Dear Mark: Sun Beds, Skipping Breakfast, Cooking with Essential Oils, and Glycerol

It’s Monday, which means it’s time for another round of Dear Mark questions and answers. This week I’m answering four reader inquiries. First, I discuss the suitability of tanning beds, and try to give the best answer I can muster given the lack of hard evidence either way. Next, I cover whether or not a guy should definitely eat breakfast. Dr. Jack Kruse’s leptin protocol, which prescribes eating a high protein breakfast upon waking, is getting pretty popular and having some incredible results, but is it necessary for everyone? Then I field a question about cooking with essential oils. They may not be the powerful healing agents promised by aromatherapy, but can they replace dry and fresh herbs and spices? Looks like it (maybe). And then I give a quick response about glycerol-bound stevia versus powdered stevia. All in all, a nice little selection of questions, I think.

Let’s dig in:


I live in Ontario and love spending time in the sun (as well as following all that is contained in your regiment). From October to May, there is little option available. I take your recommended vitamin D supplements, and also like to stay looking ‘tanned’ during the winter months and use indoor tanning beds once or twice a week. Do you feel this is safe? It keeps me feeling much better than if I do not use the tanning beds.


Recent epidemiological research (PDF) links tanning bed usage to malignant (read: bad) melanoma, but it’s, well, epidemiological. Correlative. For a nice writeup on the study, check out John Durant’s take. Of course, this particular correlation has a pretty sound potential mechanism of action – we know that excessive amounts of ultraviolet rays definitely can damage the skin and precipitate the formation of cancers like melanoma. That’s not controversial in the least.

In theory, a tanning bed could be useful and even beneficial. If you modulated the intensity of the bulbs and the ratio of UVB to UVA to emulate or at least closely resemble the sun’s rays, and you understood that pressing your skin right up against the bulbs isn’t exactly analogous to laying out in the late morning sun, I see no issue with using it. But you’re not running the salon. The salon owner is, and unless you can obtain absolutely irrefutable evidence that the salon owner is a student of UV and vitamin D metabolism science, I would be wary. If they have signed photos of the cast of Jersey Shore up on the walls, I would be wary. If they’re trying to sell you on a tanning package to turn you dark orange with visits thrice a week, I’d be wary. If they balk at your insistence on naturally attainable doses and ratios and intensities and act miffed because you want to limit your time under the lamps, I’d be wary. They’re probably not interested in giving you a lovely, relaxing day at the beach. They want you in and out, fast, to make room for the next customer. If corners are cut, if the intensity is magnified beyond what you’d receive sitting in the sun, if you’re sitting too close to the bulbs for too long, you’re exposing yourself to an evolutionary novel dosage of a known stressor. That could be okay, but it might not.

And I wouldn’t take my chances.

Unfortunately, there’s very little solid data out there on the safety of sunbeds that isn’t tainted with kneejerk reactions from dermatologists (“it’ll give you cancer!”) or from sunbed manufacturers. I know Joe Mercola has a sunbed, but I’m not sure if it’s legit. It very well could be, but it remains to be seen. This is probably worth a further look later down the line. Be sure to check out That Paleo Guy’s (Jamie) last couple posts on sun science. Very helpful stuff.

Remember what I wrote during last week’s “Dear Mark” – heed your ancestral homeland’s climate. If your distant ancestors weren’t sporting tans during winter, you may be okay a little paler for a few months out of the year. From what you’ve said, it sounds like you’re using sunbeds very responsibly. If you’re going to keep using them, maybe keep it to once a week, and don’t chase the ultra tan look. Go for a little color instead. Depending on your melanin, you can actually make a lot of vitamin D (and, presumably, all the other compounds our bodies make in response to UVB) before you tan.

The poison’s in the dose. And when the toxic dose is unknown or as-yet unquantifiable, you take small, cautious nibbles at the thing (if at all).

Hello Mark,

I am never hungry in the morning. I’d rather break my fast about midday with a big lunch and a big dinner in the evening (essentially 2 meals a day) and this suits me. Is this a problem, not having breakfast, as Jack Kruse talks about leptin resistance and the fact that you need 50-75 g of protein within 30 minutes of waking up. I cannot do that. I just am not hungry in the morning. What are your thoughts on this? Am I ok to stick to what I am doing, or do I need to force feed that amount of protein first thing in the morning?


Are you making progress? If you’re still moving forward and hitting goals and everything is proceeding as desired, I see no reason to mix things up just for the sake of mixing things up.

Are you feeling good? If you’re overall feeling satisfied with the current state of your physiology, keep doing what you’re doing.

How’s your energy? If you’re enjoying a smooth, constant level of energy without the need for regular infusions of caffeine, that’s a good sign that your current routine is working.

Are you at your goal weight, or are you trying to lose weight and having little success? If you’re stalled or gaining, you might try giving breakfast a go.

Never let someone else’s prescription for optimal health and rapid fat loss control your life – whether it’s mine or anyone else’s – if it isn’t producing results. Don’t stick things out if they haven’t been working for several months, but on the same token don’t go rushing around trying out every new protocol just because. As I understand it, Dr. Kruse’s leptin resistance protocol is intended for folks who are leptin resistant, for people who can’t really trust the satiety and hunger signals their bodies are sending. You may be. But if you’re not, I would say (and I believe Jack would, too) that skipping breakfast is fine as long as it doesn’t negatively impact your life, your weight, your health, or your progress.

If you’re leaning out, have leaned out, regained your health, and/or all other health markers are in good shape or trending that way, and if you’re still not hungry in the mornings, I’d say you can probably trust what your body is telling you and maintain the fasting. On the other hand, I say give it a shot if you think your current eating schedule isn’t doing you any favors.

Making breakfast mandatory can definitely work, but so can plans that make skipping breakfast mandatory. There is no one way. People have had success with both methods.

I understand that clove essential oil has an ORAC score of over 10 million (the highest of any fruit or herb). What are your thoughts on essential oils, especially clove? Given its high ORAC score, is it safe to assume that it contains potent anti-inflammatory/anti-aging properties?


While I’ve written about the inconsistent evidence of any benefits to using essential oils in aromatherapy, I’ve never actually considered using the stuff in cooking. Your question really intrigued me, because it occurred to me that in a lot of the studies that I cite in my various herb and spice posts, the researchers often use essential oils of the herb or spice rather than the herb or spice itself to test the various compounds with antioxidant and/or medicinal attributes. Since they’re using the oil rather than the herb, all the “good stuff” – the active ingredients, if you will – should be found in the oil.

And I guess that’s why they call it an essential oil – it holds the essence that defines and truly makes the herb or spice what it is. If that’s true, then couldn’t we use the essential oil in our cooking instead of or in addition to the herbs or spices themselves?

Food producers already use essential oils of things like rosemary, thyme, clove, and sage to preserve the oxidative stability of fats in processed foods, because those oils are highly bioactive and confer all of the benefits of the dry or fresh herb (PDF). As long as the essential oil is “food grade” and it’s from a plant that people actually eat (I would strongly recommend against using oil of eucalyptus in your cooking, for example, mostly because it’s toxic but also because it tastes terrible), I see no problem with experimenting. Start with single drops applied directly to the cooking fat of your choice; don’t treat essential oils like condiments. It’s not sriracha. A rosemary oil applied to an olive oil, perhaps, or a drop of cinnamon oil administered to a pot of coffee? The possibilities are myriad.

Before you go crazy, make sure the essential oil you’re considering is food grade and check the toxicity levels. This Excel doc (Excel) from 2009 is a handy comprehensive guide to toxicity levels for most essential oils.

Possible sources for food grade oils: NOW Foods (available on Amazon) and Aftelier Chef’s Essences.

Hi Mark,

Is there any difference between glycerine Stevia and the powdered kind? It tastes so much better, but I want to make sure it’s ok since I add it to my 3 iced coffees per day.


Glycerine in your stevia is fine. It’s another word for glycerol, which is a naturally occurring substance (a polyol, a type of alcohol) that forms the structural backbone of all triglycerides (hence “-glyceride”). Most animal and vegetable fats, then, contain glycerine. In pharmaceuticals and consumables, glycerine is used as a carrier and even a sweetener (it’s slightly sweet). It also holds moisture well – endurance athletes sometimes utilize it to retain hydration – so adding glycerol to low-carb junk food can make it stay moist and “delicious.” That’s why you’ll often find it in protein and energy bars.

At any rate, it’s impossible to avoid glycerine. We get it when we eat dietary fat and when we burn stored body fat for energy. And even though glycerine is classified as a carbohydrate, and a teaspoon of it contains about 27 calories, it follows a unique metabolic pathway. Nothing to worry about if used as a carrier for stevia.

That’s it for this week, boys and girls. Keep ’em coming and I’ll do my best to get to them. Thanks for reading!

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 more than three decades 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 flavorful and delicious kitchen staples crafted with premium ingredients like avocado oil. With over 70 condiments, sauces, oils, and dressings in their lineup, Primal Kitchen makes it easy to prep mouthwatering meals that fit into your lifestyle.

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