Are Carbs Bad?

The Ancestral Paradigm

Many whole-food diets are based on the paradigm of ancestral health – we should eat as our ancient, prehistoric ancestors ate.  This criteria has been explicitly invoked by Paleo and Primal diet enthusiasts, and at least implicitly invoked by followers of low-carb, Atkins, keto, and carnivore diets (as well as promoters of diets I would not recommend, such as whole food plant-based, vegetarian, and even vegan diets).

While not all of these diets are explicitly low-carb (such as Paleo, which gives no specific macronutrient suggestions), many of them are.  This seems to imply that we should all be on a very-low carb diet, that a low-carb diet is the most ancestrally appropriate diet across the board, or that carbohydrates themselves are inherently bad for humans.  Critics are quick to point out that there are human societies alive today who eat a diet of primarily plant foods, with more than half of their calories coming from carbohydrates, yet are lean and metabolically healthy, such as  the indigenous people of Papua New Guinea and the Hadza tribe. Other traditional, albeit not hunter-gatherer societies eat a lot of carbs and are still way healthier than Americans.  What gives?  Are carbs good or bad?

What Did Ancient Humans Actually Eat?

So, for a start, what did ancient humans actually eat?  The short answer is, it depends.  There is a lot of variety, but also a lot of things they all had in common:

• There is extensive archeological evidence that, prior to the invention of agriculture, humans certainly ate meat and hunted extensively; most nitrogen-isotope samples indicate that humans were as high (or higher) up the food chain than dedicated carnivores like foxes and big cats. Still, there is also evidence that most of these human populations ate a variety of plant foods, sometimes in significant quantities.

• When Weston A. Price, an American dentist, noticed all the way back in the 1930s that his patients were getting sicker and sicker, he decided that a modern Western diet was largely to blame and decided to make a survey of what traditional societies (both hunter-gatherers and agriculturalists) ate.  He noticed that traditional cultures around the world were all remarkably healthy eating a wide variety of diets.  None ate modern processed food, and all ate some animal products, but some ate a lot of carbs while others ate less carbs and a lot of meat.

• As Loren Cordain discovered, most modern hunter-gatherers eat a variety of both plants and animals, but preferentially eat meat, and tend, on average, to eat less carbohydrate, more fat, and more protein than most conventional health sources recommend. Still there are some modern hunter-gatherers (such as the Hadza) who eat mostly carbohydrates (perhaps as much as 65% of their calories) and mostly lean meat (reducing fat to a mere 11% of their calories).

Finally, keep in mind that people living an ancestral lifestyle tended to be quite healthy.  While average life expectancy was lower than today, much of this was due to infant mortality, violent deaths, and infectious diseases which can now be prevented by better hygiene and antibiotics.  Living into old age was still fairly common in these societies, and the rate of chronic diseases such as obesity, diabetes, heart disease, and cancer were still low.

Common Elements – and Key Differences – among Ancient Human Diets

What do these diets all have in common?

• All contained some animal food – none were vegetarian or vegan.

• Carbohydrate content varied widely, but none relied on the modern staples of the Western diet – refined sugar and flour.  

• None contained any processed or prepackaged foods to significant degrees.

• All of them were combined with a low-stress, active lifestyle.

In terms of differences: While Cordain indicated that hunter-gatherers tended to prefer meat to plant foods, the macronutrient profiles of these diets varied quite a bit – some were quite low-carb (such as the Inuit and the Maasai), while some were quite high-carb.

Takeaways

What can we take away from this somewhat confusing mass of data?  Actually, a pretty clear, albeit nuanced, picture emerges:

• Meat is good.  No traditional societies eat no meat, even though some eat much less than others, and some eat quite a bit – and the archeological evidence indicates that most prehistoric humans ate if anything more meat than modern hunter-gatherers.  Most societies seem to eat as much meat as they can get – meat is the preferred food source, and carbohydrates the secondary source.  Even the Hadza get about 30%-35% of their calories from meat – which is about twice the 17% of calories from meat that the average American gets.  

• All these societies also eat at least some carbs – and some eat quite a bit.  So, clearly, carbs are not themselves intrinsically bad – although groups like the Inuit and the Maasai do show us that at least some of us can eat very few carbs and still be quite healthy.

• None of these groups eat any processed foods – the carbs they do eat come from whole food sources – fruits, veggies, nuts and seeds, tubers, and honey.  No processed sugar, corn syrup, or flour.  Even those who eat carbs tend to not rely as much on grains as honey, fruit, and starchy tubers.

• All of these groups are physically active and live otherwise healthy lifestyles.

So, it seems that people can eat either a very low-carb or a fairly high-carb diet and still be healthy, provided that they eat some animal products, live an active and healthy lifestyle, and include primarily unprocessed whole foods, even if that means a lot of plants.  Having said that, just because some humans can be healthy eating a lot of carbs doesn’t mean that everyone can, or that there might not be some real advantages to keeping your carbs low.

Caveats – Why Some of Us Can Eat Carbs (and Some Can’t)

• The Normal Distribution Curve.  As Dr. Ken Berry likes to point out, most things in nature naturally vary, and human physiology is no different.  We know that there is a bell curve (determined both by genes and lifestyle) that applies to human physical traits like height – the same is true of what our ideal diets are.  Different people, based on their genes, microbiome, activity level, and doubtless other variables we have not even discovered yet, seem to fall on different spots on the “carbohydrate bell curve”.  Until we develop more accurate, individualized testing of your genes and microbiome (assuming you would even want that), the only way to figure out what works for you is self-experimentation.

• Which carbs you eat matter a lot.  The Hadza may eat a lot of carbohydrates – but they are relying heavily on high-fiber, fairly low-glycemic-load carbohydrates like wild berries and tubers (and some honey, in all fairness).  They are eating few grains and no processed foods.  Weston A. Price observed that traditional cultures which ate a lot of carbohydrates often soaked, sprouted, and fermented them to make them more nutrient-dense and more digestible.  If you do choose to eat carbs, eat real whole foods, and prioritize fermented and other traditionally prepared foods.

• What you can get away with if you are healthy and lean may not translate to what you can get away with if you are already metabolically unwell.  In a very good interview between Dave Feldman and Gary Taubes, Gary Taubes tackled the question of why some people need to apparently severely limit carbohydrates from all sources in order to be healthy, even though many traditional cultures ate high-carb diets seemingly without problems.  The problem, he suggests, is carbohydrate intolerance.  It is processed carbohydrates (flour, sugar, corn syrup) in particular which cause carb intolerance, but once you have it, you may need to restrict all carbs, even those which would have been healthy for you before, in order to fix it.  If you only eat real whole foods from an early age, you may be able to eat fruit and sweet potato your whole life and never get fat, but once you have already been eating sugar, white flour, and corn syrup for decades and developed metabolic syndrome, your body’s ability to handle carbs has been compromised and you may need to cut out these otherwise healthy foods.

• Finally, some people are addicted to carbohydrates.  Maybe it is those dang processed carbs that caused the addiction – maybe if you never tasted a doughnut you could eat a sweet potato or a cup of blueberries once in a while, enjoy it, and think nothing of it.  But, now that you have spent years eating doughnuts and cake and pasta, maybe you can’t eat blueberries without thinking of blueberry doughnuts!  For some people, even if they can metabolically “get away” with eating a moderate amount of “healthy” carbs, they psychologically can’t.  Even the sweet taste of fruit will bring back old cravings.

Practical Takeaways – What to Do?

• If what you are doing is working, there is no need to change it.  Humans have been healthy eating both higher and lower carb diets.  If you can eat more carbs and stay healthy, that’s great!  If you need to keep your carbs lower, or just prefer being lower-carb, that is also a healthy and ancestrally-appropriate way to eat.

• If you do eat carbs, eat real whole foods and avoid grains and added sugar.  Eat lower-glycemic fruit (like berries) and starchy vegetables (think squash or maybe sweet potato).  

• Prioritize fermented vegetables and dairy like sauerkraut, kimchi, beet kvass, yogurt, and kefir.

• Prioritize meat and eggs.  Even higher-carb hunter-gatherers like the Hadza eat more meat than the average American. 

• There are distinct advantages to being in ketosis in terms of mental health, energy level, and mitochondrial health – so even if you eat more carbs, periodically fasting or having a low-carb phase every week or month may still give you added health benefits.

• If you are metabolically unwell, accept the fact that you may not be able to “get away” with what a person who has been healthy their whole life could “get away” with.  Low-carb diets are one of the most effective ways to reverse metabolic syndrome – even if it was the white flour and sugar which made you sick, you might need to cut out the potatoes, beets, and berries to reverse that damage. 

Conclusion

So, to come back to our original question, no, carbs are not bad per se.  Having said that, processed carbs (sugar, flour, and corn syrup) certainly are bad – and, unless you are currently very lean and healthy, carbs may very well be bad for you.  Like most things in life, the place of carbs in a healthy diet depends quite a bit on the person and the situation.  

Ancestral diets show that we can be healthy on either high or low carb diets – but the fact remains that, if you are already unwell, cutting carbs is one of the most effective ways to get better.  I’m not “anti-carb”, but I am “pro-low-carb”.  If you are seeking health-coaching, you very likely are not metabolically well, and very likely would benefit from reducing your carbohydrate consumption.

So, to get super practical:

• If you are lean, active, and metabolically healthy, stick with what you are doing if it is working.  Eat real whole foods and live a healthy ancestrally appropriate life, and don’t worry about counting macros.

• If what you are doing is not working, start out by cleaning up your diet and focusing only on real whole foods – eliminate all processed foods, all grains (even whole grains), all added sugar and corn syrup, and prioritize meat, eggs, and vegetables.  If you start losing weight and feeling better, great – no need to count macros.

• If you’re still not making progress, it’s time to start counting macros.  Start out cutting your carbs down to under 100 total grams a day; if that isn’t working (or it is working and you want to speed up your results), you can try going keto (under 50 grams a day) or even carnivore (zero grams a day) and see how it goes.  Take it slowly and see how you feel.

That’s pretty much it.  Self-experiment!  Carbs are not evil, but you don’t need them – and may do best without them.