Mark’s Daily Apple is the go-to destination to learn how to lead a healthy Primal life in this hectic modern world. A completely irreverent, bold take on the latest in health, diet, fitness and supplement news. Daily health tips and breaking information. Recipes, fitness and health coaching.
My staff and I are quite close. Things stay busy these days, so there isn’t a lot of downtime, but I’ve worked with some of these folks for over a decade. We don’t discuss every grisly detail of our lives with each other. But we do share. We care about each other.
So when one of the Worker Bees mentioned he was having some potentially serious medical issues, I asked for details. Turns out he went to his doctor for a hard lump on his throat that was getting progressively bigger. Initial pokes and prods were inconclusive. An MRI led to a biopsy, which led to an email in the middle of the afternoon with the results and a hell of an opener: “This may be a cancer.” May helped. It wasn’t a sure thing yet.
For the next couple months, he continued getting tests to confirm one way or the other. A full body scan confirmed hypermetabolic activity in the lump, just like an active cancer would show. No other tissues showed up on the scan, meaning nothing had spread or originated elsewhere. No cancer confirmation, but his doctors were definitely leaning in that direction. He had meetings at the cancer center, filled out end-of-life directives, got a special parking pass. It was intense.
It wasn’t supposed to happen to a man like this. A wife, two kids, dogs, chickens, a new house, a job working in the health, fitness, and nutrition industry. Mid 30s. Fit, eats well, a strong foundation in Primal health principles. But happening it was.
Here’s what he said to me:
“Whatever happens, this has changed my perception of reality for the better (I think). I live in a different world now, rich with meaning and love and powerful emotions. It’s remarkable.”
As he put it, when you think you’re dying, the nonsense you’ve been perpetuating falls away to reveal the essentials. It just happens on its own, and you get a glimpse of what really living entails.
Hugging your kids. Kissing your wife. A stroll after dinner to watch the sun dip below the horizon. A hawk soaring overhead. All things you’ve done and watched before, only now it’s different. Everything becomes imminent. Your concepts of the world and space-time condense. There’s less time now, but instead of getting frantic about it, you slow down and savor the moments. You’re present. Things that might have ruined your day or mood just roll off your back.
He saw it as a rare gift, and I have to agree. For all intents and purposes, he was dying (he wasn’t, but his nervous system didn’t know the difference). He got to make all the amends, undergo the self-realization, think about all the dreams and regrets he had accumulated or almost accumulated, and view things he took for granted in a new light. He got to prepare for death.
And then, he got good news. Exploratory surgery with an immediate biopsy right there in the operating room revealed that it wasn’t cancer. It was a cyst. They removed it. He went home, none the worse for wear.
The trickiest part of his whole experience has been figuring out how to keep it fresh in his heart and mind. How can he take what originated as a visceral response to the perceived threat of dying young and make it established policy? Turn it into wisdom that persists even when the threat has gone? The lump’s gone, and it never actually was a real threat. Will the insights remain?
That’s the eternal battle raging inside us, isn’t it?
We have these massive epiphanies triggered by events large and small. They change us, make us see the world from a different perspective. The prospect of random cancer helped the Worker Bee realize what he was taking for granted and glossing over. But when the direct effects of the trigger wane, we tend to let ourselves go. We get sloppy, complacent, and return to our previous incarnation.
Figuring this out seems like the key to happiness, success, meaning, world peace, and everything else we claim to hold dear. If we could get a handle on that slippery aspect of human psychology—the tendency to let learned wisdom flit away because the initial trigger resolves—there’d be no limit to what we could do as individuals and a species.
As we near the halfway mark of 2018, I want you all to ruminate on this matter.
How can we keep the spark of learned wisdom alive?
How can we turn tragedies into sustained improvements?
Better yet, how can we turn the tragedies of others into fuel for our own enduring improvements and realizations?
Let me know what you think, what you’ve learned down below. We all have stories like this. Candid details welcome and encouraged.
Thanks for reading, everyone. Take care, be well, and next time you hug a loved one, feel that hug for the miracle it is.
All-meat diets are growing in popularity. There are the cryptocurrency carnivores. There’s the daughter of the ascendant Jordan B. Peterson, Mikhaila Peterson, who’s using a carnivorous diet to stave off a severe autoimmune disease that almost killed her as a child. The most prominent carnivore these days, Dr. Shawn Baker (who appears to eat only grilled ribeyes (at home) and burger patties (on the go), recently appeared on the Joe Rogan Experience and Robb Wolf’s podcast, and is always breaking world records on the rower. Tons of other folks are eating steak and little else—and loving it. There are Facebook groups and subreddits and Twitter subcultures devoted to carnivorous dieting.
What do I think?
I’m no carnivore. I love my Big Ass Salads, my avocados, my steamed broccoli dipped in butter. My blackberries, blueberries, raspberries, and strawberries. My spoonful of coconut butter.
Yet, I get the appeal.
We’ve been eating meat for three million years. Its caloric-and-nutrient density allowed us to dispense with the large guts needed to digest fibrous plant matter and build massive, energy-hogging brains. There isn’t a traditional culture on Earth that wholly abstains or abstained from animal products. Nearly every human being who ever lived ate meat whenever he or she could get it.
Thus, meat appears to be the “baseline food” for humans.If you look past the cultural conditioning that tries to convince us that meat will give us heart disease, cancer, and diabetes, meat looks pretty damn good as a place to start.
The question is if it’s where we should stay exclusively….
All this said, I’m skeptical about the “steak and water” or “ground beef and water” diets of modern carnivory. Let me explain….
A Few Key Arguments For It (and My Feedback)
“In its natural state, meat is relatively safe as far as toxins go.”
Animals can run and bite and claw and fly to get away from predators; most don’t need to employ any chemical warfare that causes problems when you eat the meat. Sure, allergies and intolerances can arise, like if you get bitten by the Lone Star tick and pick up a red meat allergy, but those are quite rare.
“Whereas plants’ phytonutrients are pesticides.”
This is technically true. They are toxins the plant produces to dissuade consumption by predators—toxins that the plants manufacture to maim, poison, kill, or even just make life uncomfortable for the animals who eat it.
But just as we can do with many other “harmful” inputs, we tend to treat plant phytonutrients as hormetic stressors that make us stronger, healthier, and more robust.
There’s an upper limit, of course. And many of the phytonutrients have been primarily applied either to populations eating normal omnivorous, often downright unhealthy diets or to unhealthy subjects trying to improve a disease marker. As I’ve said before, there aren’t any real studies in healthy human carnivores, so we don’t know one way or the other whether the promising results of the extant studies apply to people eating only animal products.
“Meat nutrients are highly bioavailable.”
The protein has all the amino acids we need to live and thrive. We readily absorb and utilize the vitamins and minerals in meat; they already come in “animal form,” requiring little to no conversion before we can start incorporating them into our physiology. Plant nutrients usually undergo a conversion process before humans can utilize them, and not every human has the same conversion capacity.
Some of those essential and/or helpful nutrients only occur in meat, like creatine, carnosine, vitamin B12. There’s literally no realistic way to obtain them without relying on supplementation, which didn’t exist until the last hundred years.
“Nutrient requirement studies don’t apply to us.”
I could see that. They haven’t tested the requirements for selenium, magnesium, and iodine on a zero-carb carnivorous diet. Do they go down? Can you therefore get by and thrive on lower intakes—the low levels found in muscle meat?
It’s a tough call.
It hasn’t been empirically tested. That’s true. It largely hasn’t undergone a series of RCTs. You can’t pull up a Cochrane meta-analysis of carnivore studies. All we really have are anecdotes.
I’m not disregarding the power or relevance of anecdotes and testimonials. Those are real. They’re not all suffering from a mass delusion. They’re not all lying. Peer-reviewed? No. Admissible in a scientific paper? Not unless you call it a case study. When you’re there in the room with someone pouring their heart out because something you wrote helped them drop 50 pounds and reclaim their lives, you don’t go “Yeah, but where are the clinical trials?” At some point, the weight of anecdotes adds up to something substantial, something suggestive. And hey, if it’s working for you, there’s no arguing that.
But I can’t point to anything solid and totally objective in the research. Not yet anyway.
Still, any time you embark on a historically unprecedented way of eating, whether it’s pure muscle meat carnivore or vegan, you should be a little more careful about what you think you know.
What Do We Know About Carnivory in Human History?
We don’t know if there have been any purely carnivorous human cultures. We haven’t found any yet, and you can’t prove a negative, so I won’t say “there were none.”
In all the best candidates so far, though, plants sneak into the diets. The Inuit actually utilized a wide variety of plant foods including berries, sea vegetables, lichens, and rhizomes. They made tea from pine needles, which are high in vitamin C and polyphenols. The Sami of Finland, who primarily live off a low-carb, high-fat diet of meat, fish, and reindeer milk (I have to imagine that’s coming to Whole Foods soon), also gather wild plant foods, particularly berries and mushrooms (Finland’s forests produce 500 million kg of berries and over 2 billion kg of mushrooms each year!), sometimes even feeding their reindeer hallucinogenic mushrooms to produce psychoactive urine. The Maasai are known for their meat, milk, and blood diets, but they often traded for plant foods like bananas, yams, and taro, too, and they cooked their meat with anti-parasitic spices, drank bitter (read: tannin- and polyphenol-rich) herb tea on a regular basis, and used dozens of plants as medicines (PDF). Even Neanderthals used plants as food and medicine, we’re learning.
Even if we discover evidence of carnivory in human prehistory or in some extant group, the emerging science of genetic ancestral differences suggests that the habitual diets of our recent ancestors shapes the optimal diet for us today. If your close ancestors weren’t carnivores, you might not have the adaptations necessary to thrive on an all-meat diet.
Still, what about Vilhjamjur Stefansson, an Arctic explorer who came away very impressed with the native Inuit diet and underwent a series of studies on the effect of an all-meat diet in man? He and a colleague did great for over a year eating only meat. But Stefansson wasn’t eating ground beef. In his own words, he ate “steaks, chops, brains fried in bacon fat, boiled short-ribs, chicken, fish, liver, and bacon.” Definitely carnivorous. Definitely not just steak or ground beef, as many modern carnivores seem to be eating. All those “weird” cuts gave him critical micronutrients otherwise difficult to get from just steak.
How To Best Optimize a Carnivore Diet
While you won’t find me switching to the carnivore side, if I were to do a carnivorous diet, here’s how I’d try to optimize it (and why).
A recent paper showed that the majority of people following a “paleolithic ketogenic diet” with at least 70% of calories from animal foods and including offal had adequate serum magnesium levels. That’s a great start. But earlier studies show that serum magnesium may not be the definitive marker. A person can have normal serum levels but inadequate tissue levels—and in the tissues is where magnesium does its work. A person can have normal serum levels but still be deficient.
They’re not quite animals, but they contain everything you need to build a bird from scratch. That’s cool·—bite-sized whole animal.
Liver is unabashedly animal flesh. It absolutely qualifies for a carnivorous diet. Loaded with choline, folate, vitamin A, copper, and iron, it’s nature’s most bioavailable multivitamin. There’s no reason not to include it. If you get your hands on some fish livers, you’ll get a ton of vitamin D along for the ride.
There’s frozen liver tabs, where people dice up liver into little chunks and swallow them hole.
There’s liver smoothies, where absolute savages blend raw liver and drink it. I know a guy who fixed severe iron deficiency by drinking raw chicken liver orange juice smoothies, with the vitamin C in OJ meant to enhance iron absorption.
Liver is also great sauteed with fish sauce, citrus, salt, pepper, and sesame oil. Do it quick, don’t overcook.
A few oysters, some mussels, a filet of wild sockeye salmon… You’ll get vitamin D, long-chained omega-3s (which tend to rare even in pastured ruminant flesh), selenium, iodine, copper, iron, manganese. Not every meal has to—or should— be a New York strip.
Implement Intermittent Fasts On a Regular Basis
A constant influx of muscle meat will keep mTOR topped up. That’s great for muscle growth and general robustness. Just do something to stop the protein intake for a day or two to lest you start fueling unwanted growths.
Treat Spices and Other Low/Non-Calorie Plant Foods As Medicinal Supplements That Don’t “Count”
All the nearly-carnivorous cultures we have good data on did similar things, using bitter herbs and barks and the like as supplements to their diets. You’re not getting calories from this stuff. You’re getting non-caloric compounds that provide health benefits.
Get the Best Quality Meat You Can Find and Afford
While I’m sure a diet of snare-caught hare, Alaskan elk, and choice sockeye salmon you wrest from the grasp of picky grizzlies poised over rivers preparing for a long winter would be ideal, it’s not necessary. Yes, grass-fed and -finished/pastured as well as organic are ideal, but do the best you can with what you have.
The carnivore diet isn’t for me. I like plants way too much. But I’m cautiously optimistic that it could work for more people than you’d expect, provided they heed as many of my suggestions as possible.
That’s it for me, folks. What about you? Have any experience eating a carnivorous diet? Interested in trying? Let me know what you know!
Where I’m from, snow showers aren’t unheard of over graduation weekends. To this day, I hold to the traditional “Memorial Day to Labor Day” timeline—and, well, here we are finally (or almost anyway). I love summer, which may explain why I fled to Southern California decades ago and just recently migrated to Miami, where life is just as awesome. But even in these warm locales, I still get excited for the summer months themselves. There’s a more casual, maybe even improvisational rhythm, a deeper focus on relaxation, more intention toward fun.
As we head into Memorial Day weekend, today I thought I’d offer up a look at what’s coming to MDA this summer. Because I aim to make it a good one.
Right out of the gate, we’ll be kicking off the season with a staff-led 21-Day Challenge, beginning Monday, June 11th.(Mark your calendars….) Yup, the Bees will be at the helm, sharing their favorite Primal recipes and fitness routines, taking over Instagram, and highlighting their recommendations for active vacations across the globe.
Of course, we’ll have contests—in traditional MDA style. Along with comment giveaways, we’ll be asking you, our community, to submit some of your best Primal work, for our grand prizes. I won’t let the cat out of the bag, but let’s just say for a couple of these you’ll be eating well for a year—and fighting the kids to enjoy the fun. Having seen what the Bees are ready to give away, I want some of these myself now….
We’ll be doubling up with twice the information and resources each day of the Challenge to guide and motivate your 21-Day commitment, however you choose to structure it. We’ll also be serving up Challenge resources on our Vimify app—and, for the utmost in support and instruction, offering a TOTAL reboot of our 21-Day Online Program, now the 21-Day Primal Reset. I’ll have more on that the first week of June, but I’m excited for what this fully expanded, multimedia program will mean for anyone who wants to do the 21-Day Challenge—or get extra support in the powerful initial phase of a Keto Reset.
But that’s not all…. I’ll be announcing several brand-spanking-new Primal Kitchen® products that go hand-in-hand with summer eating and entertaining. (Can you take a guess?) And look for a new Primal cookbook as well next month…this time with inspiration from a different continent.
Beyond the June festivities, we’ll be talking camping food, women’s health, omegas, tea, and grilling recipes to name just a few topics. I’ll also be introducing you to my new digs in Miami, and I’ll share videos on some of the latest strategies I’ve learned and am living—brand new looks at my “day in the life” of Primal food, fitness and sleep.
So, that’s a quick rundown—with much, much more to come. Do you have ideas you’d like to see on MDA this summer? Shoot me line on the comment board, and thanks for reading, everybody. Let’s make this the best summer yet.
Last week, I updated an older post on women and intermittent fasting. For today’s edition of Dear Mark, I’ll be answering some of the comments and questions from that post. First, should a lean woman with a stressful life try fasting to heal her gut? Maybe, maybe not. Second, does coffee break a fast? Now, where have I heard that one…? Is a 12-hour fast a good starting point for women? What are the IF “pre-reqs”? And finally, what do we make of women who can fast successfully? Does habituation have an effect?
I am a 33 yo woman. I am 5’9 and between 129-133 lbs. My longest fasts have been 4 days and we’re medically indicated (i.e. I was hospitalized and not allowed to eat) due to painful flares in my Crohn’s/ileitis (I have recently switched to all meat as my worst flare left me in the worst pain of my life and was from eating veggies/fiber). I naturally do some amount of intermittent fasting (16 to 20 hours).
I am interested in longer fasting than what I do for its potential to help heal my gut, but a several things stop me. 1. I become voracious by about hour 21. I can’t seem to push through. And I have been keto-adapted since August 2017. 2. Though my BMI is in “normal” and I have good muscles, I am on the lean side. 3. Life is kinda intense this year. Yeah, yeah, I meditate and all that. But life has been very intense.
Does anyone have any thoughts on extended IF for gut healing for a lean, probably too stressed, woman?
Check with your doc first. It’s worth a try.
In one study, patients with irritable bowel syndrome (IBS) were fasted for 10 days after four weeks of regular IBS treatment. Another group continued the regular treatment. The fasting group saw improvements in 7 of 10 markers, including abdominal pain, abdominal distension, diarrhea, anorexia, nausea, anxiety, and general interference with life.
Crohn’s isn’t the same as IBS. Crohn’s is generally more serious and can result in physical damage to the gut. But the symptoms are similar enough that this fasting study piques my curiosity.
Improving gut health and reducing inflammation doesn’t require full-out fasting, though.
In obese women, severe calorie restriction (800 calories per day) reduced overall inflammation and improved gut barrier function. They also had a lot of weight to lose, and they lost an average of 15 pounds over 4 weeks. That’s quite good for a short study. It’s hard to know whether it’s the calorie restriction or the weight loss improving the gut health.
Side note: a really cool part of this study is that 14 days after the very low calorie diet, when they were back to their regular diets, the women had gained about half a pound back, but it was lean mass. They actually lost more body fat and had a smaller waist circumference than they did after the 14 day low calorie diet.
My point is that calorie restriction was good enough.
Fasting may very well work for you, but it might not be necessary. It might even be too much of a good thing, given your stress levels. Try it—that IBS study is pretty convincing—and be aware.
Question: I’ve heard both, that black coffee breaks your fast and that black coffee doesn’t break your fast. Opinions? Evidence to either?
Check out my recent post on the subject. It should answer your question.
Micki wrote again:
I’ve reached the point of not trying to force any specific IF protocol other than a regular 12 hour fast every day, which is usually 8pm-8am.. If I go longer, I go longer but I have ceased shooting for any other IF time period. This is what suits me but may not suit anyone else that tries IF. We’re all different, eh?
For what it’s worth, my experience talking with dozens of women is that 12 hours is a sweet spot. Anyone (especially women) curious about fasting should start there, see what happens.
If you haven’t satisfied the usual IF “pre-reqs,” like being fat-adapted, getting good and sufficient sleep, minimizing or mitigating stress, and exercising well (not too much and not too little), you should not fast.
Fat-Adapted: You should have your fat-burning machinery up and running, as fasting places great demands on your ability to burn your own body fat for energy.
Exercise: Too much exercise and you’ll make the fast more stressful than is helpful and hamper recovery. Too little exercise and, well, I don’t have any objective reasons. I just know that exercise and fasting go perfectly together. There’s nothing more delicious and satisfying than a meal after a fasted training session.
I’m a woman, have been skipping dinners for over 5 years, going 12-16 hours with no food daily. I still consume around 2000 cal a day and weigh about 130 lb. My cycles seem to get less regular the more I deviate from this routine and gain weight.
Also if fasting was hurting fertility how do we explain India and other 3rd world countries?
The key here may be your consistency. This conditions your body to expect food (and get hungry at the right time, not before), and it improves the metabolic response to eating.
In one study, the authors actually tested the effect of breaking your eating habits by separating overweight women into habitual breakfast skippers and habitual breakfast eaters and then having them either skip breakfast or eat breakfast.
Habitual breakfast eaters who skipped breakfast experienced way more hunger at lunch, had worse blood lipids, and higher insulin levels. They had worse blood lipids and their insulin skyrocketed. Habitual breakfast skippers who skipped breakfast experienced none of these deleterious effects.
Meanwhile, habitual breakfast eaters who ate breakfast were more satiated at lunch. They had better blood lipids and normal insulin levels. Habitual breakfast skippers who ate breakfast were still hungry at lunch. Eating breakfast didn’t inhibit their regular lunch-time appetites.
Other research has found that maintaining a regular eating schedule improves insulin sensitivity, increases energy expenditure, and improves fasting lipids. Overall, sticking to an (rough, not draconian) eating schedule results in the best metabolic effects, which appears to be what you’re doing.
That’s it for today, folks. Thanks for reading, asking, and writing. Take care!
People who live in small towns and rural areas are happiest, at least in Canada.
New Primal Blueprint Podcasts
Episode 245: Wayne Levine: Host Elle Russ chats with Wayne Levine, who coaches men and helps them become the best fathers, leaders, husbands, and authentic human beings they can be.
Each week, select Mark’s Daily Apple blog posts are prepared as Primal Blueprint Podcasts. Need to catch up on reading, but don’t have the time? Prefer to listen to articles while on the go? Check out the new blog post podcasts below, and subscribe to the Primal Blueprint Podcast here so you never miss an episode.
Primal Kitchen® Sesame Ginger Vinaigrette makes this meal a snap to cook. The dressing provides all the flavor, transforming roasted broccoli and shrimp into an incredible meal with sweet, sour and mildly spicy flavors.
Broccoli really soaks up the dressing well. You’ll probably find yourself cooking broccoli this way again and again, even without the shrimp.
This one-sheet pan meal is easy to cook, and easy to clean up after. It’s a keeper, for sure.
It’s Friday, everyone! And that means another Primal Blueprint Real Life Story from a Mark’s Daily Apple reader. If you have your own success story and would like to share it with me and the Mark’s Daily Apple community please contact me here. I’ll continue to publish these each Friday as long as they keep coming in. Thank you for reading!
My wife and I went Paleo 1/1/2016, initially guided by The Whole 30.
My wife lost weight, and we both passed through carb flu hell. We became virtually illness-free and enjoyed extra daily hours of energy…but I gained weight.
I was committed to grain- and sugar-free living, but confused about my extra pounds. A colleague suggested The Primal Blueprint, which I confess I stayed up all night to read.
The Blueprint’s much more flexible approach to Paleo, or more properly “Primal” eating, snapped things into focus. I learned quickly that I was simply eating too much, and that potatoes (including most sweet varieties) didn’t make sense.
I also learned to dump my grimly desperate gym-rat’s approach to cardio and lifting. Coming up on age 60 in 2018, I now spend 75% of my workout time outside in the sun. Hiking dominates. I added a 20 lb. vest last year to boost intensity.
I now spend more time on my feet than seated, including a stand-up desk at work. I have to be reminded to sit down to eat.
My wife also appreciates the latitude to eat-when-hungry, and the mature, hype-free approach to wine, dairy, chocolate and other “gray area” foods.
We have both lost 30 lbs. I have been sick exactly ONCE since going Primal (first time in 26 months) and have not seen a physician at all. Kathy, a teacher exposed to constant sneezing and coughing students, is ill far less often than her pre-Primal days.
At one point, my weight loss stalled. I went back the Blueprint and realized we were eating a lot of organic chicken. “Organic” doesn’t guarantee correct omega fatty acid ratios, so we reduced our chicken consumption 50%—replacing it with grass-fed beef. Within a few weeks, not only did I lose more pounds but suddenly dropped 3 inches in my waist. It was almost weird.
Even better, we can now look forward to healthy retirement years. My personal success with Primal living got me started researching its long-term health benefits. I now believe we have a real chance to enjoy a disease-free “live long, drop dead” old age.
Timely updates from MDA are a big help, of course. Mark’s patience and commitment to understanding, and examining—not just rebutting—every new fad and study, is a great example to us all. I never hesitate to refer people to MDA, and visit daily.
While I have read many other books and articles about Paleo and Primal living, I am thrilled to say everything just reinforces the foundation I got from The Primal Blueprint.
I am also committed to getting the word out, and have started my own blog, which will be called Paleo55plus.com, devoted to healthy aging through ancestral life choices.
In the face of unprincipled corporate interests and their stranglehold on “popular” information, all we can do is keep sharing our stories and results.
If we have to convert the grainiacs one a time, it’s still worth it.
Insulin does a lot of important things for us. It pulls glucose from the blood and fritters it away into our cells to be burned for energy or stored as glycogen. It prevents hyperglycemic toxicity to neurons, pancreatic cells, the arterial walls and the generation of excessive levels of reactive oxygen species. It even promotes muscle protein synthesis and helps augment muscular hypertrophy, especially following resistance training. Clearly, we need insulin. Without it, we’d die, as type 1 diabetics readily do without an exogenous source.
But this process goes off the rails when our cells become resistant to the effect of insulin over time. We secrete too much. Our levels remain elevated. It becomes harder to burn body fat. In fact, we end up in even more efficient fat storage mode.
I’ve shared about nutritional means to enhance insulin sensitivity in the past. What about other non-dietary strategies?
Since insulin resistance is often the body’s response to energy excess (too much energy in), losing weight (increasing energy out) improves insulin sensitivity. Losing abdominal fat is particularly effective for increasing insulin sensitivity.
Lifting heavy things, particularly with great intensity, improves insulin sensitivity by an interesting mechanism: non-insulin dependent glucose uptake happens immediately after the workout, which allows your muscles to replenish glycogen without insulin. According to some researchers, “the effect of exercise is similar to the action of insulin on glucose uptake.” I’d say not having to secrete any insulin makes you effectively insulin-sensitive.
Practice Sprint Intervals
An overloaded, energy-replete cell is an insulin resistant cell. An empty, “starving” cell is an insulin sensitive cell. Any exercise that burns glycogen and leaves your muscles empty and gaping for more will necessarily increase insulin sensitivity.
Do Full Body, High Volume, High Intensity Training
Glycogen depletion occurs locally: high rep leg presses will deplete leg muscle glycogen, but they won’t touch glycogen in your arms, chest, and back. To fully deplete all the glycogen, you need to do full-body movements.
CrossFit WODs and other similar metcon workouts that have you doing pullups, squats, sprints, pushups, box jumps, and other compound movements—at high volume, in the same workout, and with minimal rest—will drain your glycogen stores and reduce the amount of insulin you need to replenish them.
Trigger Your Relaxation Response
Maybe it’s the quieting of the sympathetic nervous system, the “flight or flight” stress pathway. Maybe brief glimpses of bodhi reduce the amount of insulin required to dispose of glucose. Whatever’s going on, meditation (and likely other relaxation response inducing activities) improves insulin sensitivity.
Trigger Some Oxytocin
So, researchers might have used intranasal oxytocin for their purposes. But oxytocin is what we secrete in response to positive social interactions like sex, good conversation, dinner parties, breastfeeding, cuddling, and petting animals.
One study found that altitude hiking at 4500 meters improved glucose tolerance and insulin sensitivity. This isn’t feasible for everyone (4500 meters is really quite high, and not everyone lives near a suitable mountain). And, in truth, some people just aren’t ready to climb a mountain and hike around (in the study, some participants with low DHEA-S levels didn’t get the benefits), but it’s one way to improve it. Find the closest challenge you can in your region of the country.
Train In a Fasted State
While training of any kind promotes better insulin sensitivity, training in the fasted state enhances this effect. One study found that relatively high-intensity “cardio” performed while fasted increased subjects’ insulin sensitivity beyond the group who did the same training after a carb meal, even in the context of a normally obesogenic high-fat, high-carb diet.
In other words, stay active for life. In a recent paper, both sprinters (aged 20-90 years) and endurance athletes (20-80 years) had far better insulin sensitivity than sedentary controls. Absorb this point: insulin sensitivity didn’t decrease with age in the two active groups. Even the 90-year-old sprinter retained good insulin sensitivity. The sedentary controls? Not so much. That says it all, I think.
Thanks for stopping by today, everyone. Let me know your thoughts, additions and questions below.
This is an updated version of a Dear Mark column from 2012. You can find the original version archived here. The below has been completely updated for 2018.
The blank slate hypothesis has fallen. Everyone comes into this world imbued with attributes, characteristics, and predilections that are uniquely theirs. We’re all humans, but we’re a diverse bunch, and that makes it interesting. And though it also makes giving cookie cutter health advice impossible, I just take that as an opportunity to stand out from the crowd and provide actionable advice that genuinely helps real people.
A perfect example is biological sex. Anyone who’s lived with the opposite sex, been married, or had kids of different sexes knows that males and females are different—on average.
There’s a ton of overlap, don’t get me wrong.
We all need fat, protein, and carbohydrates. We all have the same requirements for sustenance and wellness. We all breathe oxygen, get stronger and fitter when we work out, use the same neurotransmitters, and produce the same hormones. The biological basics are identical.
It’s the details that differ. And matter.
Fasting As Hormetic Stressor and the Influence of Biological Sex
Men and women both need to enter a “fasted” state in order to burn body fat. This should go without saying, but regularly undergoing periods where you’re not inserting calories into your mouth is an absolute requirement for weight loss and basic health, no matter your sex.
These periods are called “fasted states,” and they begin as soon as you stop processing the energy from your meal. An “intermittent” fast is an extended period of not eating done for the express purpose of weight loss and other health benefits.
By definition, a fast is a hormetic stressor—a stressful input (no food) that in the right dose triggers an adaptive response that makes us stronger and healthier. Fasting triggers Nrf2, the “hormetic pathway” also triggered by other hormetic stressors like exercise, polyphenols, and radiation. Nrf2 initiates a series of defensive and adaptive mechanisms that help you respond to the stress and buttress your body against future stressors. But with too large a dose, a hormetic stressor can become a plain old stressor—one that overwhelms our defenses and harms us.
Making matters more complicated, the size of a hormetic dose is relative. What’s hormetic for me might be stressful for you. Many different variables affect how much of a hormetic stressor a person can tolerate.
With fasting, perhaps the most important variable to consider is your biological sex.
This really does make intuitive sense.
Biology cares most about your fertility. Can you reproduce? Can you produce healthy offspring that survive to do the same? These things come first.
And from that perspective, a woman’s situation is more precarious than a man’s.
You have a finite number of eggs, or “chances.” Men have an almost infinite supply of sperm.
When you are preparing to get pregnant, your body needs extra nutrients to build up a reserve and “prime the pump.”
When you are pregnant, the growing baby needs a reliable and constant stream of nutrients for almost a year. After a man gets someone pregnant, his biological involvement with the growing baby is done. What or when he eats has no impact on the survival of the growing baby.
After you’ve given birth, the growing newborn needs breastmilk. To make that milk requires additional calories and extra doses of specific nutrients. Modern technology allows us to skip nursing and go straight to the bottle, but your body doesn’t “know” that.
It all points to women being more finely attuned to caloric deficits. For example, women’s levels of ghrelin, the hunger hormone, are quicker to rise after meals.
This isn’t just relevant for parents or parents-to-be. Even if you’re not interesting in getting pregnant and having kids, or you have children and aren’t planning on any more, the ability to do so is strongly connected to your health. Reproductive health is health. As far as your body’s concerned, having kids is the primary goal and you need to be ready to do it as long as you’re able.
Where does fasting come in?
Fasting is simulated starvation. Amidst the most critical junctures of the reproductive process, even a single skipped meal can register as trouble. The problem with intermittent fasting is that it’s not just a one time thing. It’s a regular occurrence. Depending on the schedule you follow, you might fast every day, every other day, or once or twice a week. To the mostly unconscious body whose primary concern is your fertility, that can be alarming.
What does this mean for women interested in intermittent fasting Unfortunately, there aren’t many studies examining this question in women. There are a few, and I’ll get to those. First, let’s move to animal research.
What Animal Studies Tell Us
In male rats:
No matter the duration or degree of nutritional stress, a male rat’s brain chemistry responds with similar changes. Nocturnal activity and cognition stay fairly stable, regardless of the intensity of the fast. If you push the fast long enough, males will get a little wonky and frantic, but overall they maintain pretty well. It’s like they’re equipped with the ability to handle nutritional stressors.
In female rats:
Any degree of nutritional stress (fasting or mere caloric restriction) causes increased wakefulness (during the day, when they normally sleep), better cognition (for finding food), hyper alertness, and more energy. In short, female rats become better at finding and acquiring food when they fast, as if their bodies aren’t as well-equipped to deal with the stress of going without food. They also become less fertile, while the males actually become hornier and more fertile (probably to account for the females’ plummeting fertility). Ovary size drops (bad for fertility), adrenal gland size increases (which in rats indicates exposure to chronic stress), and menstrual cycles begin to dysregulate in proportion to the degree of caloric restriction.
One recent study found that placing young rats of both sexes on an intermittent fasting schedule had negative effects on fertility. While the male rats had lower testosterone, the female rats stopped ovulating, had trouble sleeping, and experienced ovary shrinkage.
What Human Studies Tell Us
One study found that while IF improved insulin sensitivity in male subjects, female subjects saw no such improvement. In fact, the glucose tolerance of fasting women actually worsened. Another study examined the effect of alternate day fasting on blood lipids. Women’s HDL improved and their triglycerides remained stable; men’s HDL remained stable and their triglycerides decreased.
Later, both obese men and women dropped body fat, body weight, blood pressure, total cholesterol, LDL cholesterol, and triglyercides on a fasting regimen. These people were obese, however, and perimenopausal women were excluded from the study, so the results may not apply to leaner people or women in the perimenopausal window.
One study compared continual calorie restriction (lower calories a little bit every day) to intermittent calorie restriction (lower calories a lot every once in awhile, similar to fasting) in overweight and obese women. Both groups lost a similar amount of weight, but the intermittent restriction group lost significantly more lean body mass. As I’ve always said, the kind of weight loss we want isn’t “weight loss.” It’s fat loss and lean mass retention (or gain).
In the only heretofore extant human study on fasting and chemotherapy, seven females (including a 44-year old woman who was likely premenopausal, given when menopause usually onsets, though it wasn’t explicitly stated) and three males found that IF improved their tolerance to and recovery from chemotherapy.
Takeaway: male and female (mostly middle-aged, though that’s the population that generally gets cancer and undergoes chemotherapy) chemotherapy patients appear to benefit equally from IF.
What About the Effects of Training While Fasted?
One study looked at healthy men and women doing moderate intensity morning cycling either fasted (overnight) or fed (ate breakfast). Although both men and women displayed greater increases in VO2 max and resting muscle glycogen concentration in response to fasted cycling training, only men showed greater skeletal muscle adaptations when fasted. Women had better muscle adaptations when fed.
Another study placed both fasting and fed overweight women on an interval training protocol for six weeks. Both groups improved body composition and oxidative capacity to an equal degree. Being fasted or fed had no effect.
It’s sad to say, but that’s about it for fasted training studies in women. The vast majority deal with men.
How About the Psychological Effects Of Fasting?
In women, a two day fast shifted nervous system activity toward sympathetic dominance. Even though their cognitive function was unaffected, they were stressed out. In men, a two day fast shifted nervous system in the other direction, toward parasympathetic dominance. They were well-rested and relaxed. Their blood pressure dropped. Their cognitive performance improved.
How About Autophagy?
One of the main benefits of intermittent fasting is an increase in autophagy, the process by which our body clears out cellular debris and repairs damaged cellular structures like mitochondria. A decrease in autophagy is usually linked to increased aging; an increase in autophagy tends to stave off the ravages of aging.Fasting-induced autophagy is usually a good thing.
One of the most commonly-cited papers in the intermittent fasting literature is this one, which shows how short term fasting induces “profound” neuronal autophagy. Only that might not be true for both sexes; another study shows how while “male neurons” respond to starvation as we’d expect—by undergoing autophagy—”female neurons” respond by resisting autophagy.
Less autophagy isn’t necessarily a bad thing. Certain diseases take advantage of the autophagy process, turning it against us by clearing out and killing healthy cells, and women tend to be less vulnerable to these diseases. But if you’re a woman aiming for autophagy, fasting may not be as reliable an induction method.
My Conclusion…For Now
As it stands right now, I’d be inclined to agree that pre-menopausal (and perhaps peri-menopausal) women are more likely to have poor—or at least different—experiences with intermittent fasting (at least as a weight loss tool). That said, it appears to be a potentially gender-neutral therapeutic tool for chemotherapy, cancer, and age-related neurodegeneration patients.
So, Who Should and Who Shouldn’t Consider Fasting?
Have my recommendations changed?
If you haven’t satisfied the usual IF “pre-reqs,” like being fat-adapted, getting good and sufficient sleep, minimizing or mitigating stress, and exercising well (not too much and not too little), you should not fast.
These pre-reqs are absolutely crucial and non-negotiable, in my opinion—especially the fat-adaptation. In fact, I suspect that if an IF study was performed on sugar-burning women versus fat-adapted women, you’d see that the fat-burning beasts would perform better and suffer fewer (if any) maladaptations.
I would also caution against the already lean, already calorie-restricted woman jumping headfirst into IF. I mean, fasting is ultimately sending a message of scarcity to your body. That’s a powerful message that can get a powerful response from our bodies. If you’re already lean (which, depending on the degree of leanness, arguably sends a message of scarcity) and restricting calories (which definitely sends a message of scarcity), the response to fasting can be a little too powerful.
I’d also say that daily fasts, a la 16/8 or even 14/10, run the risk of becoming chronic stressors and should be approached with caution by women. Same goes for ultra-long fasts, like a 36 (or even 24) hour marathon.
Most of all, however, I’d simply suggest that women interested in fasting be cautious, be self-aware, and only do so if it comes naturally. It shouldn’t be a struggle (for anyone, really). It shouldn’t stop your cycle or make it harder for you to get pregnant. It should improve your life, not make it worse. If you find that fasting has those negative effects, stop doing it. It should happen WHEN (When Hunger Ensues Naturally), if it happens at all.
Some Warning Signs To Watch For
Weight Gain (especially in the midsection)
Muscle Loss or Reduced Performance In the Gym—It’s perfectly reasonable to suffer in the gym on fasting days, but watch out for persistent strength losses. If your fitness and strength levels are consistently trending downward, fasting may not work for you.
Loss Of Your Period—Skip meals, not menstrual cycles.
Excessive Hunger—Feeling peckish is good for everyone and makes food taste better; constant satiation is a trap of modernity. But you shouldn’t be ravenous. Thoughts of food shouldn’t consume you.
The good news is that most of the ill effects of fasting are blatant and conspicuous. They don’t hide. They don’t lurk in the background. They’re really hard to ignore—so don’t!
Some Thoughts For Women Who Want to Fast
Instead of aiming for the longest fast you can tolerate, aim for the shortest fast that gives results. Don’t try to power through a 24 hour fast, braving headaches and foggy thinking and overpowering hunger. Do try eating dinner earlier so you get a good 12 hours of “fasting” simply by going to bed and eating breakfast at a normal time.
Don’t fast unless you have a good reason. Good reasons include:
Having significant amounts of fat to lose.
Your oncologist giving you the go-ahead to try using it to improve the effects of chemotherapy.
Your neurologist giving you the go-ahead to try using it to improve brain function in the face of cognitive decline or dementia.
Bad reasons include:
Keeping the pregnancy weight at bay.
Going from 15% body fat to 12%.
To boost your 5x weekly CrossFit sessions.
Men and women have inherent metabolic and hormonal differences, and it’s evident that these differences in part determine how we respond to a stressor like intermittent fasting. I’ve never prescribed intermittent fasting as a requisite piece of the Primal lifestyle, but rather as an elective addition, a personal choice—only as a potentially therapeutic strategy that each individual must test for him or herself.
I generally fast when it makes sense – if I’m traveling and good food isn’t available, if I’m just not hungry, stuff like that. I periodically do 16/8 or 14/10 (i.e. eating in an 8 or 10 hour window) and find it works great for me because I am fully fat-adapted. But even I don’t hold rigidly to that. It’s not for everyone. And that hasn’t changed.
That’s it for me, today. What about you? If you’re a woman who has tried fasting, or know someone who fits the description, let us all know about your experiences. I’m intensely curious to hear from as many of you as I can. Thanks for reading.
By the way…because this is an updated version of a previous article (as I noted at the beginning), previous comments will still display. Keep in mind they may refer to the context of that previous article version.
It’s certainly getting easier to find healthier snacks at the store, but the convenience of healthier, pre-packaged snack food often comes at steep price. For most of us, homemade snacks are still the most practical, budget-friendly option.
For convenience, stick with whole food snacks that require little or no cooking. Fresh fruit, cut up veggies, olives, pickles, nuts and nut butter, sardines, soft- or hard-boiled eggs, and high quality cheese are always delicious choices.
And when you have a little more time to spend in the kitchen, try one of these favorite Primal snacks.
Frozen Yogurt Bark
This tart and refreshing icy treat is great for hot days. Try different versions using frozen blueberries, mango, shredded coconut, nuts, or maple syrup instead of honey.