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.

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