Dear Mark: A New Whole Grain Study, Advice for a Teen, Broken Leg Sprints, and The 3 Mules

For today’s edition of Dear Mark, we’ve got four questions and four answers. First up, there’s a new whole grain study, and some people are claiming it demonstrates that low-carb diets will lead to early mortality. Does it do anything of the sort, or is this yet another flawed observational paper? Next, a teen on top of his diet game who hopes he’s doing it right writes in with a list of questions. I answer them. Next, what can a person recovering from a broken leg do in the way of sprinting? Or should she just focus on recovery? Finally, a wild and free man is roaming California with three pack mules, flouting convention and leading a nomadic existence. Police are occasionally called and media attention is often attracted. What are my thoughts?

Let’s go:

Now I am confused. Did you see the new study published in JAMA which states that the newest research demonstrates that a diet without grains decreases ones longevity?

Trying to do the right thing, however it becomes confusing when JAMA publishes a recent study that says the opposite.

I would love your review and opinion.

Thank you,


Yeah, I saw it. I don’t think much of it, to be honest.

Did you see the article in Shape magazine? Because the author of that piece made the same mistake I worry you’re making: she used an observational study which looked at the association between whole grain intake and mortality to conjure up a conclusion about low-carb diets and mortality. The original JAMA paper found modest associations between whole grain intake and protection from all-cause mortality and cardiovascular disease mortality. It made no mention of low-carb diets.

The authors were using existing data from older and ongoing studies (Nurses’ Health Study and Health Professionals’ Followup Study) to find associations. They didn’t place one group of subjects on a high-grain diet and one group on a low-carb, low-grain diet. This was a hodgepodge of data requiring extensive massaging.

Now, could it be telling us something? Maybe. I think it’s fairly clear that whole grains are better than refined grains. Whole grains retain the fiber, the bran, and whatever vitamins, minerals, and antioxidant compounds that grain refinement eliminates. Moreover, whole grains are less likely to appear in processed junk foods, while refined grains provide the bulk of baked goods, junk food, and other packaged garbage. So whole grain eaters are by extension consuming less processed junk food.

What’s interesting is that controlling for bran intake eliminated some of the positive associations with grains in the paper. That is, according to the data, it probably wasn’t the “grain” doing it (if any food was “doing” anything, of course) but the “bran” — which contains most of the fiber (some of it prebiotic), the fat, and the antioxidants. As for the germ of the grain, germ intake had almost no effect on cardiovascular mortality.

There’s nothing to see here. If you eat grains, make sure they’re whole (and possibly fermented), I guess?

Hey Mark, I love all your content!

As a teen, I would like some help with my diet!

Quick background: I’m a 17 year old male, lean at 145 lbs, weight lift every other day, and I’m super into nutrition and fitness!

I have some questions about optimizing my diet:

1. Teens and occasional intermittent fasting?
2. Should I restrict protein once a week at my age?
3. What minimum amount of carbs should I make sure that I get per day if I work very hard at school and every other day a 45 min intense workout? I feel good slightly under 200g, but is this enough to support my body and brain at this age?
4. How important is rotating foods?
5. Is 40-55g of fiber every day too much? (these factor into my carbs)
6. Is up to 130g of fat every day okay?

I’m very in tune with my body: I’m carb sensitive, digestive sensitive, and so on. Eating very low carb all day and having a large carb dinner seems to be working for me, but is restricting carbs during the whole day and having a fairly low carb total (200 or less total: up to 50g of fiber and under 70g sugars) perfectly safe for a teenager?

If it helps, let me know if I should send you my daily diet.

Thanks so much 🙂


1. A skipped meal cause you’re late to class or have butterflies before a date or big game or final exam? Sure. Go for it. Don’t sweat it. But don’t do it on purpose. You’re still in the healthy growth phase where you’re extending bones and developing your brain and and autophagy — the “cleaning up” of discordant, harmful parts of cells promoted by fasting — is more important for older people.

2. No. If you’re not hungry for protein don’t it. But don’t force yourself.

3. I’d say around 200 grams is a good amount of carbs, if you’re feeling good. By all means, increase the carbs just as a trial to see if you feel even better and your gym/school performance improves. You’re obviously a curious guy and it might be fun and illuminating to experiment with more. Also, I wouldn’t count the fiber toward your carb count. Fiber’s good but doesn’t contribute to glucose load.

4. I think there’s value in rotating plant foods. Instead of eating spinach every day, you eat broccoli, kale, chard, bok choy, green beans, cauliflower, and spinach throughout the week. Instead of just eating blueberries, you eat blackberries, raspberries, bananas, pineapples, and blueberries. Rotating plant foods gives you access to a greater variety of antioxidant compounds. If there’s a danger in overdoing any single antioxidant, eating a variety will sidestep it. Otherwise, there’s nothing wrong with staple foods or a reliable, even “boring” meal plan. I often eat very similar things day in, day out.

5. If your digestion is adequate, large amounts of fiber from vegetables and other Primal sources will only be beneficial. You may have to scale back the fiber if you’re experiencing bloating, excessive and ill-timed flatulence, diarrhea and/or constipation, but if you’re happy with the toilet visits keep up the fiber. Make sure enough of it is fermentable stuff, things like Jerusalem artichokes, cold potatoes (resistant starch), green bananas, jicama, fruit, and other prebiotic fiber sources to keep your gut bacteria healthy and fed.

6. Absolutely. Fat’s an important nutrient, particularly for younger people. Keep it up if you feel good and you’re not gaining any weight.

Brandon, you sound like you’ve got a good head on your shoulders. If I could make one suggestion, it would be to relax a bit. I detect a lot of micromanagement in you. Some people are just wired like that and thrive by drilling down every last detail. That’s cool, if so. Do what works and what you enjoy. But don’t be afraid to relax and kick your feet up a bit, too.

You’re lean and active and intelligent. There’s no need to hamstring yourself with an overly strict approach to diet and life in general. Maintain your regimen as long as you enjoy it and genuinely wish to continue with it. Don’t impose arbitrary restrictions is all I’d recommend.

It’s a big world out there. You might end up really liking it.

Hi Mark,

Back in December I slipped on some ice and broke my leg in two places. I am just now getting rid of the second crutch and able to walk unaided. However, I am unable to run and the surgeon tells me it will be quite some time before I can.

Do you have a suggestion for what to do instead of sprinting for the 21 day challenge? Obviously, my options are limited for quick movements at the moment.

Your recommendations would be appreciated.


Do you have access to a pool? If you do, and you’re out of your cast (or have some way of waterproofing it), you can do some work in there. Stick to light swimming, mostly freestyle. Avoid frog kicks/breaststroke, as that could place weird stresses on the healing leg.

But don’t sprint, not yet. You can probably skip the sprinting. You should skip the sprinting. At this point, recovery from your injury is the most important thing. Pain free movement will help your recovery, but sprinting of any kind is too intense to risk re-injury or re-aggravation. You could be feeling great until you don’t and something goes terribly wrong.

Then you’re back to square one. And sprinting is even more out of the question.

If no pool is available, don’t sweat it. Just eat well, walk as much as you can comfortably, do some upper body strength training — which, if done at a quick enough pace, can be a sort of “sprint” or at least elicit similar metabolic effects — and get tons of sleep. Your job is to recover.

Okay: if you really need to sweat (a need which I totally understand; I hate sitting around when I’m injured), maybe something like seated battle ropes would work well. Those are surprisingly taxing.

Hi Mark and crew,

I live in Ventura County, and I was wondering if you have heard of The 3 Mules. As a horse person, I had heard about him – a man in is 60’s traveling up and down our state for decades, accompanied only by his pack mules, walking continually, sleeping and living outside full time. A few days ago, I happened to see him (and the mules) going to REI in Oxnard. All I could think was that here is a real live Grok. Coincidentally, I saw him the following day in Ventura (this time surrounded by police, as it is now apparently illegal to live a nomadic lifestyle and travel with mules …) Here is a humble, unassuming man that lives a life he believes in, day in and day out. (I can’t vouch for his diet, though). He has garnered over 30,000 FB followers. Pretty interesting story. FB: The 3 Mules.


Hey, neighbor. You’re right next door!

I love the 3 Mule story. The guy is clearly doing what he loves, and that’s about as healthy and happy as you can get. Lots of slow movement doesn’t hurt, either.

As for me, I love my life. I love having my wife and kids nearby. I like where I live. I don’t like to imagine not being able to go to the beach or the canyons or the mountains or the desert when I wanted, or go to a great farmer’s market for local meat and produce every Sunday, or use the salt water pool in my backyard, or roll around on the grass with my dogs, or hop on the slackline. I’m sure most people feel like that about where they live and whom they live with. We all started as hunter-gatherers, but most of us have a large amount of farmer blood in us, too. We’re a settled people, modern humans. Most of us like having roots.

Yet a piece of me understands why the mule guy is doing what he’s doing. The urge to roam, to get rid of all the extraneous possessions (which, let’s face it when you get down to it, is almost all of them), to hit the road, to forge your own road lies in everyone. Even if your idea of roaming is travel for two weeks once a year in Hawaii, that’s still the human propensity to wander and explore and discover new lands expressing itself.

Maybe if I was forty years younger. And maybe goats instead of mules. I’ve always liked goat dairy. If we’re getting really fantastical, though, I’m bringing along a gigantopithecus. Not as a pack animal, but a companion. Given enough time together, we’d develop a mutual linguistic understanding. He’d learn to understand English, and I’d come to understand his grunts, clicks, and snorts. A Chewbacca to my Han Solo.

That’s it for today, everyone. Thanks for reading and, as always, I’d appreciate your feedback and input in the comment section down below.

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

If you'd like to add an avatar to all of your comments click here!

46 thoughts on “Dear Mark: A New Whole Grain Study, Advice for a Teen, Broken Leg Sprints, and The 3 Mules”

Leave a Reply

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

  1. Woah, Mark thinks whole-grain is (technically) better than refined? I always assumed the simple carb load was less worrisome for someone who isn’t losing weight than the antinutrients in the bran. Also I used to eat a ton of whole grains and had serious constipation, so I’ve always viewed grain fiber as ‘bad fiber’.

    1. Then again it sounds like bran is the most nutritious part. Very curious.

      1. Yeah, I’m a little baffled as well. I know Mark has said white rice is preferable to brown rice as it’s, as he calls it, a “neutral grain”. Would think that same principle would apply to other grains but maybe there’s a factor I’m missing.

        1. I think it depends on the amount of amylase in your saliva that breaks down and helps digest carbs. Some people’s pancreas do not produce as much as others and they’ll have a harder time with wheat than others.

    2. I’m pretty sure he means whole grains are better for people who aren’t getting their nutrition from better sources. As in, it’s better to binge on whole wheat pasta than it is to eat only refined carbohydrates, but either method is still vastly inferior to getting your nutrients from eggs, meat, and vegetables.

    3. I don’t think he said that. He said that eating whole grains rather than refined could indicate lower consumption of processed junk food, which is what could really be causing the lower mortality cited.

      This is the problem with an observational study – it doesn’t establish any sort of causation, and as you can see, causation can be hard to tease out of data. Even if you get a lead, it’s easy to misinterpret, as one of us is doing here.

  2. I did seated arm-bike sprints when I broke my leg. Worked great and satisfied my need for some more intense exercise.

    1. Where did you use the arm bike? Are they common? I don’t think we have one at our Y . I have a broken tibia and fibula.

      1. I also had a broken tibia and fibula. I used the arm bike at the Life Time Fitness club I belong to. That was also when I learned to bench press – didn’t need to be on my feet 🙂

      2. I know this is way past the post date but may help someone currently in same situation. I also have broken tibia/fibula combo and am using my bicycle on a trainer with one leg, good leg obviously! Trainers can be had for 40$.

  3. Totally agree about giving the pool a try if you have access to one for some cardio while rehabbing an injury. As someone who has dislocated their kneecap playing basketball and messed up my shoulder from snowboarding, the constant fluid resistance of the water allowed me to get my heart rate up without further stressing my joints or risk making things worse.

  4. About the grain thing: you ARE aware that there’s a huge peer-review scandal going on, right? What a perfect time to publish a so-called “study” that’s really a PR campaign sales pitch for grains!

    1. Can you give me a link about the peer review scandal? Soon we will all just have to use our own experience to make decisions.

      1. Here is a link to a WaPo article about the current peer review scandal:

        Don’t give up on science! Continue to do your n=1 experiments, of course, but consider broader evidence, too. Most of the recent problems are coming out of Chinese labs, where pressure to publish and get high-impact results is even greater than it is here in the U.S.
        When peer review works the way it is supposed to (and it usually does) it is still an excellent way to separate the wheat from the chaff (although we primal peeps are not interested in either!).

  5. With regard to popular interpretation of the whole grain study, I was trying to remember what kind of formal propositional fallacy that is. But I don’t think there is one. I’m going to call it “affirming the unrelated”.

    p = Whole grain decreases mortality compared to refined.
    q = Whole grain is beneficial over refined.
    z = Low-carb is beneficial.

    p -> q
    therefor not z

    (Reads as: “P implies Q. P is affirmed. Therefor not Z”)

    So yeah, if that fallacy formally exists then school never taught it to me. Probably because it is extremely asinine.

    1. I think it’s two fallacies in a row.
      if r = whole grains are beneficial
      the first fallacy would be q r, false equivalence hinging on the idea that grains are healthy.
      the second fallacy would be r -> !z, or a strawman which falsely tries to substitute “some carbs are healthy” with “avoiding carbs is unhealthy”

      Anyone can correct me, my logic is rusty.

      1. *This post must be read in the voice of the snottiest internet anon you can imagine. It is not my intention, but I feel it is coming off that way.*

        So, you’ve made a similar mistake. You’re attempting to preempt the preposition by placing generic grain consumption on some sort of “health number line”, and by doing so have gone out of scope of the question.

        The question is, “Does the consumption of whole grains confer improved mortality rates over the consumption of refined grains?”. This is irrespective of the absolute health of such an eating pattern.

        As an analogy, you can ask, “Does the smoking of cigars confer improved mortality rates over the smoking of cigarettes?”. Smoking at all may not be healthy for you, but that is not what is being asked. We’re asking which of the two may be better/worse irrespective of their absolute effect on health.

        A strawman fallacy is intentionally misrepresenting the view point of your opponent in a reductio ad absurdum manner in order to discredit them. So, I don’t think r -> !z is a strawman, but I think I get what you were going for.

        1. I don’t see any way, proper or flawed, to go from ‘whole grain is beneficial over refined’ to ‘low carb is not beneficial’ without introducing an intermediate step or two. The thoughts are, simply speaking, completely unrelated.

  6. I saw an article on CNN last week that advocated eating cereal every day for the fiber. Luckily it made the distinction between Sugar Smacks and Fiber One, but it still encouraged the consumption of breakfast cereal for a longer life. It was backed up by Harvard.

  7. I had never read any shape magazine articles, but I just did and they are obsurd, maybe as bad as fitday. Nothing like twisting a study to suit your agenda, or clinging blindly to CW. Plus, think of all of those other confounders in the study that aren’t even mentioned!

  8. So much wrong with that grain/longevity story.
    First, one of the basic tenants of the scientific method is, “are the results repeatable by other scientists?” One study tells you nothing.
    Secondly, correlation is not proof of causation. Because two things appear to occur in tadem, that is not proof that one causes the other. I’m reminded of the parable of thecat seen walking past a hole in a fence. First the head appears, then moments later the tail. Conclusion 1: the head is pulling the tail. Conclusion 2. The tail is pushing the tail. The problem, of course, is that the observer can’t see the feet.
    There are now babies dying of preventable diseases because another flawed, unrepeatable study was glommed onto as proof.

    One the mule topic: Funny thing. yesterday on Palm Sunday, I heard another story about a guy who wandered around the countryside and then rode into the city on a mule. The authorities didn’t like him either.

  9. In the interest of cutting to the chase (after reading the grain comments here), they aren’t necessarily poison. A lot of people do well on a diet that includes grains, such as a bowl of oatmeal for breakfast or a whole-grain sandwich for lunch. Often they are thin and healthy with no medical problems. I have no quarrel with those people. They are doing what works for them, and that’s what all of us need to do.

    Thing is, grains don’t work for everyone. Many of us don’t tolerate grain products very well, if at all. They can cause or contribute to all sorts of health issues; they are often combined with sugars and various chemicals and preservatives, which makes them considerably less than a great idea; and they can definitely be fattening. I mostly avoid grains for these reasons, regardless of what this or that study might claim. I get all the carb nutrients I need from fruit and veggies. Grain carbs don’t really fit in with the way I prefer to eat.

  10. We found that eating twinkles and drinking coke had less mortality than total starvation. So we’ve concluded that twinkies and coke combined somehow form a super health food.

  11. Haha if I were going to be ‘nomadic’ I would want to have some goats with me too!

  12. I’m really digging the Gigantopithecus idea. But would I have to train him to tear people’s arms out of their sockets when he loses or would he do that naturally? Because, that’s kind of a deal breaker.

    I’ve long wanted to rid myself of all possessions and wander the countryside with my dogs and a horse. I can only imagine the legal entanglements that would inevitably occur. Totally worth it, though.

  13. We are currently living on the road, not mules, but our small motorhome, travelling England looking for a new place to settle, we left Scotland November last year.

    There is something quite addictive about changing the scenery regularly although another English winter would probably sort that out!

  14. Knowing how you suggest we play instead of exercise in some cases, your comment about swinging ropes took me back to childhood when we played double dutch jump rope. Two of us facing each other with one end each of two ropes in our hands swinging opposite directions so the jumper had to jump them alternately. We never thought of it as “exercise.” 🙂

    As an adult my favorite exercise was square dancing which is basically walking to music for a couple hours with a few arm movements thrown in.

  15. The mule trek would be a great way to explore Baja Mexico. Something like Ensenada to La Paz. The authorities and/or bandidtos down there would see you as being absolutely nuts and would leave you alone. The people off the beaten track would reveal how kind and wonderful rural Mexico can be. Perhaps the concrete jungle is not the right place for a mule that may have a tough time making a court appearance for trespassing.

  16. I broke two bones in my leg 4 weeks ago. Right after the new online 21 Day Primal Blueprint Challenge. In fact I was into a new 3 week program with the Lamberts when I did it.
    And what I really miss are sprints! So I feel the questioner’s pain.
    There are some good upper body cardio vids like Laurel House’s and I roll around on the bed with my foot off the edge, doing “superman, banana” a la P90x sometimes. But I found strength training was less tiring for a healing person. So probs just going to do seated body rows with band, knee push-ups and planks, etc

  17. “I wouldn’t count the fiber towards your carb count.”

    If we are trying to limit carbs to 50g a day for weight loss, does this mean we should not count the fiber? Or is this just because he is a teenager?

    1. I don’t want to speak for Mark as he probably addresses this in some previous post but, for the sake of brevity, I will say that he meant ESPECIALLY since he’s a teenager.

  18. Thanks for good advice to Brandon – especially the ‘relax’ part! As a recovering disordered eating parent of a 15 year old boy, I struggle with giving my son sound advice without lecturing and freaking out over tiny details (and allowing for that random bag of chips that’s just going to happen right now). Thanks so much to you and the worker bees!!

  19. I don’t know about the farting business.

    I don’t have excessive gas when I eat a wide variety of raw/cooked vegetables. However, my lunch bowl is chopped raw carrot, celery, sunchoke, and jicama. The gas is substantial and regular, like clockwork, a few hours after the meal. It doesn’t stink, so I don’t care.

    My research into the gut microbiota always comes back to the same thing…farting is fermenting. If you want the good guys to ferment, if you want to produce the short-chain fatty acids, I think you have to fart?

    There are many accounts of people “adjusting” to foods like Jerusalem artichokes. One theory, espoused in the comments section, is that other microbes consume the gas produced from inulin fermentation. While that does happen, I’ve yet to see convincing evidence that you can cultivate a biodiversity that eliminates gas. In fact, my experience is the opposite. If I go away on vacation, and then return to my beloved lunch bowl of fermentable fiber, it usually takes a few days to ramp back up to full production.

    Are you saying you can eat my lunch bowl every day and not fart?

    Beyond the lunch bowl, I practically live off of FODMAPs in terms of mass-of-food. If I skip the lunch bowl, but continue with massive amounts of FODMAPs, I barely fart. Not irregular at all, no other signs of indigestion.

    Everybody is different, so who knows?

    The microbiota is still a relatively nascent area of research. What I read all leads me back to…

    Farting = Fermenting (in a healthy gut there is “healthy” farting)

    It seems like healthy farting gets a bad rap around here. It’s kind of like the body-image debate. There’s nothing attractive about farting, but that’s largely perception. If it turned out that farting after eating raw sunchokes was extremely healthy, would you care? I’m telling you, it’s clean burning gas – depending on what kind of other fuel you put on the fire. It’s like a little motor-in-your-pants for an hour or so, sort of propels you around the room, with no one the wiser.

    Lot of anti-fartites out there.

    1. At first I thought you were full of hot air, but then it all started making perfect ‘scents’…fart on brother!

    2. Sunchoke is, without a doubt, the most fart-inducing veggie out there. Raw or cooked, they’re true air-biscuit manufacturers. The best way to eat them is with a large dog nearby… y’know, so you can blame the dog…

  20. How many of us do what we love? I assume few…
    However, there is a reminder and beauty in The 3 Mules story…
    If you really want to, you can do it, period.

  21. I disagree that whole grains are better nutrition, they have way more lectins which rip up my guts something fierce, i’m probably not the only one that responds that way. i avoid grains 99% of the time, including oats and rice and corn and millet. When I do indulge i choose organic white flour products or make it myself and i only eat a small amount. i can get away with it if I do it only rarely. The gut response is only one reason i avoid grains, i eat primal because i thrive on a low carb diet and i have tons of energy and live a very different life from most other 60 somethings I know. That JAMA article is a hoot, i’ll read it again in 60 years.