Nick says:

    I’m particularly interested in the positive RQ effect in keytosis or ketogenic state. As an age group triathlete Im striving to go as fast as possible while remaining on the right side of the anaerobic line. If I can potentially improve RQ through low carb diets by burning fat then I become relatively more efficient – right?

    This podcast is potentilly life changing – from an athletic perspective and I need to understand better whether a ketogenic state is necessary to get the benefits on threshold and RQ?

    1. Exactly, Nick…a ketogenic state per se wouldn't be necessary, but watching carbohydrate intake would be for sure…

  30. Glenn Whitney says:

    So this helps prove that humans can thrive on almost any combination of macro nutrients you can imagine. But thrive for how long? Is this an optimal diet for reproductive health? Evolution can only be understood in the context of reproductive fitness.

    A few other points to consider:
    – When it is cold in the Arctic, it is cold all day, all night and cold in the shelter, not below freezing but cold. The air people breath 24/7 is cold everywhere, in a way it rarely is below the Arctic
    – Even in the Arctic, where Inuit and other Artctic people have lived, there is a warmer season, in which a wider variety of foods (including carbohydrates!) are consumed.
    – If he hasn't already read it, I highly recommend to Peter (as a Canadian) the anthropology book "The Other Side of Eden" by Hugh Brody, who lived among the Inuit for many years
    – Also recommended is the BBC's Human Planet. In particular, there is an episode on Narwahl wale hunting. The skins apparently is highly sought after because it's one of the rare sources of Vitamin C in the native diet

    1. I totally agree about the reproductive fitness, component Glenn. I would say if we're talking about a *strict* ketogenic diet, the answer is probably no. Cycling ketogenic? Like winter? Probably.

  31. Billy says:

    Ben can a ketogenic state be done on a plant based lifestyle and if so how?

    1. Sure. Just eat lots of plant based fats like avocados, palm oil, coconut oil and olives, and avoid the typical vegeterian higher carb approach.

  32. Brennan says:

    should have been: "comments you have made about Super Starch, GenR8 etc. in the past ->versus<- this podcast"
    Thanks again.

  33. Brennan says:

    Hi Ben,
    I am trying to wrap my head around the various comments you have made about Super Starch, GenR8 etc. in the past with this podcast. Is the basic summary that you only recommend it for folks on low carb diets during low intensity long (2+ hours?) workouts/races? Do you consider GenR8 and Super Starch comparable for this purpose. I tried unflavored GenR8 before (although I was not low carb then) and was not a fan of how my body digested it despite easy digestion being one of it's intentions. I am not going to quote you out of context but your prior less flattering comments about UCAN and similar products along with comments mentioning they spike insulin levels have me confused. p.s. All this started because I tried using the free shipping code that was sent out in today's text but it did not work… which led me to search the site for UCAN to see is something was posted which lead to my question. I guess it's good it did not work. : )
    Thank you for your time.

    1. Hi Brennan,

      A few years ago, I was preaching to eat lots of whole grains. ;)

      Basically, GenR8 results in a higher insulin release than Superstarch. In the context of low carbohydrate eating and blood sugar stabilization, I am a fan of Superstarch due to it's very low rate of glucose spiking.

      I use it for workouts during any time of year I want to be in low carb state. Not using it for races yet, because I go way to hard in races and I want more rapid sugar spike.

      P.S. The free shipping code UCANVIP works at…

  34. trainwithmeghan says:

    How many calories does Mr. Attila consume a day on his diet? Which diet are you a proponent of? Fat? Paleo? Primal? INFORMATION OVERLOAD!
    Also I noticed that all these Doctors are doing all sorts of diets and you never hear the elite athletes and pros in the olympics cutting out wheat, or this that and the other and they are performing quite well…. I mean what does Meb K and Deena Kastor and Kara Goucher, Chrissie Wellington eat? EVERYTHING in moderation…

    1. I'm not a proponent of any diet. I just eat real food, and avoid eating much more than 100-150g carb on any workout days, and less than that on non workout days.

      A TON of pro athletes are going gluten free/wheat free now. Look at Novak Djokovic, Garmin-Transition cycling team, LPGA golfer Sarah-Jane Smith and New Orleans Saints quarterback Drew Brees, professional triathlete Heather Wurtele…etc.,

      And remember that a ton of these athletes DO NOT KNOW what they are doing to their health long term.

    2. Dougie says:

      I’d like to whey in here (haha, get it, whey, as in, like, protein, coz this is about nutrition………I was funny once, trust me)

      Ben knows 2000000000 billion million more than I do about anything slightly fitness related, but I’ve also heard the LA lakers and James Lebron are trying lower carb diets, I know for a fact (thanks to Michael Smith), that Usman Kwahja, Dave Warner and Shane Watson are on carb-restricted diets, and I have reason to believe Steve Smith is to and before retirement Michael Clarke and Mitchell Johnson were too. Also, Port Adelaide and Melbourne Football Clubs have experimented with carb-cycling diets and I think Melbourne is continuing too.

      And I remember hearing on tv once, long before I know anything about fitness or nutrition, that Gary Ablett is on a paleo diet.

      Come on. Gary Ablett AND Lebron James AND Dave Warner??? What more do you want???

      I’m not trying to promote low carb diets here, just thought you’d be interested to know to know there are a few low carb elite athletes out there, and the names I’ve put up are elite elite – they’re the best of the best (except Port Power, who are average except for the year they started experimenting with the diet, and Melbourne who are all round shithouse and will probably stay that way for decades, as they have already…….I feel for Melbourne supporters………that said, given my bombers have been f**ked over by WADA, Melbourne might get a win this year…..)

  35. Nancy says:

    This was an extremely informative podcast, thanks! I have been wondering whether the ketogenic state might be good for those of us females genetically prone to the "pear shape". I am an athletic pear, i.e. thin and muscular on top and mushy and muscular from the waist down (argh!). Now that I am nearing menopause, it's getting more pronounced, despite all my best efforts (avid cyclist, medium low and healthy carbs, low sugars, clean eating, etc.). I am hypothyroid, also, and on top of that hypercalicuric (bad for bone density), just to confuse matters!

    I wonder whether sugary, high carb exercise fuel has done me in, even though I've used primarily maltodextrin based fuels and only under high exertion. I add on miles and intensity and nothing changes. Depressing.

    I read the following in an older endocrinology textbook, next to a photo of a woman who looks just like me (and my mother): "The acquired syndrome of upper body lipoatrophy with lower body lipohypertrophy, seen almost exclusively in women, is associated with recurrent infections and glomerulonephritis. Several of these patients have a distinct alteration in complement metabolism, with accelerated catabolism of C3 (subscript 3)." Peter or Ben, can you help me understand this: "alteration in complement metabolism/accelerated catabolism of C3"?

    Also, what is the thinking on carb-y recovery food while on a low-carb/ketogenic diet? I've searched Peter's blog for his recovery recipe but haven't found it. I'm guessing Peter's recovery recipe would differ for a long steady-state endurance ride/run vs. a higher-intensity or mixed endurance/intensity training ride or race?

    Thanks for any input you can offer!

    1. I'll be talking about this more in my upcoming book on body typing (stay tuned to for that), but in a word: yes – especially in females predisposed to adipose tissue storage, this will help tremendously with mobilizing fat stores and keeping more fat from getting distributed on your pear shape.

      Also, the complement system is a group of proteins that move freely through your bloodstream. The proteins work with your immune system and play a role in the development of inflammation. There are nine major complement proteins. They are labeled C1 through C9. Basically, the excess adipose tissue can cause some disruption of C3.

      Recovery carbs are overrated unless you're doing some really hard or long workouts. I have an entire garage with shelves lined full of recovery powders of maltodextrin/protein blends that I've never touched. I usually just have some coconut milk and protein post workout – no matter whether intense or voluminous.

  36. steve says:

    Ben, Peter – you've gotta appreciate how this sounded. "After I ate all the fat I wanted while minimizing all carbs and only using vegetables as a way to eat more fat, the thing I realized I was missing and needed was more salt!" Seems like a very elaborate April Fool's joke.

    In all seriousness (and after I concluded that nobody is joking here), I had never considered a low-carb diet before, for all the reasons you typically hear. For some reason this interview persuaded me that this might be worth trying for 12 weeks. I listened to the interview twice and spent the better part of a day reading I'm not sure I'm ready to go all-out on the ketogenic thing, though. So – as an experiment – I was wondering if these three strategies made sense to you's..

    * Eat a typical low-carb diet by eliminating starches that I'd otherwise normally eat (if dinner is a steak with broccoli and a potato, just skip the potato.)
    * Eat a portion of carbs after a workout when I'm more insulin sensitive (eat that potato.)
    * Avoid full-fat dairy (cheese, mayo) and instead buy low-fat – not because the fat is bad for me, more to cut back on the calories a bit.

    I'm 6'6" and probably at least 60 lbs overweight, but still manage to finish endurance events, including 100-mile ultras. My goal for this would be to finally drop that extra weight so I could perform better..

    1. Hi Steve,

      Here are my thoughts in caps:

      * Eat a typical low-carb diet by eliminating starches that I'd otherwise normally eat (if dinner is a steak with broccoli and a potato, just skip the potato.) THIS EXAMPLE DOESN'T HAVE MUCH FAT. THIS TYPE OF DIET ONLY WORKS IF IT'S *NOT* LIKE A TRADITIONAL ATKINS DIET…SO YOU NEED MORE FAT.
      * Avoid full-fat dairy (cheese, mayo) and instead buy low-fat – not because the fat is bad for me, more to cut back on the calories a bit. NOT A GOOD IDEA. CUT BACK ON CALORIES BY RESTRICTING CARBS AND MODERATING PROTEINS, AND ALLOW MORE FAT (PREFERABLY FROM NON-PROCESSED SOURCES).

      1. steve says:

        Thanks Ben. I guess I don't know what a traditional atkins diet is. Can you clarify the difference? Is it as simple as emphasizing protein instead of fat?

        1. Traditional Atkins is high protein. Ketogenic/low carb diet is best done and better for body when it is high fat, moderate protein, low carb.

  37. Sergey says:

    Interesting interview. It is very impressive how our bodies can adapt to various type of fuel and still perform on a high level. At the same time why do we need to go that extreme up to a point that we produce ketones all the time. There isn't pure fat laying around in nature, and provided that we have carbs and/or protein in our diet our bodies don't stay in ketosis. As it was mentioned in the interview the preferential fuel for humams is glucose.
    The ketogenic diet may help unhealthy individuals who were on SAD diet for several decades, but will healthy people benefit from ketosis? Do we have any data how this diet affects health and longevity long term. By health I really mean health, and not weight management what most people in USA worry about. As a former freestyle wrestler I know that in order to cut weight the first thing you do is remove all carbs from your diet, and as soon as you add carbs in your diet the weight goes back to original. Dr. Attia stressed out several times in the interview, that in order to stay in ketosis you need to carefully measure your carb and protein intake, otherwise your go out of ketosis and feel worse. It is hard to implement for most people.

    1. Sergey…there really isn't much of *anything* laying around in nature that doesn't require some kind of harvesting or preparation, except perhaps fruit. Animals, grains, plants, etc. all need some kind of labor to actually make edible – whether you're getting carbs, protein or fats from them.

      We do have data about ketosis, possibly as far back as Ancient Greek medicine…

      Now, all that being said, I tend to favor at least keeping liver glycogen stores full, at about 100-150g of carbs per day, and then eating slightly more than that if you anticipate a long, exhausting effort approaching, such as, say 10 hours of redlining your body during an Ironman triathlon…

      1. Sergey says:

        The Wikipidea page does say that there may be complications.

        Dr. Attia reiterated several times that ketogenic state is binary, you are either in it, or not. This is not scientific, but I think it corresponds to two states that our ancestors could be in, they either have food or they don't. Producing ketones is probably a defense mechanism to survive for long time periods without food supply.
        By purposely eating 90% fat we trick our body which "thinks" that it has no food and continues producing ketone bodies.
        A healthy individual should be able to process huge amount of carbs ingested in one meal, but we know that long term high carb diet in the form of simple sugars and processed food may shutdown insulin production and increase risk of developing diabetes. Is it possible that long term ketogenic diet will shutdown our ability to produce ketones?

        1. Ketones aren't hormones, they're metabolites, so probably not – as ketones and insulin are produced via two entirely different mechanisms.

  38. Bill says:

    Great interview. What would the effect of moderate alcohol consumption be on ketosis (in the form of, say, martinis, or red wine), as it is not a carbohydrate? Thanks.

    1. Your liver can make ketones out of alcohol, so technically when you drink you can continue to produce ketones and remain in ketosis. But alcohol converts more easily to ketones than fatty acids, so your liver will use the alcohol first, in preference to fat. So it kind of puts fat burning on hold.

      1. Bill says:

        Thanks Ben. That's the clearest and most concise perspective on this that I've heard.

  39. Jeff says:

    I'm starting to get confused with all this information. Ben, are you or are you not in a ketogenic state? I follow the Low Carb for Triathlete's Diet. I'm afraid of dropping further carbs because of performance reasons. Would I my performance suffer if I went to this extreme?

    1. I occasionally go into ketogenesis Jeff, but not during race season, as I can go faster when I instead go low carb, but closer to 300-500 calories of carbohydrate per day, instead of 100-200…

      Low carb triathlete is not ketogenic. It's closer to that 300-500 cal recommendation.

      1. alan says:

        i am with jeff, if you go low carb and don't get into ketogenic state is it still beneficial or do you need to be in a ketogenic state to allow your body to burn fat over glucose? i keep hearing him saying it is a binary proposition- either in ketosis or not!

        1. You'll still be burning a significant amount of ketones if you're on a low carb diet. But a strict ketogenic diet is, in my opinion, not very compatible with something like Ironman triathlon training, so there are some sacrifices that need to be made on that level. In other words, you'll be burning more sugar than would be optimal for your health – but that's a choice you have to make.

          1. alan says:

            thanks ben. that was a pretty amazing interview. have you interviewed volek or phinney? not sure how they could be any better but love the topic and would love to hear more about how to work more fat into the diet. it is easy to fall into the trap of upping the protein instead of the fat. 90% fat diet seems unattainable! keep up the great work.

          2. I've tried to get Volek and Phinney on, but so far, haven't heard back from them…

          3. Jeff says:

            I've used the Low Carb Diet for Triathlete's book for a while but eventually went back to Ben's book Holistic Fueling for Ironman. For me this has simply been the easiest fueling program to follow. Sustainability is key when it comes to nutrition. I've always felt best following this book during training and I've tried some other nutrition books like the Paleo Diet for Athletes, The Thrive Diet for a while and a few others. The fact is the holistic fueling book does contain anti-inflammatory foods and that's exactly what the body needs during Ironman training. It doesn't need more physical stress from diet or from going in a ketogenic state. That's why I stick to this protocol now and really ingest high quality foods while training. Ben if I were you I would promote Holistic Fueling for Ironman way more just because it's a diet that can be sustained because your not excluding anything, your just being smart about what you ingest and when.

  40. Chris Colvin says:

    Hi I just watched a few extra videos on Dr.Attia ,,,,, very interesting to say the least … Now to listen to the podcast …. cheeers for the great podcasts

  41. feerlessfood says:

    Sorry if I missed this is the interview, but what are the implications of eating a significant fat source like MCT or coconut oil before a morning workout versus going into that workout fasted? Looks like the overall calorie content wouldn't be too different so how much effect on energy and hunger would this have? Thanks Ben!

    1. If you're already skinny, don't want to dip into essential fat stores, and don't want to lose muscle during a fasted workout, that is one reason. Another reason is that you'll definitely feel more energy from circulating triglycerides liberated from MCT or Coconut oil, vs mobilized storage fat. I've tried both and the former rules.

      1. Justin says:

        Just curious, from your experience, was the perceived difference in available energy that much more noticeable when trying to get the body to mobilize energy from body fat stores versus taking a few teaspoons of mct oil ?

        Also in case you were wondering, yeah I got a call from 2012 and it asked me to come to this page and pose a question.

        1. You get more energy from MCT's just because it's exogenous and exposes you to extra calories!

  42. Edle says:

    Peter Attia said he had reviewed several studies on the link between low carb / ketogenic and thyroid. If you could provide a reference to these studies, it would be great. I am also yet to see a woman who was lean/low body fat to begin with, who then had success with ketogenic diet and endurance. Estrogen affects glucose and free fatty acid metabolism. But maybe such females exist?

    1. Start here, Edie:…

      Peter said to me:
      The bigger issue is not if we slight changes in T3, rT3, TSH, T4, etc. It's how *clinically* significant are they?

    2. dannyjalbers says:

      Paula Newby Fraser does not carb load, so am going to assume she has excellent fatty acid oxidation ability.

      You are not going to find naturally thin women who do keto… its a hard life and most people who do keto have to be compelled to it via diabetes or obesity.

      Keto is not an easy path.

  43. Josh Cox says:

    Well I know many vegetables are mainly carbs, so I figured you don't consume many. If true, I was wondering if you just supplement with isolated vitamins and minerals is all (as fat and protein are generally low in micro-nutrients). I'll have to read this one.

    Thanks again.

  44. Josh Cox says:

    With all the fat and moderate protein where is he getting his actual nutrition (i.e. vitamins & minerals)? Maybe I missed it, but is he supplementing with something to give him these things? Where's the vegetables?

    Also, on average, how many grams of carbs are you consuming on a normal training day, Ben?


    1. Josh Cox says:

      Discard my question for Ben. Just read the most recent article on the race you completed. Nice splits, BTW!

    2. Josh, for my normal training days, check this post:…

      Maybe Peter can answer your other question.

    3. Peter Attia says:

      Which vitamins and minerals are you referring to? I get my nutrition from the food I consume. Some things (e.g., salt) I need more of than a person eating lots of carbs, but many things (e.g., vit C) I need a fraction of compared to high-carb consumer. If you want to understand this in detail, I'd recommend this book:…

    4. marcus wolford says:

      I also think it would be helpful to keep in mind that meat is the most nutrient dense food. There are not many essential nutrients in fruits or veggies that you cannot obtain from meat, especially egg yolks and organ meats.

  45. Ben, Is the 'Superstarch' referred to the same as Palatinose (isomaltulose)?

    1. Peter Attia says:

      No, Superstarch refers to one very specific product which can only be sold by one company, Generation UCAN, who has the worldwide exclusive license to sell it for nutritional purposes. Here is their site:
      For your application this is a must-have.

    2. No – see Peter's reply. Also, I only use the plain flavor of this stuff, as the others have sucralose:…

  46. Great interview Ben. I specialise in multiday, non-stop endurance running (always over 500 miles in 6 days). I fuel on low carb. Is my sodium requirement going to be raised during races as Dr Attia mentioned?

    1. Maybe. You're the best judge of that. Do you find you're getting dizzy, losing balance, cramping, etc? If so, it's possible your kidneys are dumping sodium…

      1. Very occasionally had cramping but none of the other symptoms

  47. Robert says:

    Thank you for putting this information out there. I lost over 100 lbs and still have a ways to go. I noticed that while training for my first marathon that I stopped losing weight totally. Looking back, I was very high carb and coupled with liberal use of gels and other fuels, I sabotaged my weight loss completely. I now know that that was the reason. Talk about frustration. I went low carb and dropped 25 pounds in about 2 months. I have since stalled again but I now know that the carbs are the first place to start looking.

    Thank you for your dedication and commitment to education and then sharing your findings with us. You are greatly appreciated.


    1. If you're now stalled, and lowering carbs doesn't do the trick, consider that you may be leptin resistant from going high carb before. Consider cold exposure+good sleep to bust through that.

  48. Keerthi says:

    But inspite all the weight training he still looks very very thin and lean. I mean he has really no arms and legs. May be its not possible to build more muscle and look good with a ketogenic diet.. just saying.. he is fit and healthy as hell though

    1. Seriously – he has no arms and legs? The dude actually is pretty fit, and in my opinion has significant muscle in his arms and legs, unless you're comparing him to somebody like Ronnie Coleman…

  49. Reka says:

    I’m wondering why this is still a question and why do people try to justify eating tons of carbs with the excuse of “I need it, I’m active, the brain needs sugar” and bullshit like that. Most people eat around 70% carbs at least, and this is the only non essential macronutrient.

    1. That's what we're taught. I took multiple 400+ level nutrition classes in graduate school, and that's what we learned. That's what most docs learned. And it's people who took those same classes, but didn't learn any better later on, who are writing articles, advising patients, doing nutrition consults, etc.

      Plus, a high carb diet supports the majority of American corn and wheat production.

    2. alan says:

      i am on board with the grains, but have a hard time believing that you really don't need to eat vegetables, as steve indicates. i don't know that he is wrong, just hard to fathom.

  50. JLS says:

    Ben, You mention that this diet is particularly good for athletes looking to lose weight… but how about those who are struggling to keep on weight and calories to the point where there isn't enough strength to get through the day let alone a workout (I am a sprint/international distance triathlete). I am currently on a rotation diet that is supposed to be low-carb – temporarily for health reasons – but it has been a real struggle, and I am noticeably losing strength, energy, and I even see losing muscle.

    1. JLS, it's certainly *easier* to get adequate calories from fat than it is from carbs, and metabolizing fat results in less metabolic damage, creation of free radicals, etc. If you're losing strength, energy, etc., you may want to go slightly higher carb on your weight training days, but I'd also look into your micronutrient status, and make sure you're getting enough vitamins, minerals, etc. Also, the symptoms you've described suggested you may have some hormonal deficits too, so you may want to get those tested…

  51. vishal mehta says:

    there are any implications if we rely on a low carb diet

    and if we succeed it that benifit both grow muscle and loose fat

    1. Well Vishal, for building muscle, it kind of depends. I've found that it's better for burning fat, as lifting weights as much as is necessary to build significant muscle does require constant depletion of muscle glycogen. However, as I wrote in this article, you can still build muscle (albeit slowly) at as few as 800 calories per day:…

Leave a Reply

Your email address will not be published. Required fields are marked *