Mark Sisson's Blog, page 215

The Fat Burning Brain: What Are the Cognitive Effects of Ketosis?

Although mainstream sources still mistake “the brain needs glucose” for “the brain can only run on glucose,” regular MDA readers know the truth: given sufficient adaptation, the brain can derive up to 75% of its fuel from ketone bodies, which the liver constructs using fatty acids. If we could only use glucose, we wouldn’t make it longer than a few days without food. If our brains couldn’t utilize fat-derived ketones, we’d drop dead as soon as our liver had exhausted its capacity to churn out glucose. We’d waste away, our lean tissue dissolving into amino acids for hepatic conversion into glucose to feed our rapacious brains. You’d end up a skeletal wraith with little else but your brain and a hypertrophied liver remaining until, eventually, the latter cannibalized itself in a last ditch search for glucose precursors for the tyrant upstairs. It would get ugly.

That’s adaptation. But is there an actual cognitive advantage to running on ketones?

Maybe. It depends. It certainly helps people with neurodegeneration.

People whose brains suffer from impaired glucose utilization see cognitive benefits from ketones. In Alzheimer’s disease, aging-related cognitive decline, epilepsy, and Parkinson’s disease, brain glucose uptake is depressed—even before any actual cognitive decline appears. Despite high glucose availability, the aging, epileptic, Alzheimer’s, or Parkinson’s brain can’t utilize enough of it to handle cognition. Enter ketones. Ketones act as an alternative energy source for the glucose-starved brains. It’s no coincidence that ketogenic diets can improve symptoms (and in some cases abolish them) and cognitive function in all four conditions.

Okay, but those are in unhealthy people with existing (or looming) neurological deficits and disorders. What about healthy people? What about you?

Anecdotes certainly suggest that otherwise healthy people can experience cognitive benefits from brain utilization of ketones. The entire butter/coconut oil coffee movement is predicated on ketone production—from morning fat bombs (especially medium chain triglycerides in coconut oil, which convert directly into ketones regardless of carb intake) and very low carb intakes—improving mental clarity, focus, and performance.  In people with “mild cognitive decline” rather than full-blown Alzheimer’s, a ketogenic diet improves memory. It hasn’t been validated in controlled trials of healthy subjects, but the fact that it’s a “movement” and shows efficacy in “unhealthy” brains suggests it’s worth exploring.

There are some interesting studies, to be sure, albeit not in totally healthy people. Such is the way of medical research.

Type 1 diabetics who experience reduced cognitive function because of low blood sugar see those deficits erased by increasing BHB through dietary medium chain triglycerides (the same fats found in coconut oil).
In memory impaired adults, some with Alzheimer’s, BHB improved cognition. Scores improved in (rough) parallel with rising ketones.
A ketone-elevating agent (purified medium chain triglycerides) improved cognition in patients with mild to moderate Alzheimer’s.
A very low-carb diet improved memory in older adults. Again, ketones tracked with improvements.

If there are benefits, what’s going on?

Brain mitochondrial biogenesis

Ketosis upregulates mitochondrial biogenesis in the brain. It literally creates new power plants in the brain that are good at burning fat-derived fuel. This upregulation is actually responsible for the anticonvulsant benefits in patients with epilepsy, and, likely, the benefits seen in other brain disorders with glucose uptake problems. By providing an alternate source of brain power, brains that don’t run so well on glucose can begin burning fat. There’s no indication that ketosis only induces mitochondrial biogenesis in “unhealthy” brains. It simply hasn’t been studied yet, but I don’t see why it wouldn’t also build mitochondria in healthy brains.

There’s reason to believe ketone-induced mitochondrial biogenesis in the brain will improve its function.

For one, extra energy sources are always nice to have. That they might improve the way your brain works makes intuitive sense.

Two, exercise, perhaps our most reliable and potent booster of mitochondrial biogenesis in the brain, is downright nootropic. Exercise increases blood flow to the brain, which provides more oxygen and energy but also reduces free radical damage and enhances memory. It stimulates the creation of new neurons and the production of brain-derived neurotrophic factor (BDNF), a chemical that is instrumental in neuron preservation and formation. Exercise also promotes gene expression that supports plasticity, the brain’s crucial power to alter neural pathways.

If exercise promotes mitochondrial biogenesis and better functioning in the brain, perhaps ketosis does, too.

Brain fog clearance

Elevated ammonia levels and depressed GABA levels contribute to a condition called “brain fog.” We’ve all had it. Everything is muffled. Your synapses fire blanks, your neuronal communication medium is cold molasses. Works suffers, nothing gets done.

According to a very interesting post from Dr. Bill Lagakos of the always interesting Calories Proper blog, ketosis has the potential to alleviate brain fog. There’s a lot of biochemistry thrown around, so geeks are advised to read the post in full, but two big, relevant takeaways are these:

Ketosis increases brain glutamine synthetase, and brain glutamine synthetase mops up extra ammonia.

Ketosis increases GABA signaling. GABA is the “chill-out” neurotransmitter. It opposes glutamate, the excitatory neurotransmitter. We need both for cognitive function (or else we wouldn’t make both), but too much glutamate can lead to neuronal injury and neurodegeneration. GABA is the counterbalance.

Euphoria infusion

Ketone bodies are known to increase feelings of euphoria in some people.

Of course, that isn’t always good for productivity and mental performance. If you experience high “affect intensity”—if euphoria hits you hard—then it might actually decrease your mental performance.

I know that the first cup of coffee after a great night’s sleep foments a heady dose of optimism tinged with focus that always leads to a productive morning. Maybe being a fat-burning beast in mild ketosis from the overnight fast is an additive.

I’m not surprised by any of this. For most of human history, a regular person would be regularly exposed to ketosis. Mostly light and transient, sometimes more protracted. But they were never far from a mildly ketogenic state for many reasons.

Long breastfeeding: Breastfed infants are in a mild state of ketosis (this is different from being on a very low carb diet, which babies are not!).

More meals, less snacking: Light ketosis in between meals, assuming fat-adaptation.

More structured meal times, less eating late at night: More nighttime ketosis.

Occasional fasting (the tribe going hungry, the hunter coming up short, the free range pre-1990s child being out all day and forgetting to eat): Full-blown ketosis.

This was “enough” to keep things in check and, likely, hold off neurodegeneration. Most of us are only learning about ketosis after a half or quarter lifetime of standard Western eating patterns. We’ve been snacking, overweight, unable-to-skip-a-meal sugar-burners, and we probably need a stronger intervention. That’s where ketones, ketogenic diets, and fasting come in.

You don’t even have to start counting the carbs in your leafy greens. There are ways to cycle between ketosis and higher-carb days, outlined in this post. There are also other ways to set up a meeting between ketones and your brain without changing your overall diet.

Here are a few.

Fasting: A fast quickly induces ketosis. You’re not eating anything, so your only option is to consume your own body fat. And to offset the lack of incoming glucose, your brain will run partially on ketones. It helps to be a strong fat-burner already, as you’ll start dipping into your body fat stores right away and everything will go more smoothly. Anyone who’s fasted without being fat-adapted can attest—it’s not easy.

Don’t eat too late: Even just a “fast” from dinner to breakfast is enough time to induce a little ketogenesis. Ketosis is a spectrum, not a binary. By eating earlier and avoiding midnight snacks, you allow your body to start burning fat and converting it into ketones. You’ll know it when you have funky ketone breath in the morning; it’s a sign of a good metabolism (PDF).

Eat medium chain triglycerides: Adding MCTs, found in coconut oil or isolated MCT oils, to a regular diet spurs the creation of ketones. You don’t even have to reduce carbs, although I probably wouldn’t recommend trying a high-carb, high-MCT oil diet. Might get weird (see the next section).

Eat ketone esters: “Eat” may be optimistic. “Do everything in your power to mask the flavor” is more accurate. These things are foul. But man do they quickly induce ketosis. I’ve taken them to experiment. Pretty hard on the digestive tract. They require a ton of taste alteration to get past the nastiness. I swear I get some funky stomach effects from some of them almost instantly, but I do notice I can play two hours of hard Ultimate with no other fuel.

I think they are awesome for a fat-adapted athlete. I doubt their efficiency and wonder about their safety in a sugar burner. In nutritional ketosis, or during fasting, both free fatty acids and ketones are elevated. This is normal. It’s physiological. When you add ketone esters to a regular diet, free fatty acids are low. This is unprecedented. Peter over at Hyperlipid is suspicious. He doesn’t like “faking ketogenic diets.” Tread lightly.

Primal Endurance training: Low-level aerobic activity is awesome for starting ketosis. 180 minus your age = the heart rate you need to stay at or under to maximize fat burning efficiency, lay your aerobic base, and upregulate mitochondrial biogenesis. Do this on an empty stomach and you’ll kickstart ketosis.

I don’t think we all need to be on a ketogenic diet, nor do we need to remain in ketosis for long periods of time. I do think we need to slip into ketosis every once in awhile, because we seem to be built for doing it and derive benefits from it. We know in the short term (and probably longer term) it’s safe. We know it seems to stave off neurodegeneration, as well as improve the brains of people already suffering from it. What we don’t know is if it will provide nootropic benefits to healthy individuals.

I suspect the occasional foray into ketosis will help you think, perform, and produce. I’ve felt it myself.

How about you? Has the fat-burning brain been a boon to your business?

Thanks for reading, all. Take care.

Dear Mark: Swimming Tips; High Weight, Low Reps vs High Reps, Low Weight

For today’s edition of Dear Mark, I’m answering two questions. First up are some swimming tips for a novice swimmer who read last week’s post and wants to incorporate swimming into the schedule. What strokes to learn? What workouts to try? I also discuss the downsides of chlorinated pools. Next, a new study claims that whether you lift heavy weight for low reps or lift light for high reps has no effect on strength or size, so long as you go to failure. Is this true?

Let’s go:

Hey Mark, really liked the swimming post. Got any tips for someone without much experience in the water? I’ve also heard that chlorinated pool water is a concern…that true?

Thanks for all you do!

Learn to tread water. Treading water should be easy. It’s like standing, on land; it’s the default mode. Once you can tread for 5 minutes without freaking out or struggling, progress to actual swimming.

Start with, and maybe even stick to, basic freestyle. It’s a great stroke with strong fitness potential. You don’t ever have to progress past this if you don’t want. Take lessons, read books, or watch videos to learn; technique is really, really important here.

Butterfly is the “hardest” stroke. If you can get the technique down (it’s tricky), you really develop explosive power.

Breaststroke is the “easiest.” In fact, I make it a point to do some breaststrokes in the pool whenever I do my post workout cool-downs to stretch my muscles out.

Learn to dolphin kick. It’s an extremely powerful and empowering way to move through the water that uses the entire body, not just “the legs.”

I’ve had fun with a quick sprint workout lately. Sprint one length freestyle. Spring one length dolphin kicking on your back, keeping your head out of the water and your hands on your chest. Sprint two lengths freestyle. Done. Do 3-6 more cycles, depending on the length of a “length.” Get ready for sore hamstrings (those dolphin kicks are no joke).

Loosen up with an easy 5-10 minutes of breaststroke. This’ll really stretch out your tissues and prepare you for sleep if you can hack it toward the end of the day. Of course, if you want to go hard, breaststroke can leave your lats and triceps incredible sore.

More advanced swimmers looking to train their swimming can use a program like Swim Smooth, which I hear good things about.

Beware the “post-swim appetite.” As mentioned earlier, being in cool water forces you to burn more calories (via brown fat activation) to maintain your body temperature. This makes you hungrier than normal. As a result, swimmers tend to eat more food than other athletes, and several studies have found that swimming has little to no effect on fat loss compared to equivalent amounts of other types of training. If you can resist the massive spike in appetite many people experience after swimming, however, you’ll likely burn a little extra fat.

If swimming is your primary form of training, make sure you’re also lifting heavy things and getting plenty of magnesium. Lifting provides the impact you (and your bones) are missing, and magnesium intake is especially important for a swimmer’s bone mineral density. Supplement, eat spinach/almonds/blackstrap molasses.

What about the swimming medium—should you stick to “ancestral bodies of water” like salt water pools, lakes and rivers, and the ocean?

If you can, yes. Chlorine tends to react with various bodily fluids to form disinfection byproducts, or DBPs. Some DBPs have unpleasant health effects or are associated with unpleasant health conditions. When chlorinated pool water meets dimethylamine (found in urine and sweat), nitrosamine carcinogens form, and appear in pools at concentrations up to 500-fold higher than drinking water. These nitrosamines may be absorbed through skin. Chloramine, another DBP has been linked to asthma in pool workers and elite swimmers. All told, you can find over 100 chemical byproducts in swimming pools, many of them toxic.

But swimming in chlorinated pools is better than not swimming at all, and the people who seem to suffer the most from pool-related maladies are those who spend inordinate time in and around pools, especially enclosed ones. Elite swimmers with their 4 hour practices and lifeguards who breathe the fumes for 8 hours a day are probably most at risk. Folks swimming for pleasure and a short workout or two a few times a week, not so much.

Most of all, have fun with it. Make sure every visit to the pool is an enjoyable one. You’re a beginner and you don’t want to learn negative associations.

Mark,

Curious about your thoughts on this research: http://qz.com/730915/lighter-weights-...

It’s a very cool study (PDF).

Here’s what happened:

Young men with at least two years of lifting experience were split into two training groups for 12 weeks. One group lifted lighter weights (30-50% of their one rep max) for 20-30 reps. The other group lifted heavier weights (75-90% of one rep max) for 8-12 reps. Both groups trained to failure, lifting until they couldn’t.

On Mondays and Thursdays, they did inclined leg press/seated row supersets, barbell bench press/hamstring curl supersets, and front planks. On Tuesdays and Fridays were machine overhead press/bicep curl supersets, tricep extension/wide-grip lat pulldown supersets, and machine knee extensions. So while they weren’t hoisting barbells and doing Olympic lifts, these were primarily compound movements.

Each session, subjects did three sets of each exercise. Researchers adjusted the weight between sets to maintain the prescribed rep ranges.

After 12 weeks of this regimen, they ran some tests on the subjects.

Both groups experienced similar gains in strength (one rep max) and hypertrophy. The only difference lay in the bench press one rep max. The subjects who lifted heavier weights for fewer reps saw larger strength increases in that lift.

Other studies  have found similar results. Neither load nor volume matter much when you compare moderate to high reps, as long as the trainees push themselves to failure. Effort seems to be the key factor.

Yet that’s not the final word. When you compare 8-12 reps at 70% of 1RM to 3-5 reps at 90% of 1RM with back squats and barbell bench presses, things change. The higher-intensity, lower-rep regimen resulted in bigger arms and a higher max bench. Max squat and leg development, which didn’t differ between rep schemes, may benefit equally from higher volume and higher intensity.

To be absolutely “safe,” you can try all three. Oscillating between low reps, heavy weight (3-5 reps, 90% 1RM); medium reps, medium weight (8-12 reps, 70% 1RM); and high reps, low weight (30-50% 1RM) may be an effective way to reap the benefits of all three regimens.

This is an interesting topic. I may revisit it in a future post.

Thanks for the questions, everyone. And thanks for reading! Be sure to chime in down below if you have anything to add—or ask!

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Weekend Link Love – Edition 409

Research of the Week

New evidence from China is changing the story of human evolution.

Vets with PTSD may have traumatic damage to their pituitary glands.

Some criticisms of the latest epidemiology from Harvard indicting saturated fat.

A new meta-analysis concludes that taking probiotics can improve weight loss.

Nail-biters and thumb-suckers may have better immune systems and fewer allergies.

Is autism a disorder of high intelligence?

Plants can, like, totally sense electric fields.

New Primal Blueprint Podcasts

Episode 126: Dr. Glenn Livingston: Host Elle Russ hangs out with Dr. Glenn Livingston, a veteran psychologist and food consulting firm CEO. When major media outlets need an expert to talk about food addiction, bingeing, and overeating, Dr. Livingston (I presume) is often their guy.

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.

How Much Meat is Too Much?
Why a Sense of Adventure is Important (and 22 Ways to Cultivate It)
12 Reasons Why Swimming is an Essential Primal Skill

Interesting Blog Posts

Why pregnant ladies walk like that.

Good sleep tips (that no one [but us] follows).

Sorry, sashimi fans: you’re probably a cultural appropriator and a terrible person.

Lessons we learn from training.

Media, Schmedia

This gives me some ideas for the office.

An Alaskan adventure.

Good news: major diseases are on the decline.

Everything Else

Broccoli pickers may soon be replaced by robots.

Everyone knows exercise is good for the brain. But which exercises work best?

Stress-induced cortisol spikes show up in mother’s milk, and this could be a necessary evil.

A free new database of cultural, linguistic, environmental, and geographical information for over 1400 human societies.

Some no-name is proposing sick days for poor mental health.

If you’re gonna eat insulin-spiking foods, they might as well be nutrient-dense.

Pokemon Go is making people go outside more than ever before.

Kale is the new frontier of competitive eating. “But 25 bowls of kale was not enough to fill him up. ‘I’m still hungry, I’m going to go eat some real food,’ he said, before wandering off with his shiny Kale Cup.”

Wild bulls are returning to Croatia.

Recipe Corner

Paleo bacon jalapeño hummus. Your Lebanese pal might not recognize it, but it’s damn good.
Abel James shows you how to throw together a little backyard feast.

Time Capsule

One year ago (Jul 17 – Jul 23)

The Primal Laws: 8 Honorable Mentions – Other guidelines to consider.
From “The Games” to “The Cert”: The Story Behind the Grundler Brothers  – Two brothers’ journey.

Pic of the Week

Be careful with genetic testing.

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Chicken Korma

Chicken korma is an Indian dish that uses full-fat yogurt to both tenderize the chicken and make a creamy sauce as it cooks. This is a streamlined recipe, turning chicken korma into a straightforward but still very flavorful weeknight meal.

Yes, the ingredient list is long. But more than half of the ingredients are herbs and spices, most of which you probably already have on hand (although, if you’ve had them on hand for more than a year, it’s time to re-stock the spice cabinet).

Herbs and spices are an important part of the Primal food pyramid and an important part of chicken korma. The spices give korma layers of flavor, but don’t make it “spicy hot.” The spices also contribute outstanding levels of antioxidants. So with every bite, you’re not only getting a delicious meal, you’re also building a strong defense against disease.

Servings: 4

Time in the Kitchen: 50 minutes

Ingredients:

2 pounds boneless, skinless, chicken thighs, cut into 2-inch/5cm pieces and seasoned with salt (900 g)
1 2-inch/5 cm piece ginger, peeled and chopped
3 garlic cloves
1/3 cup (1.75 oz) raw, unsalted cashews (ideally, soaked in water 4 hours) (50 g)
1 cup (8 ounces) plain, full-fat yogurt (225 g)
4 cardamom pods, smashed
2 teaspoons coriander (10 ml)
1/2 teaspoon turmeric (2.5 ml)
1/2 teaspoon black pepper (2.5 ml)
1 teaspoon kosher salt (5 ml)
1 cinnamon stick
2 whole cloves
2 bay leaves
2 tablespoons butter (30 g)
1 teaspoon garam masala (5 ml)
1 onion, thinly sliced
1/3 cup chopped cilantro (80 ml)

Instructions:

In a blender or food processor, combine the ginger, garlic, cashews and 1/3 cup/80 ml water. Process until very smooth. If you need to add a little more water to get a smooth consistency, do so.

In a large bowl, combine the cashew puree with the yogurt, cardamom pods, coriander, turmeric, black pepper, salt, cinnamon stick, cloves and bay leaves. Add the chicken and mix well to coat.

In a Dutch oven or wide pot, melt the butter. Add the garam masala and the onion, and cook over medium heat until soft and brown, 7 minutes. Add the chicken and yogurt mixture.

Cover the pot and bring to a simmer. Once the mixture is simmering, remove the lid and continue to simmer gently, stirring occasionally, until chicken is cooked through and tender, about 30 minutes.

Garnish with cilantro and serve.

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How Primal Has Helped Me in My Battle Against Multiple Sclerosis

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!

As the old quote goes, “A picture is worth a thousand words.”

I knew I would be embarking on great changes in my life when I decided to document my photos of how I looked before Paleo. I was not shamed by my body nor embarrassed, however, I wanted to remember how I felt. My body felt expanded. I felt heavy and had pains and aches. I am still a work in progress but I am happy to show you the difference through pictures that my body has gone through due to changing to a Paleo lifestyle.

I started my Paleo transition in March of 2014 after reading Terry Wahls’ The Wahls Protocol and following Mark’s Daily Apple. I knew that it was time to make a change. You see, back in December of 2006, I was diagnosed with Multiple Sclerosis and at the time had lost complete feeling in my legs, was unable to walk without some sort of assistance, and I was unable to drive. At the time, I was at the young age of 26 being diagnosed with a disease with no cure. I had just graduated with my Bachelor of Science in Business Management and felt I had so much ahead of me. Then in one moment, I felt as if my life and soul was taken from me. I was very thankful that at the time I lived with great friends that were like family and helped care for me during a very difficult time. Happily, I was able to eventually feel my legs again and drive! I found a job that I loved and continued to move forward with my life, however, there would be moments that my disease would flare up and knock me down.

The most popular form of treatment is steroids for flares and various drugs to keep the disease from progressing. I would have to say I nearly took every drug on the market for the disease, and each one made me sick, or would have such bad effects on my quality of life that it became overwhelmingly depressing. However, I would continue to push forward and even met a wonderful man, who is now my husband, and we had a son in 2011. Again I faced some ups and downs with my disease, but I continued to be proactive, ultimately deciding to go off medication and try stem cell therapy. Stem cell therapy was one of the best things ever to calm my disease and allow me to feel “normal.” Sadly, after putting my family in major debt, I ended up having a flare about six months after. It was not long-lasting, but the flare was bad enough have reality hit home that I needed to do something more.

Enter the world of Paleo—I finally understood the power of food and what it could do to help our bodies and minimize inflammation. I was lucky to be part of a study that allowed me the opportunity to try stem cell therapy once more, in conjunction with being Paleo, and it has been over two years since my last flare!!!!

Of course I feel Paleo is not a one size fits all style of life, hence my blog, The Paleo Mix. It is important that you know that I am a mixer of sorts. I take pieces of Paleo from several sources along with dabs of other ideas. I am a mix of Paleo, AIP Paleo, and other protocols.

I also have chosen to not use any medications for my disease. Instead I use supplements and my doTERRA oils. Now I am by no means against medication, and if needed, I will look at the options of its benefits and whether a particular medication is worth using for me and my family. That being said, and long story short, I take care of my health and well-being by eating and living a Paleo Mix life, along with supplements and my doTERRA essential oils and, of course, making sure to live life and laugh!

Johanna

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Don’t Be So Sure: Why Doubt Is an Essential Tool for Reaching Health Goals

I’m sure we’ve all found ourselves around people who are absolutely hamstrung by their beliefs—whether about business or healthy eating, politics or fitness. Some people are overly sensitive or even overtly defensive when discussing them. Others might be congenial but simply shut down when the conversation turns to a “sacred” topic. But if conviction hampers them this much in social exchange, can you imagine how much it hampers them in the rest of their lives? Many of us tend to perceive certainty as a strength, but often it can cut us off from imagining a scope of better options. Over the years, people have invested so much time, energy and justification in their opinions that the cost to entertaining other possibilities seems too high. And that’s too bad. Because as the old saying goes, the only thing worse than making a mistake is to keep making it. That’s why today I want to talk about the value of doubt.

Productive doubt, I’ve found, applies just as much in health considerations as it does in other areas of life. Conventional health wisdom unfortunately continues to reign, after all, not because it’s incontrovertible truth, but because it’s a convention that society refuses to question. As a result, we have more people than ever who suffer from obesity, diabetes, and other lifestyle diseases. In the end, the more certain (i.e. hard-headed) we are, the more limited we’ll inevitably be. That reality can both compromise our personal health and erode our belief in positive health change.

At first, it might seem strange that I’m even making the case for doubt. After all, here I am more than a decade into promoting a specific blueprint for health, weight loss and vitality. However, those of you who have been around here for a while know I’m anything but a fixed thinker. I have never, nor will I ever, suggest anyone give me or the Primal Blueprint blind faith. Please don’t check your skepticism at the door here. By all means, inspect and scrutinize. Put the plan and all its principles fully under the microscope of your own experience. I’ve always said I’ll follow the Primal Blueprint until someone shows me something better. That day hasn’t come, but one day it might, and I’ll be genuinely grateful for the insight if and when it does.

I grew into the Primal Blueprint philosophy over decades of experience and experimentation as well as study. If my mind hadn’t been open and stayed open, the PB never would’ve gotten out of the gate, let alone evolved over the last several years to become an inclusive, but loose design for flourishing. And I fully trust it will keep developing into new areas, highlighting new principles.

Because here’s the rub.

When we seat ourselves in certainty, we abandon curiosity. We see the effects of this in everything from government to parenting, science to education. Those who are convinced they know what they know despite evidence to the contrary have cut themselves off from learning, from growing, from expanding. Can you imagine what our world would be like today if a hundred years ago we collectively decided that we had already discovered and invented everything worth discovering or inventing? What if we’d settled on it even ten years ago? Thankfully, enough of us throughout history (and our current times) are driven by a pretty insatiable curiosity that leads us to doubt the status quo whenever possible.

Tunnel vision certainly never got Grok anywhere—literally or figuratively. At some point, someone always had to doubt that the same old means for x, y or z wasn’t the best approach. It took a while, but the human species over time continually found better ways to do things, easier methods to gain the same results for less effort or risk.

And so it is today. When I talk about the the Primal Blueprint as the genuine design to gain health and vitality with the least amount of pain, suffering and sacrifice possible, it should be clear that this is the continuing, in progress objective. The Blueprint is not a static formula, and neither should your experience of it be.

So, how can you leverage doubt in pursuing a healthy life? Let me throw out a few takeaways and examples.

Don’t accept just anyone as an absolute “authority”

I don’t need to personally conduct my own longitudinal studies or spend years authoring large meta-studies to trust them.

That said, I can scrutinize scientific studies and/or read diverse sources that cover and discuss these studies or the health and wellness field in general. I can read each with a grain of salt, understanding that the best argument isn’t always the most insistent or entertaining. I suggest you employ the same measured skepticism as well.

Question how much any product, contraption or membership will realistically benefit your priorities and lifestyle

I don’t own much equipment, and most of my workouts don’t require a gym. That’s the beauty of Primal movement principles. Likewise, I’m skeptical of the countless new gimmicks that get rolled out every year as the latest panacea for everything under the sun.

Prioritize the basics of real food diets, Primal macro ratios, solid sleep, and essential nutrients. If a health recommendation or contraption sounds complicated, it’s probably superfluous.

Don’t underestimate the need for modification

Health practices, even as they follow general principles, still need to be tailored. Metabolic and other physiological subtleties vary from individual to individual, and we all obviously bring plenty of personal circumstances to the table that will influence what works for us and what doesn’t.

By all means, study the principles, but commit to continual self-experimentation and modification. Isolate new variables for a while, and see how increasing or decreasing carbs slightly works for you. Adjust the timing of your workouts. Try giving up nightshades for thirty days to see how you feel when you’re off of them and when you go back on. See if eating more fat or less affects your body composition, hunger or energy levels.

Likewise, consider what realistically fits your lifestyle. For example, the best health practices are, above all, the ones you actually do and maintain over time.

Never accept that you’re “done”

Not only is stagnancy a boring prospect for a healthy and fulfilling life, but it’s not a sustainable truth. The human body even under the best of circumstances changes over time, adapting to age and circumstance (e.g. athletic training, significant weight loss, stress, etc.) as well as physical events or natural shifts (e.g. pregnancy, breastfeeding and menopause).

A health routine, even if it’s Primally based, that feels perfect at 25 likely will need several adjustments by the time you’re 65. If you simply maintain the same drill for years if not decades, you’ll likely be sacrificing top level benefits. Bring a healthy dose of skepticism to your own routine. Be willing to both read and experiment further to stay in your optimal zones of fitness and nutrition.

Likewise, changes of life circumstance should cause us to reexamine our assumptions about what works best for us at any given stage. For example, those HIIT routines you’ve been doing for the last five years may not be the best strategy now that you have two kids under three and are operating on routine sleep deprivation. CrossFit may sound great (and is for many people), but ask yourself if it’s really the fitness practice you want to commit to as you just begin to reclaim your health and start getting back in shape after a ten year hiatus of exercise.

Don’t assume you need to adopt every good strategy you read about

I’ve mentioned this before, but it’s worth saying again. This blog reaches several million people a month, and readers here are working at varied levels with countless interests. In keeping with that, I cover a lot of ground in terms of strategies and information. Not all of it may be valuable or relevant to you.

I think this point is critical: be selective enough in what you take on that you don’t overwhelm yourself and lose motivation. Keep Primal living as simple as you can. Apply doubt when considering whether any additional change or routine will make enough difference to be worthwhile in this particular moment. That doesn’t mean the answer will always be no. Sometimes it will absolutely be a definite yes, and a window of experimentation can confirm as much. Regardless of our ultimate decision, doubt can ensure that we’re thoughtful about each new practice we commit to in the grand scheme of our health goals.

Thanks for reading, everyone. How has doubt helped you in your health endeavors? Share your thoughts, and have a great end to your week.

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12 Common Causes of Bloating (and How to Eliminate Them)

We’ve all been through it. You come home after a big day at the dog park, your owner pours a few cups of meaty kibble, and in your zest you can’t help but inhale the food. You chase it with a bowl-full of ice water. Sated, you try to lie down under the dining room table, but you can’t get comfortable. No position feels right. There’s something pressing on your insides. You feel like vomiting, but nothing comes out. Several dry retches later and the reality of the situation hits you: bloat. On goes the leash and you’re off to the emergency vet for a quick intervention.

Oh, wait. That’s not right. Sorry, I warged into my goldendoodle for a second. Bloat kills dogs. In humans, bloating isn’t fatal. But it is unpleasant, unattractive, and uncomfortable. It’s also difficult to pin down because it’s so nebulous. Let’s try anyway.

Bloating can manifest in a number of ways:

Gas.

Distended stomach.

Tight belts.

Gut pain.

Feeling “puffy.”

Bloating is mostly subjective. You can “feel” bloated without experiencing actual stomach bulging. Other times, it adds actual inches to your waistline.

Why does it happen? Why do our stomachs distend and our sphincters proclaim their gaseous intentions to the world? What causes this nebulous condition and how can we avoid and fix it?

1. FODMAPs

FODMAPS, aka fermentable oligosaccharides, disaccharides, monosaccharides and polyols, are short-chain carbohydrates that are supposed to be absorbed in the small intestine and utilized by the body. In most people, that’s what happens: they get digested and absorbed. In the unlucky people who have trouble digesting them, FODMAPs make it to the colon for fermentation by gut bacteria. And that’s where the trouble starts. Fermentation begets hydrogen gas, which gathers in the gut and causes great distress. Common complaints of the FODMAP intolerant are bloating, stomach pain, and visits to the toilet that are either unproductive or way too productive.

For more information on low-FODMAP diets and avoiding the most common and immediate cuases of bloating, check out Fruit Belly. It’s a great primer for avoiding bloat, particularly the kind caused by maldigestion of short-chain carbohydrates. Also see my previous post on FODMAPs for the full list of foods that contain them.

Remember the FODMAPs as you read the rest of the post. You’ll notice the FODMAPs showing up throughout this article. When it comes to bloating, they are very often involved.

See my post for ideas on how to fix your FODMAP intolerance. Because never being able to eat Brussels sprouts, garlic, onions, and stone fruit is a terrible fate.

2. Stress

Psychological stress inhibits the action of GLUT2, the transporter responsible for the small intestinal absorption of glucose, fructose, and galactose in the gut. Without GLUT2, we can’t absorb those carbs, and they’re more likely to pass through to the colon for fermentation and gas production. Stress also alters the composition and function of your gut flora, making your gut bacteria less diverse and opening up space for certain gas-producing pathogenic species to overpopulate.

Get a handle on your stress however you can. Meditation (or its alternatives), herbs and teas, anti-stress strategies, frequent nature infusions, a daily walk. Rethink it. Just do it.

3. IBS

Among IBS patients with constipation, bloating is the symptom that receives the most vociferous complaints. It seems that IBS patients have trouble getting rid of the gas they accumulate. The gas literally cannot be expelled.

Try GAPS (Gut and Psychology Syndrome) diet or SCD (specific carbohydrate diet). Finding a good health practitioner may also be important.

4. Obesity

Obesity is consistently associated with bloating. It may not be causal, exactly. Whatever causes obesity may also cause bloating. But if that’s true, fixing the obesity will likely fix the bloating, too. Plus, who wants to be obese anyway? It’s bad for your health.

Lowish-carb Primal is my preferred solution for obesity. It really gets the ball rolling and it seems to be the easiest path to follow. I’m biased, of course.

5. Wheat

Several studies identify gluten/wheat as a major bloating culprit. In Mexican adults, those who reported adverse reactions to gluten had objectively higher rates of bloating and constipation. Both the gluten itself and the short-chain carbohydrates found in wheat may pose gastrointestinal problems for susceptible people. Among some subjects, the non-gluten FODMAP components may even be the primary offenders.

Don’t eat wheat, rye, or barley.

6. Small intestinal bacterial overgrowth (SIBO)

In SIBO, the normally depopulated small intestine is overrun with bacteria. More gut bacteria should be awesome, right? Not in the small intestine. SIBO is characterized by a reduction in lactase (the enzyme that degrades lactose) and poor absorption of sorbitol (a polyol) and fructose (a monosaccharide). This allows all three short-chain carbs to pass through to the colon for unwanted fermentation and gas production.

As with IBS, a well-established protocol like GAPS (Gut and Psychology Syndrome) diet or SCD (specific carbohydrate diet) may also help against SIBO. In the meantime, try a low-FODMAP diet to eliminate the offending carbohydrates.

7. Imbalanced gut bacteria

Some gut bacteria consume carbohydrates and produce methane. Some consume them and produce hydrogen. Still others consume the gases other bacteria produce. If you have a lot of the gas-producing bacteria and few of the gas-consuming bacteria, you’re asking for bloating.

Fix your gut bacteria. I know, I know: that’s no easy feat. But I’ve written extensively on the subject, so revisit those posts for some ideas. As bacterial sequencing is still kinda spotty, use your symptoms as a guide for tracking the effectiveness of your interventions. Good thing is that feedback is fast.

8. Constipation

The inability to “go” is a potent cause of bloating. I’d argue that it’s even worse than gaseous bloating because solid things are just sitting there. They aren’t moving, they’re accumulating. And as long as you’re eating and digesting, more is always arriving. This creates a terrible bloat. A heavy bloat. A physical bloat that can’t be relieved with a few well-placed farts or burps.

Most people with chronic constipation report bloating.

Check your fiber intake. Both too much and too little can cause constipation. Explore resistant starch, prebiotics, probiotics, and fermented food. Fermented dairy (yogurt, kefir) may be of assistance.

9. Low stomach acid

Without adequate stomach acid, alkaline bacteria who’d normally be unable to establish themselves are suddenly free to set up shop. If you recall what I wrote several paragraphs back about SIBO, you’ll know that this leads to poor carbohydrate digestion and successful delivery of fermentable short-chain carbs to the colon for gas production.

Stomach acid also promotes the secretion of carb-digesting enzymes in the intestines. If stomach acid is low, those enzymes run low, too, and it’s harder to digest carbohydrates. More carbs make it through for colonic fermentation (and gas production) in the context of low stomach acid.

It could be said that bloating causes GERD, as the presence of gas in the gut can distend the stomach and exert sufficient pressure to push its acidic contents up into the esophagus.

Betaine HCL can restore stomach acidification in certain conditions. Apple cider vinegar (a couple tablespoons mixed in a cup of water) can also help here. Going low-carb, thereby reducing the amount of carbs available for fermentation, has also been shown to improve symptoms of GERD.

10. Eating and drinking too quickly

For the same reason gulping kibble can cause bloat in dogs, eating your food too quickly can cause bloating in humans: it increases the likelihood of swallowing air.

Slow down, chew your food more, take smaller bites. Don’t eat kibble.

11. A full stomach

Eating a massive meal is a great way to feel bloated. I mean, you’ve literally filled your GI tract with food.

Eat smaller meals. Eat till satiated, not until you hate yourself. If you’ve eaten a large meal, take a walk.

12. Creatine

Creatine is one of those supplements with few downsides. It just works (unless it doesn’t). But part of the reason it works can also cause perceived bloating. Creatine promotes increased intracellular water storage, or water retention. As this water isn’t available for body-wide thermal regulation—it “sticks around”—and can give the impression that you’re bloated. The evidence is quite mixed on this one, but the preponderance of anecdotes from people complaining about “creatine bloat” makes me think there’s something going on. Even if it doesn’t show up on objective tests, if you think you’re bloated, you might as well be.

Stick with it. Creatine takes some getting used to. Most “creatine bloating” is due to the increased water retention being a new sensation.

What did I miss, folks? What are the common triggers for bloating in you? How do you deal with them?

Thanks for reading, everyone!

How Much Meat Is Too Much?

I’ve discussed—and countered—many misconceptions people hold to be true about the Primal lifestyle. That we wear loin cloths and shun modern medicine (I only do one of those), eat so low-carb all the time that running our urine through a coffee filter produces valuable ketone esters (stay tuned for the supplement!), and avoid cardio to the point of scolding ourselves if we have to run to catch the train (only if we jog rather than sprint). One in particular has stuck: that we’re meat-obsessed.

This one isn’t totally unfounded. We do enjoy our bacon, our steaks, our lettuce-wrapped burgers, our legs of lamb, our roast chickens. Personally, I emphasize the animal foods (which include “meat”) for two reasons: they’re extremely nutrient-dense and they’ve gotten a terrible rap for decades. We should be eating them on a regular basis but, by and large, people are scared to. There’s always that voice in your head repeating back to you the scary “red meat will give you cancer” or “meat consumption linked to diabetes” headlines that pop up every few weeks. I consider it my job to remove the stigma of healthful animal foods, to highlight the importance and vitality of meat in the human diet.

But that doesn’t mean it’s a free for all. There are upper limits on meat intake, just as there are upper limits on everything.

Let’s ignore the outliers. The folks who really do feel better on all-meat diets and the people who insist they thrive on zero-meat diets aren’t relevant today. The people who matter are the people reading this post. People trying to lose some body fat. People following a strength training regimen. Elderly people. All the different contexts in which people find themselves can affect our upper limit of meat.

How?

Strength training

Strength training’s relationship to protein intake is a curious one. Lifting heavy things actually makes you more efficient with your protein. As long as you’re lifting, you do more with less. You can get away with eating less protein.

On the other hand, lifting weights makes higher doses of protein safer. Animal studies show that large, acute increases of protein intake can stress the renal system and cause metabolic disturbances.  Left unchecked, this is dangerous. If the animals are performing resistance training, however, the kidneys can handle larger doses of protein without issue. Humans seem better adapted to higher protein intakes (it doesn’t harm our kidneys unless they’re already damaged), but I’d imagine the protective effect of resistance training is similar.

What this means is that strength training both reduces your protein requirements and increases the amount of protein you can safely utilize. Weird, right? You can eat more, but you don’t necessarily have to.

As for the 1 gram per pound of body weight bodybuilder diets you hear about? Novices can probably benefit from higher protein intakes, as they have a higher “gains ceiling” and gain muscle fairly quickly. More experienced lifters who are closer to their ceiling and gain muscle more slowly (if at all) don’t need as much protein. 1.8 grams per kg seems to be the absolute ceiling for natural lifters. After that, the benefits level off and you’re just wasting protein.

Dieting

Dieters don’t just lose body fat. They lose lean mass, too (that’s why I like to talk about “fat loss,” not “weight loss“). Protein content of the cutting diet is a major determinant of how much lean you lose. In study after study, high protein intakes while dieting preserve lean mass and preferentially burn body fat. A 2013 study split dieters into three groups: one eating the protein RDA (0.8g/kg), one eating 2x the RDA (1.6g/kg, or about 120 grams per day), and one eating 3x the RDA (2.4g/kg, or about 185 grams per day). Fat intake was constant across all groups, and carbs filled in the rest. There were no differences in weight loss, but the two latter groups lost more body fat than lean. The group eating the RDA lost significantly more lean mass.

The more you cut calories, the more protein you need. And not in a relative sense—you need to increase your absolute protein intake to limit loss of lean muscle mass.

Age

Protein metabolism is less efficient in the elderly. The standard RDA of 0.8g/kg simply doesn’t cut it. In fact, it leads to lean mass loss, atrophy, and poor health outcomes. To attain the same metabolic outcomes you enjoy, your grandma or grandpa has to eat way more protein than you. Studies indicate that a baseline intake of 1.0-1.3 g protein/kg bodyweight or 0.5-0.6 g protein/lb bodyweight is the bare minimum for the healthy and frail elderly to ensure nitrogen balance. 160 grams of red meat per day seems to do the trick alright, but 220 grams per day might be even better! That’s grams of meat, not protein.

Injuries/bed rest

When you’re on bed rest recovering from an injury, or a burn, or surgery, you not only can handle more protein. You need more protein to get better. We use protein to rebuild damaged tissues. Collagen comes in handy here, as skin is primarily made up of collagen. One study found that in patients recovering from ulcers, collagen supplementation sped up healing time.

Bed rest increases protein upper limits. When you’re not using your muscles, when they aren’t receiving any stimulus, you’re telling your body you don’t need them. That’s a terrible message to be sending. Added protein muddles the message and reduces the breakdown of muscle tissue.

What about the problematic compounds found in meat that detractors are always highlighting? Do those determine how much meat is too much?

Let’s look at some.

Iron

Iron isn’t “bad.” Like anything else, it’s conditionally good and conditionally bad for us. Our red blood cells employ iron to help them fulfill their primary role: the delivery of oxygen to tissues and cells throughout the body. In athletes, kids, infants, and ladies with kids in their bellies, iron is particularly important. Pregnancy and development increase iron demands, as does exercise. We literally cannot live or create life without adequate amounts of iron in the diet.

But an excess of iron is bad. As an oxidant, too much iron poses major issues. Observational studies link iron intake and stored iron to diseases and disease states like type 2 diabetes, heart disease, insulin resistance, inflammation, Alzheimer’s disease, hypertension, fatty liver, hypothyroidism, arthritis, and cancer. These types of studies can’t establish causation, of course, but they’re consistent. And we know that men with iron excess who reduce it through blood donation see improved health markers, including insulin sensitivity and liver enzymes.

Iron from animal sources like beef, lamb, and organs is far more bioavailable than iron from plant sources. It’s called heme iron, and we absorb almost all of it. Only about half of non-heme iron is actually absorbed. Furthermore, many common foods, like coffee, tea, plant polyphenols, and dairy readily inhibit our absorption of plant iron. The only real way to inhibit heme iron is to eat large amounts of calcium alongside it.

A 100 gram portion of ground beef contains 2.6 mg of heme iron.

100 grams of chicken has 1.3 mg.

100 grams of beef liver has 4.9 mg.

100 grams of chicken liver has 9 mg.

The recommended daily intake of iron is 9 mg per day for men, 18 for menstruating women. For pregnant women, it’s 27 mg. However, that presupposes that most of the iron you eat isn’t very bioavailable (remember the absorption inhibition). Many common foods and drinks, like coffee, tea, polyphenols, and calcium, reduce non-heme iron absorption. Many people get their iron through plant foods and fortified grains, so they aren’t absorbing all the iron they’re eating. People who get most of their iron through meat probably need less than 18 or 27 mg because they are absorbing most of the iron they’re eating.

Kids, teens, tots, infants? Don’t worry about eating too much iron in meat. I don’t want to see any 15 month olds freaking out about the heme iron content in the incomprehensible meat-mush caked across their faces.

Pregnant ladies? “Too much iron” should not be a factor when considering how much meat to eat.

Men and post-menopausal women? Monitor your ferritin levels and see how meat affects it. A 40-60 range might be ideal, as drops in insulin sensitivity have been seen at slightly higher levels, but that figure isn’t set in stone.

If you have hereditary hemochromatosis, an iron-storage disorder characterized by high iron accumulation, limit high-iron meat. Track your ferritin levels (you’re probably already doing this). You can still eat red meat, just be mindful of its effect on your iron levels and adjust intake accordingly.

Methionine

Methionine is an essential amino acid, meaning we can’t synthesize it and must obtain it from the diet. It’s most abundant in animal foods, particularly meat (and egg whites). The “calorie restriction for longevity” crowd has zeroed in on methionine as the big dietary baddie in the fight against physical death, citing tons of animal studies in which methionine excess spikes homocysteine levels and reduces lifespan.

Methionine processing occurs in the liver and depletes several key nutrients: choline, betaine, folate, and glycine. You need ample amounts of those nutrients to make methionine—and meat—safer.

If you’re not eating egg yolks (choline and betaine), spinach (betaine), liver and greens (folate), and collagen-rich meats and supplements (glycine), your upper limit of muscle meat is probably lower. If you are eating those foods, you can get away with more meat.

Okay, okay. Got any numbers, Sisson?

Start with about a pound of meat a day, give or take a few ounces. Depending on what type of meat you’re eating, that’ll give you about 85-90 grams of protein. Additional protein from other foods (dairy, eggs, nuts, seeds) should put you in the realm of 100-120 grams of protein. That’s where I am most days—between 100 and 120 grams of protein. It’s a good place to start.

If you’re older, on bed rest, dieting, you can safely eat more.

If you’re lifting, you don’t have to eat more but may want to.

Eating a greater proportion of gelatin, either supplementarily, via delicious chocolate almond bars, or by favoring gelatinous meats (skin, cartilage, shanks, necks, oxtails) and drinking bone broth, will increase your safe upper limit of meat.

Monitoring your ferritin levels will allow you to identify your safe upper limit.

Still worried? “Meat” doesn’t have to be red meat, or even terrestrial meat. You can—and should—mix it up with fish, shellfish, cephalopods, birds, even insects.

There are no hard and fast answers. There is no single number that’s right for everyone. It depends on many factors. In biology, that’s typically the case. But hopefully, you feel equipped to tailor your meat consumption to your personal context.

So: do you? Let me know how this post resonates with you. If you have any further questions about upper intakes of meat, let me know down below!

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How Much Meat is Too Much?

I’ve discussed—and countered—many misconceptions people hold to be true about the Primal lifestyle. That we wear loin cloths and shun modern medicine (I only do one of those), eat so low-carb all the time that running our urine through a coffee filter produces valuable ketone esters (stay tuned for the supplement!), and avoid cardio to the point of scolding ourselves if we have to run to catch the train (only if we jog rather than sprint). One in particular has stuck: that we’re meat-obsessed.

This one isn’t totally unfounded. We do enjoy our bacon, our steaks, our lettuce-wrapped burgers, our legs of lamb, our roast chickens. Personally, I emphasize the animal foods (which include “meat”) for two reasons: they’re extremely nutrient-dense and they’ve gotten a terrible rap for decades. We should be eating them on a regular basis but, by and large, people are scared to. There’s always that voice in your head repeating back to you the scary “red meat will give you cancer” or “meat consumption linked to diabetes” headlines that pop up every few weeks. I consider it my job to remove the stigma of healthful animal foods, to highlight the importance and vitality of meat in the human diet.

But that doesn’t mean it’s a free for all. There are upper limits on meat intake, just as there are upper limits on everything.

Let’s ignore the outliers. The folks who really do feel better on all-meat diets and the people who insist they thrive on zero-meat diets aren’t relevant today. The people who matter are the people reading this post. People trying to lose some body fat. People following a strength training regimen. Elderly people. All the different contexts in which people find themselves can affect our upper limit of meat.

How?

Strength training

Strength training’s relationship to protein intake is a curious one. Lifting heavy things actually makes you more efficient with your protein. As long as you’re lifting, you do more with less. You can get away with eating less protein.

On the other hand, lifting weights makes higher doses of protein safer. Animal studies show that large, acute increases of protein intake can stress the renal system and cause metabolic disturbances.  Left unchecked, this is dangerous. If the animals are performing resistance training, however, the kidneys can handle larger doses of protein without issue. Humans seem better adapted to higher protein intakes (it doesn’t harm our kidneys unless they’re already damaged), but I’d imagine the protective effect of resistance training is similar.

What this means is that strength training both reduces your protein requirements and increases the amount of protein you can safely utilize. Weird, right? You can eat more, but you don’t necessarily have to.

As for the 1 gram per pound of body weight bodybuilder diets you hear about? Novices can probably benefit from higher protein intakes, as they have a higher “gains ceiling” and gain muscle fairly quickly. More experienced lifters who are closer to their ceiling and gain muscle more slowly (if at all) don’t need as much protein. 1.8 grams per kg seems to be the absolute ceiling for natural lifters. After that, the benefits level off and you’re just wasting protein.

Dieting

Dieters don’t just lose body fat. They lose lean mass, too (that’s why I like to talk about “fat loss,” not “weight loss“). Protein content of the cutting diet is a major determinant of how much lean you lose. In study after study, high protein intakes while dieting preserve lean mass and preferentially burn body fat. A 2013 study split dieters into three groups: one eating the protein RDA (0.8g/kg), one eating 2x the RDA (1.6g/kg, or about 120 grams per day), and one eating 3x the RDA (2.4g/kg, or about 185 grams per day). Fat intake was constant across all groups, and carbs filled in the rest. There were no differences in weight loss, but the two latter groups lost more body fat than lean. The group eating the RDA lost significantly more lean mass.

The more you cut calories, the more protein you need. And not in a relative sense—you need to increase your absolute protein intake to limit loss of lean muscle mass.

Age

Protein metabolism is less efficient in the elderly. The standard RDA of 0.8g/kg simply doesn’t cut it. In fact, it leads to lean mass loss, atrophy, and poor health outcomes. To attain the same metabolic outcomes you enjoy, your grandma or grandpa has to eat way more protein than you. Studies indicate that a baseline intake of 1.0-1.3 g protein/kg bodyweight or 0.5-0.6 g protein/lb bodyweight is the bare minimum for the healthy and frail elderly to ensure nitrogen balance. 160 grams of red meat per day seems to do the trick alright, but 220 grams per day might be even better! That’s grams of meat, not protein.

Injuries/bed rest

When you’re on bed rest recovering from an injury, or a burn, or surgery, you not only can handle more protein. You need more protein to get better. We use protein to rebuild damaged tissues. Collagen comes in handy here, as skin is primarily made up of collagen. One study found that in patients recovering from ulcers, collagen supplementation sped up healing time.

Bed rest increases protein upper limits. When you’re not using your muscles, when they aren’t receiving any stimulus, you’re telling your body you don’t need them. That’s a terrible message to be sending. Added protein muddles the message and reduces the breakdown of muscle tissue.

What about the problematic compounds found in meat that detractors are always highlighting? Do those determine how much meat is too much?

Let’s look at some.

Iron

Iron isn’t “bad.” Like anything else, it’s conditionally good and conditionally bad for us. Our red blood cells employ iron to help them fulfill their primary role: the delivery of oxygen to tissues and cells throughout the body. In athletes, kids, infants, and ladies with kids in their bellies, iron is particularly important. Pregnancy and development increase iron demands, as does exercise. We literally cannot live or create life without adequate amounts of iron in the diet.

But an excess of iron is bad. As an oxidant, too much iron poses major issues. Observational studies link iron intake and stored iron to diseases and disease states like type 2 diabetes, heart disease, insulin resistance, inflammation, Alzheimer’s disease, hypertension, fatty liver, hypothyroidism, arthritis, and cancer. These types of studies can’t establish causation, of course, but they’re consistent. And we know that men with iron excess who reduce it through blood donation see improved health markers, including insulin sensitivity and liver enzymes.

Iron from animal sources like beef, lamb, and organs is far more bioavailable than iron from plant sources. It’s called heme iron, and we absorb almost all of it. Only about half of non-heme iron is actually absorbed. Furthermore, many common foods, like coffee, tea, plant polyphenols, and dairy readily inhibit our absorption of plant iron. The only real way to inhibit heme iron is to eat large amounts of calcium alongside it.

A 100 gram portion of ground beef contains 2.6 mg of heme iron.

100 grams of chicken has 1.3 mg.

100 grams of beef liver has 4.9 mg.

100 grams of chicken liver has 9 mg.

The recommended daily intake of iron is 9 mg per day for men, 18 for menstruating women. For pregnant women, it’s 27 mg. However, that presupposes that most of the iron you eat isn’t very bioavailable (remember the absorption inhibition). Many common foods and drinks, like coffee, tea, polyphenols, and calcium, reduce non-heme iron absorption. Many people get their iron through plant foods and fortified grains, so they aren’t absorbing all the iron they’re eating. People who get most of their iron through meat probably need less than 18 or 27 mg because they are absorbing most of the iron they’re eating.

Kids, teens, tots, infants? Don’t worry about eating too much iron in meat. I don’t want to see any 15 month olds freaking out about the heme iron content in the incomprehensible meat-mush caked across their faces.

Pregnant ladies? “Too much iron” should not be a factor when considering how much meat to eat.

Men and post-menopausal women? Monitor your ferritin levels and see how meat affects it. A 40-60 range might be ideal, as drops in insulin sensitivity have been seen at slightly higher levels, but that figure isn’t set in stone.

If you have hereditary hemochromatosis, an iron-storage disorder characterized by high iron accumulation, limit high-iron meat. Track your ferritin levels (you’re probably already doing this). You can still eat red meat, just be mindful of its effect on your iron levels and adjust intake accordingly.

Methionine

Methionine is an essential amino acid, meaning we can’t synthesize it and must obtain it from the diet. It’s most abundant in animal foods, particularly meat (and egg whites). The “calorie restriction for longevity” crowd has zeroed in on methionine as the big dietary baddie in the fight against physical death, citing tons of animal studies in which methionine excess spikes homocysteine levels and reduces lifespan.

Methionine processing occurs in the liver and depletes several key nutrients: choline, betaine, folate, and glycine. You need ample amounts of those nutrients to make methionine—and meat—safer.

If you’re not eating egg yolks (choline and betaine), spinach (betaine), liver and greens (folate), and collagen-rich meats and supplements (glycine), your upper limit of muscle meat is probably lower. If you are eating those foods, you can get away with more meat.

Okay, okay. Got any numbers, Sisson?

Start with about a pound of meat a day, give or take a few ounces. Depending on what type of meat you’re eating, that’ll give you about 85-90 grams of protein. Additional protein from other foods (dairy, eggs, nuts, seeds) should put you in the realm of 100-120 grams of protein. That’s where I am most days—between 100 and 120 grams of protein. It’s a good place to start.

If you’re older, on bed rest, dieting, you can safely eat more.

If you’re lifting, you don’t have to eat more but may want to.

Eating a greater proportion of gelatin, either supplementarily, via delicious chocolate almond bars, or by favoring gelatinous meats (skin, cartilage, shanks, necks, oxtails) and drinking bone broth, will increase your safe upper limit of meat.

Monitoring your ferritin levels will allow you to identify your safe upper limit.

Still worried? “Meat” doesn’t have to be red meat, or even terrestrial meat. You can—and should—mix it up with fish, shellfish, cephalopods, birds, even insects.

There are no hard and fast answers. There is no single number that’s right for everyone. It depends on many factors. In biology, that’s typically the case. But hopefully, you feel equipped to tailor your meat consumption to your personal context.

So: do you? Let me know how this post resonates with you. If you have any further questions about upper intakes of meat, let me know down below!

Dear Mark: Dairy Inhibiting Magnesium Absorption, Trampoline Training, and Max Aerobic Heart Rate

For today’s edition of Dear Mark, I’m answering three questions. First, does dairy inhibit magnesium absorption, thus negating the utility of adding blackstrap molasses to milk? There’s a good deal of evidence that points to a probable answer. Next, is mini trampoline training actually good for you, or is it just a silly way to pass the time and look ridiculous (or all of the above)? And finally, how should someone calculate (and train under) their max aerobic heart rate?

Let’s go:

Hi mark, in regards to your recent post and another previous post about blackstrap molasses and some suggestions to how it can be taken, you mention a couple of ways that include dairy.

I have read that the absorbtion of magnesium is affected (decreased) when taken with dairy, I was wondering if there was any truth behind this and if so to what degree?

Thanks!

Dan

I’ve heard that too but never saw it substantiated. You spend enough time in alternative health circles and it starts to seem like dairy inhibits the absorption of everything. The calcium content of dairy blocks iron absorption. The dairy protein prevents you from absorbing the polyphenols in blueberries. Dairy supposedly even prevents you from absorbing the calcium it contains, if you listen to the more rabid of the vegans.

So, does dairy inhibit magnesium absorption, as the Weston A Price Foundation has asserted?

Lactose doesn’t block magnesium absorption. A study in live healthy human subjects found that the presence of lactose, even in large amounts, had no effect on magnesium absorption.

Calcium doesn’t block magnesium absorption. The body uses separate pathways to absorb each. The biggest determinant of magnesium bioavailability is your magnesium status. If you’re low, absorption is high. If you’re replete, absorption drops. It’s totally context-dependent.

Casein doesn’t block magnesium absorption. Researchers actually use casein as the control when studying the effects of various proteins on magnesium bioavailability.

I don’t see any route by which dairy would block magnesium absorption. Have at it!

What is your opinion of exercising on a rebounder or mini trampoline? There doesn’t seem to be much research. But webpages and blogs all report glowing benefits. The only research that all sites use is a NASA report about how beneficial rebounding is for returning astronauts. What are your thoughts?

I’ve actually seen a decent amount of research. I’ll go through some of it and then give my thoughts after.

A group of Thai working women performed aerobic dance moves on a hard wooden surface or mini trampoline. Both produced good training effects and improved bone metabolic parameters, but the trampoline produced more leg strength and forced better balance.

A moderate intensity exercise session on a mini trampoline has the ameliorative effect on blood glucose you’d expect.

In patients recovering from a stroke, mini trampoline training improved postural control to a greater degree than balance training. It also led to greater improvements in daily functioning and mobility. Another study in stroke patients found that trampoline training (30 minutes a day, 3 times a week for 6 weeks) led to fewer falls, greater balance, and improved gait.

In elderly women, trampoline training ranks among the best ways to improve balance (and thus reduce falls and catastrophic injuries).

In athletes with ankle instability, training on a mini trampoline improves postural control and reduces sway.

There’s evidence it’s not just good for the elderly and health-compromised. In a group of male gymnasts, training on a mini trampoline for 12 weeks improved sprint speed, standing broad jump, vertical leap, and anaerobic power output.

They’re a little risky, too, particularly the big backyard ones. If you’re going to bounce around on a trampoline, observing the following rules seems to minimize the risk of injury:

Bounce alone. One at a time, please. Most injuries involve collisions with other people.
Don’t jump off of an elevated surface onto the trampoline. Roof to trampoline, bad. Trampoline to roof, awesome (if you can pull it off, but you may need to be a comic book character).
Use a safety net to prevent falls.

Most importantly, trampolines are fun. I have fond childhood memories of bouncing on my buddy’s backyard trampoline. We were reckless, of course, which I wouldn’t recommend. We probably got lucky. But man was it fun.

Dear Mark,

I must precede my question with a tremendous note of gratitude. I am a fitness trainer and health coach, age 67, and having followed the advice of “Primal Blueprint” and “Primal Endurance”, I’ve gone from 18.3% body fat to 12.3% body fat in 4 months. I feel much better, am stronger and faster, and suffer much less injuries. Before I met you, I was overtraining junky that would yoyo between peaks and painful setbacks. God bless you, Mark, and thanks ever so much.

Here’s my question:

According to various calculations, my heart-rate max should be somewhere between 153 – 161. My HR at rest is about 68 (here in hot Israeli summers). Yet, I jog at 153, run at 180, and at all-out sprints can hit as high as 212. Understandably, I’m confused as how to stay in my aerobic zone. What we be your recommendation.

A million thanks and blessings for your continued success,

Lazer from Israel

Using the Maffetone method outlined in Primal Endurance, you calculate your max aerobic heart rate by subtracting your age from 180. That gives you 113. It means in order to maximize fat burning and minimize sugar burning, you have to keep your heart rate at or under 113 during exercise. It doesn’t sound like much. It probably feels way too easy. But bear with me. It works. This is where the magic happens, where you accumulate easy volume, where the “base” is built, where you begin building more fat-burning mitochondria. It probably feels way too easy, especially for a guy like you with so much experience.

The hard truth: if jogging spikes your heart rate past your aerobic max, you’re not very good at burning fat during exercise. Even if you don’t “mind” pushing that heart rate up. Even if you “feel fine” jogging at 153 bpm. 180 minus age is where you have to be to improve fat burning.

You might be awesome at burning sugar all day at a much higher HR, and even feel quite comfortable for long periods of time (until you burn out), but you will not be improving your fat-burning efficiency if you simply keep doing that. Most endurance athletes find that high-end sugar-burning HR zone and get “comfortable” in it several times a week, but then never really improve race speed (read: efficiency) from that point. It takes patience to stay at the aerobic zone, but over time everyone notices that they are able to handle a higher and higher work load at that rate, which means that you are going faster while still burning mostly fat.

If you’re just interested in immediate objective performance results—fast times, feeling like you “did something” after every training session—keep at it. Just know that you will be undercutting lasting benefits to your fat-burning efficiency, boosts to your fitness, and improvements in your long term health trajectory. You know where I stand on this one.

Thanks for reading, everyone!

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