Dear Mark: More of Your Challenge Questions Answered

Multi-ethinic arms outstretched to ask questions.For today’s edition of Dear Mark, I’m answering 11 questions. I answer questions about nutrient deficiencies and tremors, breastfeeding on the 21-Day Primal Blueprint Challenge, cheating without apparent consequences, sun exposure without vitamin D, maintaining insulin sensitivity, going high protein, recovering from a labral tear, going 90/10 vs. 80/20, black beans vs. potatoes, why I chose to live in Malibu, and recovering minerals lost to glycogen depletion.

Let’s go:

Hi Mark, I’ve been 80/20 primal since January 2012 and early in 2015 I developed a tremor that makes it difficult to do small motor tasks like writing, peeling eggs, lifting my fork to my mouth, etc. Other than this my overall health is good. My chiropractor thinks I might be missing some vital nutrients that may have brought this on, but I disagree with him, because of what I eat and more importantly what I don’t eat. I don’t see how I could be missing nutrients with liver, eggs, meat, fish, green vegetables, collagen, good fats, etc. in my diet, and no grain, sugar, or veg oils. I have tried to fix this for almost two years with primal eating, sleeping, and exercising to no avail and the neurologists don’t have any answers for me either, they just give it different names. My MRI’s don’t show any brain damage or degeneration, thank goodness. Can you possibly shed some light on this, do you think I AM missing something, where have I gone wrong? I would appreciate any help or advice you might have. Thanks so much.

This isn’t medical advice, because this sounds like it could be a serious medical issue. But what keeps springing to mind is vitamin B12 deficiency, which commonly presents with tremors, loss of motor function, degraded balance, and numbness in the extremities.

According to Chris Kresser, many otherwise healthy patients eating a nutrient-dense Primal-type diet rich in meat (the best source of vitamin B12) still end up deficient in B12. It may be an absorption issue.

He’s got a free eBook on B12 deficiency, actually. It’s probably worth checking out.

Hi! Really interested in the 21 day challenge, but is it safe for someone that is breastfeeding?

Absolutely, with some extra precautions:

  • Don’t go too low on carbs. Many women find they need additional carbohydrates to produce enough milk.
  • Don’t go too low in calories. Going too low in calories will tank your milk supply. And if it doesn’t, you’ll draw on your bodily reserves of various nutrients to produce the milk. Either result is bad.
  • You need to eat enough calcium or else you’ll take it from your bones and teeth. If dairy doesn’t bother you, eat it. It’s the best source of calcium around. Other options include blackstrap molasses and bone-in sardines and other small fish. Leafy greens can have a decent amount, but I wouldn’t rely on broccoli for calcium.

I’ve noticed that having some gluten free carbs on occasion has little effect on bloating and feeling bad as well as minimal effect on weight. E.g.- corn tortillas if I’m having fajitas or a gluten free beer. This is generally in the context of a cheat meal, of course, but what are your thoughts, Mark? Fine as part of my 20% or still something to be avoided as a rule?

Totally fine, especially in the context of a cheat meal. That’s how you do 80/20: cheating while minimizing the consequences.

Hi Mark,
How much skin should I expose when I do the 15 minutes of direct sun exposure each day? I live in Wyoming and it’s cold outside, so the less I need to expose the better.

Reader Coccinelle answered this perfectly:

Are you talking about right now in January? Because there is a good chance you won’t make any vitamin D at all even while naked in the sun for one hour.

“In order for the sun to stimulate your Vitamin D production, the sun needs to be at a minimum of about 50 degrees, or greater, above the horizon (90% would be directly overhead). Ideally, the sun should be as close to overhead as possible; the closer to overhead it is, the greater its potential for stimulating Vitamin D production (and the less time you have to be in the sun to produce a given amount of Vitamin D).

A good way to test if the sun is about 50 degrees above the horizon, or higher, is that your shadow should be slightly shorter than you are tall. If the shadow cast by your body is the same length, or longer, than your height you will not produce Vitamin D–even while your skin is exposed to direct sunlight. And this is under ideal conditions: clear skies without cloud cover or pollution.”

Excerpt from here:

To that I’d also add that getting outside into bright natural light remains important even if you’re not making vitamin D. Light exposure, particularly in the first half of the day, helps set your circadian rhythm. You’ll probably find that getting sunlight in the morning and afternoon helps you sleep better at night.

All light matters.

With supplements, spices, foods, and other interventions (like walking for 15 minutes after eating) that increase insulin sensitivity (or really anything listed in this article: )

Are there any lasting chronic effects from these interventions, or all they all more acute and short term? Will taking cinnamon and eating a salad with apple cider vinegar everyday change the environment in the cells they effect (like how properly training will result in mitochondrial biogenesis)?

I hope what I’m trying to convey is getting through clearly.

I hear you.

The thing about human physiology is that it’s malleable. Just like training can grow muscle cells and build entirely new mitochondria, not training can shrink muscle cells and reduce the number of mitochondria we have. The same applies to insulin sensitivity/resistance.

To maintain insulin sensitivity, you simply must keep the “interventions” coming. You can’t really ever stop training, moving, eating adequate magnesium, sleeping well, or eating cinnamon. Cinnamon has an acute effect on insulin sensitivity, but it doesn’t last. You gotta keep sprinkling it in your coffee.

This is a good thing. It means you can’t ever rest on your laurels. You have to stay vigilant. Do it long enough, though, and it’ll become second nature. You’ll get to the point that you can’t not move, sleep, and eat well.

So far the Challenge has been going well, but last night I still felt hungry and feel it might be because I didn’t get enough calories from fat. For someone who has trouble increasing the amount of fat they eat, especially without a gallbladder, do you think a higher protein primal diet is possible?

Absolutely. Protein tends to be the most satiating macronutrient (more than either fat or carbs), so eating more protein will probably take care of your hunger.

Also check out what I’ve already written on going Primal without a gallbladder.

I’m three weeks out now from shoulder surgery — labral tear repair (three dislocations will do that to you). I’ve been eating primally (80% ish over the holidays, 100% since the first of the year), have been eating varied sources of collagen/gelatin like it is my job. I have a great physical therapist, and am participating in the 21-day challenge, so overall doing a pretty darn good job in all the primal lifestyle categories.

My question is — am I missing anything that could further facilitate healing? I’m prepared for the predicted 4-6 month full recovery time…but would love to aim for the 4 month end of that range. I miss burpees, believe it or not.

Add some vitamin C in with your collagen. An hour before you’re about to do your physical therapy exercises (which you are doing, right?), consume 15 grams of collagen/gelatin and 200-300 mg of vitamin C. That’s the protocol a recent study used to increase exercise-induced collagen synthesis.

As for burpees, make sure you do any future reps with extreme vigilance. Do not get lazy. Don’t let your technique lapse on rep 20+. Consider some of the burpee alternatives I wrote about awhile back.

In fact, be careful with pushing movements. Move slowly and increase progress gradually. Don’t push it.

Stay 100% Primal. Avoid cheating as much as possible. Maintain an anti-inflammatory physiological environment to promote healing.

Hi Mark, I’ve been successfully adhering to the 80/20 primal eating guidelines. I was wondering if, for self-improvement’s sake, I should aim for a higher compliance ratio like 90/10, or should I intentionally remain at 80/20 to ensure I avoid potential pitfalls? Thanks!

If you’re happy with your progress or maintenance, stay 80/20.

If not, use this month to try being a little more strict. See how it affects you.

Everything’s a choice. Nothing is final. You can always go back to your previous trajectory. Experiment always.

Good day Mark! If one wanted felt like they needed some additional carbs, would soaked and rinsed black beans a better option than a potato. Considering black beans are nutritionally superior to potatoes. This is the great debate between my wife and I.

Both have their advantages.

I’d say soaked and rinsed black beans beat a basic baked potato. As you say, black beans do have more nutrients than the potato on paper (the potato’s no slouch, though).

But a cooked and cooled potato (baked/boiled then kept in the fridge for 12 hours) is a different story. It contains ample amounts of resistant starch, one of the most important fermentable substrates we can give our gut bacteria. Black beans are also rich in prebiotic fiber, but they don’t contain as much resistant starch.

I’d say alternate between both. No reason you have to choose one or the other.

I have a question mostly for mark. Why did you choose to live in Malibu? Isn’t the traffic there horrible? I’m planning my next move so wondered if it’s possible to live without a car.
More generally, how important is it for everyone to rely on active transportation in their lives?

Traffic isn’t great along the Pacific Coast Highway (PCH), but I’m not a regular commuter so it’s not a big deal. You probably do need a car, however. LA in general is not a walking city.

I like Malibu because the air quality is quite good, especially for Los Angeles. It avoids most of the awful heat inland Socal areas can get. And most importantly, I’m close to the beach and the mountain trails.

Active transportation is the ideal mode of getting around. I wish I could walk more places. But it is what it is, and I live in the most car-dependent area of the country. You do what you can, which is why people have treadmills and drive several miles to get to a trail or track. You work with the hand reality deals.

Hi Mark,

On my first night of the 21-day challenge, I had to get up to go to the bathroom numerous times. A friend who has followed you for some time said this is probably OK since my body is burning up the glycogen stores, it will produce a lot of water. Your thoughts on supplementing a little sodium in my diet, or other minerals that I might be losing in this process?


  • Try a glass of lemon water with sea salt in the morning (sodium and potassium).
  • Drink sparkling mineral water instead of regular water (magnesium and calcium and other minerals).
  • Eat plenty of produce (potassium).
  • Eat blackstrap molasses (potassium, magnesium, calcium).
  • Salt your food to taste (don’t be scared if you do a couple extra shakes).

That’s it for today, folks.

There are still questions I haven’t answered, and I’ll pick those up in Mondays to come. So, fear not if I haven’t gotten to yours yet. Take care and thanks for reading.

TAGS:  dear mark

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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