Flexibility is generally a positive attribute. While I would never suggest being flexible in matters of morals, loyalty, or self-dignity, in most other areas it is beneficial.
A person should have flexible joints — they should be able to move with fluidity and grace through many different positions, under load and unloaded.
A person should have metabolic flexibility — they should be able to utilize all forms of caloric energy coming in, regardless of macronutrient ratios.
A person should be a flexible dieter — they should be able to move through life without rigid adherence to some dietary prescription resembling dogmatism. Same goes for fitness dogma.
There are many reasons why this is the case. There are a lot of different foods out there, and to sample them brings pleasure and variety. A flexible eater is someone who can roll with the punches, adapt to different situations, and eat suboptimal foods without incurring any real damage. It gives you more freedom and resiliency.
I’ve spoken of metabolic flexibility, that metabolic region where you’re going in and out of ketosis without effort, eating some carbs here and there if the opportunity presents and effortlessly slipping back into ketosis afterwards. Being in the keto zone gives a person access to the benefits from ketones, fatty acids, and carbohydrates to use as needed. It reduces the stress of strictness while retaining most of the benefits.
Carnivore: Fringe to Mainstream
The carnivore movement has really changed and grown. Back when I first encountered it, carnivore or “zero carb” as it was known was a fringe movement. People were pretty much eating ground beef and drinking water, with few exceptions. I wrote about it back in 2010 and was highly skeptical. As it’s grown, and the anecdotes and (to a limited extent) studies have accumulated, I revisited it.
I developed the Primal Blueprint as a way to beat the ailments I’d wrought with my chronic cardio, high stress endurance athletic lifestyle: IBS, arthritis, chronic upper respiratory tract infections, general lethargy. Something wasn’t right, I knew. Humans weren’t supposed to be sick and in pain all the time. It worked, I got better, and I never looked back.
Meanwhile, carnivore adherents and enthusiasts were using the diet to beat many of the same ailments I’d beaten with Primal. What was going on?
I had to explore it myself. I had to experiment, so I began incorporating many carnivore principles into my own diet. Eating more meat and other animal foods. Emphasizing protein. Eating fewer vegetables. Choosing my plants with anti-nutrients in mind. But I’m not eating only animal products. I can’t call myself a carnivore, so what am I? What is this way of eating?
Since things need names, I’m calling it Carniflex: an animal-food-centric way of eating that doesn’t eliminate plants, instead selecting for the most optimal plants.
This is fairly close to how I eat most days, and it’s actually not far from how I’ve eaten for many years.
What is Carniflex?
Like I said, I don’t want to be dogmatic about ways of eating. So these aren’t hardline “diet rules.” These are loose guideposts.
Animal foods form the basis of my diet. They provide the most calories.
Meat: steaks, burgers, chops, roasts
Seafood: fish, shellfish, shrimp
Dairy: kefir, yogurt, cheese, cream
In other words, the bulk of my diet is standard carnivorous fare.
I round out meals with vegetables and plant foods, rather than focusing on them. These foods aren’t the base of my diet. Carniflex uses plants as medicinal accoutrements. They enhance and provide micronutrition rather than huge caloric boluses.
I still have a Big Ass Salad quite often. I still have steamed broccoli dipped in butter. I still like berries and other fruits. I don’t shy away from roasted potatoes or a purple sweet potato with lemon turmeric vinaigrette, or butter and cinnamon.
Romaine lettuce. Great source of folate (a tough nutrient for many carnivores, especially those who avoid organ meats), very low in oxalates, an anti-nutrient that would compel carnivore dieters to avoid leafy greens
Fermented veggies. Fermentation and pickling reduce oxalates in vegetables like beets as well as increase the formation of probiotic bacteria
Cruciferous vegetables. Of all the standard vegetables, the cruciferous family has one of the longest histories of human cultivation and consumption. From cabbage to broccoli to cauliflower to kale. Yes, even kale, which is actually low in oxalates when cooked and whose consumption was so common in medieval Scotland that gardens were called “kail-yards.” I’m not suggesting you eat pounds of broccoli or kale. I’m suggesting that a little sauerkraut and roasted cauliflower aren’t going to hurt most people.
Alliums. Garlic, onions, and shallots are also some of the oldest cultivated vegetables, and they’re one of the best-studied. Long history of successful consumption by pretty much every cuisine on earth with modern research in support.
Colorful produce. Blueberries, blackberries, purple sweet potatoes, cherries. I’ve heard the arguments against polyphenols, that those plant polyphenol-induced hormetic pathways aren’t necessary for human health, that hard exercise and fasting and cold exposure and the myriad other environmental stressors provide all the hormetic input we need. I’m just not convinced. The literature surrounding consumption of blueberries, purple sweet potatoes, and the like is quite compelling. They do seem to provide special benefits to humans.
Clean starches. I’ve always said that clean starches like sweet potatoes, white potatoes, winter squash, and even white rice are acceptable sources of exogenous glucose for those who need or want glucose. They have none of the potential downsides of grains and legumes carnivores are trying to avoid, like unwanted fiber or anti nutrients that impair gut health. They are, for the most part, a source of starch for glycogen repletion and, in the case of sweet potatoes, squash, and potatoes, micronutrients.
Avocado, olive, coconut products. The “fruit” oils and products are not like other “plant oils.” They have superior fatty acid profiles, leaning heavily toward MUFA and SFA. They have a long history of use by people, and they can be processed with primitive technology. All you need to extract oil from a coconut, an avocado, or an olive is a mechanical press.
Fruit. Fruit “wants” to be eaten. If an animal doesn’t eat the fruit, the plant can’t disseminate its seeds. It’s in the plant’s best interest not to festoon its fruit with harmful anti nutrients that dissuade consumption and damage the consumer. The best argument against fruit in the modern human diet is that it’s been bred for sweetness and caloric density, not nutrition. But you can get around that issue by consuming less fruit, or by consuming fruit in the context of hard glycogen-depleting training—so the sugar as somewhere “to go.”
If that looks like a huge list, it’s really not. These are options. Choices you can make from meal to meal, not foods you must include every day.
But isn’t carnivore supposed to be strict?
First, strictness for strictness’ sake is a recipe for failure. If you’re working on discipline, there are ways to do it outside of what you’re eating.
Second, I had a lot of the ailments people are fixing with strict carnivore, like IBS and arthritis. I fixed them by eating like this, plants included. To me, the biggest factors are grains, seed oils, and excessive amounts of insoluble fiber. Of course, the more dire your situation, the stricter and perhaps more carnivorous you have to be.
My point in all this is that a strict carnivore diet might not be required, and I suspect it’s probably not the optimal way for most people to eat. And I think you can get most of the benefits while still incorporating plants in a smart, judicious way.
People have accused me in the past of picking and choosing what I like from different schools of thought and diet, that I’m “cheating” by agreeing with good arguments from otherwise disparate camps. To that I say: Hell yes I am.
This is the human way. We learn from other people. We develop culturally, not just genetically. We evolve within lifetimes, not only across generations. The power to do this gave humans supremacy over the world itself, and I fully intend to continue exercising it.
Carniflex is just the way that works for me. It’s something to keep in mind, something to try. And besides, I suspect many of you were already eating this way by default.
Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.