The idea that vegetables are an essential part of a healthy diet has been hammered into our collective consciousness by every authority out there. Parents, teachers, scientists, government health “experts” all stress the importance of eating your veggies. Problem is, they also told us that butter would kill us, margarine would save us, animal protein would give us cancer, and animal fat would give us heart disease. They said we should jog for an hour a day three days a week, that deadlifts would hurt our backs, and that we need to wear shoes with “good arch support.”
Basically, conventional wisdom gets it wrong an awful lot of the time, so what should we think about the conventional wisdom regarding vegetables? It’s a fairly common query I receive from readers, especially since the rise of the carnivore movement:
Do you really need to eat vegetables—or plant matter in general—to be healthy?
Let’s get straight into it.
Do You Need To Eat Vegetables to be Healthy?
I know I’m inviting the wrath of my carnivore followers here, but:
Yes. Yes, you do. Not a huge amount necessarily, but you do need some.
I’m well aware that there are some people out there who have apparently thrived for months or years on a meat-only diet. I’m not saying it’s not possible. I’m saying that for most people, it’s probably not optimal for reasons I’ll discuss in this post.
With that quick answer out of the way, allow me to address some of the pertinent questions and assertions I receive from readers.
“What about the traditional cultures that ate little to no plants or vegetables and were healthy? Like…”
The Inuit – While they ate a high-fat, high-protein, low-carb diet consisting of the fat and meat from seal, walrus, whale, caribou, fish, and other wild game, 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.12
The Maasai – Milk, meat, and blood are the high-fat, low-carb staples of the traditional Maasai diet, particularly that of the male warriors. But it’s not all they eat. The Maasai often trade for plant foods like bananas, yams, and taro, too, and they cook their meat with anti-parasitic spices, drink bitter (read: tannin- and polyphenol-rich) herb tea on a regular basis, and used dozens of plants as medicines.3
The Sami – Reindeer herders of the Scandinavian north, the Sami people eat a low-carb, high-protein, high-fat diet of meat, fish, and reindeer milk. They 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!4), sometimes even feeding their reindeer hallucinogenic mushrooms to produce psychoactive urine.
Bottom line: Plants played important roles in every traditional human diet we know about. Not as a source of calories, necessarily, but as a source of micronutrients, plant polyphenols, and medicinal compounds.
“Animal foods provide all the micronutrients a person needs.”
Animal products include some of the most nutrient-dense foods available. They’re our best (and often only) source of vitamin A (retinol), DHA/EPA, and vitamin B12, as well as lesser-known nutrients like choline, creatine, and carnosine. But a diet devoid of vegetables and other plants will likely be a little low in certain nutrients that we need. Like:
Potassium – Important electrolyte and regulator of blood pressure. The best sources are avocados, leafy greens, citrus fruits, and bananas. Meat contains potassium, but you have to capture the juices to get it.
Magnesium – Involved in hundreds of crucial physiological functions. The best sources are leafy greens like spinach and chard.
It’s also easy to miss out on nutrients like folate (if you don’t eat offal) and calcium (if you don’t eat dairy or small bony fish).
Plus, and this is an important point, we evolved eating wild animals. Wild animal meat and fat comes loaded with antioxidant compounds from all the wild plant matter they eat. Grass-fed beef (the more easily attainable alternative to wild meat) is higher in certain nutrients, vitamin precursors, and has a more favorable fatty acid profile compared to grain-fed.5Unless you’re hunting game or eating exclusively grass-fed beef—and using the whole animal, not just the muscle meat—consuming vegetables, herbs, and spices with your meal will help emulate the ancestral steak dinner.
“What about people who just hate vegetables? Shouldn’t we listen to our instincts?”
I have a sneaking suspicion that the ability to sense nutrients noted in many animal species is also present in humans. Like how salt-deficient cattle will gravitate toward the salt lick, maybe some people just don’t need that extra hormetic stimulus provided by the plant. Their bodies are letting them know by making vegetables taste bad. Maybe they’re so darn optimal that they only require the basic vitamins, minerals, and macronutrients to maintain their health.
But at least some of your taste preferences have to do with what you were exposed to in childhood and even earlier. Research suggests that what your mother ate while she was pregnant affected your tastes.6 If your parents hated vegetables and never served them at dinner, you’re probably less likely to embrace them as an adult. Maybe you just don’t know how to cook vegetables to make them taste good. In any case, if preferences can be learned, they can also be unlearned.
This isn’t to say you can’t genuinely dislike the taste of vegetables. We evolved in an environment when little mistakes could be very costly. Eating the wrong plant, or the wrong part of the wrong plant, might destroy your liver or drop you dead on the spot. As a result, we’re subconsciously hypersensitive to tastes, especially the bitterness characteristic of some phytonutrients, that may signal danger. People known as “supertasters” are particularly sensitive to the bitter compounds and generally eat fewer plant foods as a result.7 Your distaste for bitter plant toxins might be an adaptation from the days when some of the available plant food was too dense in toxins/phytonutrients for regular consumption—an adaptive holdover that prevents us from enjoying the healthy, hormetic, moderate levels of plant toxins in modern-day cultivated plants.
Reasons to Eat Vegetables
While I don’t think anyone needs to eat a ton of vegetables to be healthy—and I’m no fan of diets composed solely of plant foods—I do see compelling reasons for including some plant matter in your meals.
Plants complement meat
They make meat taste better. Herbs and spices make meat healthier by preventing the formation of carcinogens during cooking when you incorporate them into marinades, and vegetables reduce the impact of those harmful compounds when you consume them alongside meat. Cruciferous vegetables are a classic example. That broccoli you’re eating with your steak contains phytonutrients that reduce the potential mutagenicity (cancer-causing properties) of heterocyclic amines in well-done meat.8
I’ve questioned the merits of insoluble fiber-driven fecal hypertrophy in the past, and I remain puzzled at the relentless pursuit of fiber via whole grains. But I strongly support the consumption of fermentable fiber, the kind that feeds the microbes living in your gut and supports a healthy intestinal ecology.
If you’re convinced of the importance of a healthy gut microbiome populated with happy, vibrant gut flora —and you should be by now—you can’t ignore their food requirements. The best source of fermentable fiber is plants.
Free radicals and the damage they cause are inescapable facts of life. Antioxidants’ role is to mitigate free radical assaults that lead to disease and premature aging. Animal foods can provide some antioxidants, and some the body makes itself, but plants are the best antioxidant food sources.
Because you enjoy them
In the absence of any obvious ill effects, this reason is as good as any. Yes, any of my long-time readers know about antinutrients like phytates in certain plants, and yes, eliminating certain plants from one’s diet can sometimes alleviate symptoms of autoimmune conditions and other maladies. But if you feel great eating a lot of plants, if sitting down to a giant salad brings a smile to your face, if the thought of a meat-only diet brings on a wave of ennui, then by all means, continue to enjoy eating vegetables.
I still like vegetables even though I eat less of them than I used to. They provide textural and flavor variety that is missing from purely carnivorous fare. And they are a good vehicle for delicious salad dressings (although the same could be said of meat).
My Current Approach to Vegetable Intake
Big-ass salads used to be a daily staple, but in recent years, meat or eggs constitute the centerpiece of my meals. For me, vegetables have become an accompaniment, a side player, not the main event. I didn’t set out to change my habits deliberately. This change was the product of slow evolution resulting from listening to my body. And what my body said was that it felt better eating more protein.
Just because I eat a certain way doesn’t mean you have to, though. I’d encourage you to similarly listen to your body when determining your relative meat-to-vegetable intake. This might be something that changes day by day, week by week, or season by season. I tend to eat a greater variety of vegetables, and more vegetable matter overall, in the summer when the freshest options abound. But here are a couple guidelines I’d recommend for everyone:
Eat vegetables, but do not consider them a calorie source unless you’re talking about roots, tubers, or other starchy vegetables like pumpkin. Above-ground non-starchy vegetables are mostly fiber, water, and compounds your body doesn’t use to generate energy.
Protein takes precedence in terms of importance. If vegetables are reducing your ability to get enough protein, reduce vegetable intake.
The Bottom Line
If you hate veggies and refuse to eat them, fine. You can get most minerals and vitamins elsewhere (though it’s tough, and some spinach would take care of most of them). Using supplements is an option. But if I were you, I would at least strongly consider drinking tea or coffee, eating phytonutrient-rich fruits like berries, eating phytonutrient-rich legume extracts like dark chocolate, and using lots of different spices and herbs in your cooking. These won’t have a large carb load, but they will offer nutrients you simply can’t obtain from animals—and they provide the largest plant bang for your buck.
Before you throw in the towel, though, be sure to try lots of different plants. There are thousands of edible and medicinal ones out there, with tens of thousands of recipes and preparations available. You’ll find something you like if you keep looking.
What does everyone else think? Can you be truly healthy without including plants, particularly veggies, in your diet?
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.