This article is part of a series on the Word of Wisdom. To view all the articles in this series, see Discovering the Word of Wisdom.

Last week in Gut Reactions to Low Carb Diets, I explored the negative impact low carb diets have on our microbiome. If you’ve missed any of the articles I’ve done so far on the human microbiome, here are the previous titles:

In this series on the microbiome, I’ve been emphasizing the importance of a high fiber whole food, plant-based diet. In popular lingo, it is a “high-carb” diet. It contains lots of foods high in complex carbohydrates, like potatoes, beans, peas, lentils, corn, whole wheat, whole grain pasta, brown rice, and oats. In a world where some people have a hard time digesting carbs and “low-carb” diets are very popular, “high-carb” can sound frightening. I hope to give readers who worry about consuming complex carbohydrates some reasons to not give up on these foods.[1]

The central reason to not give up on carbohydrates is that fiber-rich whole plant foods are the very foods ideally packaged for human health.[2] Throughout history, all large, healthy populations have gotten the majority of their calories from high-carb plant foods.[3] These foods not only prevent chronic disease, they have the power to reverse it.[4] Diets high in complex carbohydrates (whole plant foods) are consistently associated with health and wellbeing, while diets high in fat and protein (animal foods and processed foods) are associated with long-term weight gain, a litany of health problems, and degenerate disease.[5] If we want to enjoy radiant health, we can’t give up on carbs!

My rationale for why humans do best on a high-carb diet goes beyond history and science to include the dietary counsel given by revelation to Joseph Smith. In the Word of Wisdom, the Lord instructs us to minimize the use of meat and to center our diet on wholesome plants and especially grains, foods that are all high in carbohydrates (see D&C 89:10–17). The world is telling us just the opposite: reduce complex carbohydrates (starchy plant foods) and increase fat and protein (animal foods).

The science of nutrition did not exist in Joseph Smith’s day, so the Prophet had no idea how controversial the Lord’s words would appear in our day. In a day when the world is rejecting so many of the Church’s fundamental teachings, perhaps we should not be surprised that the world is also rejecting the dietary counsel in the Word of Wisdom. But we Latter-days Saints have an advantage the world does not have.

But Aren’t Carbohydrates Hard to Digest?

If the Lord recommends a diet high in carbohydrates, why do so many people have a hard time digesting carbohydrates? Why are low-carb diets so popular? Why do some people report feeling better when they eliminate grains and other carbohydrates from their diets?

Is it possible that at least some people should go low-carb? Isn’t the fact that some people feel better when reducing carbohydrates proof enough that a low-carbohydrate diet is better for them?

I invite readers to consider an alternative explanation. I’d like to introduce this by way of an analogy that admittedly will sound far-fetched at first, but I believe it is not as far fetched as it initially appears.

An Imaginary World of Toothless Humans

Let’s imagine the human race evolved (or rather devolved) to a state where food was only consumed in liquid form. Let’s also imagine that because humans stopped using their teeth to chew food, that their bodies no longer grew teeth, and so everyone is now toothless. Generations have gone by and this state of affairs is accepted by everyone as natural and proper. Perhaps a few might miss the toothy look of former days, but most people do not miss their teeth since they are not needed for consuming food. Many even note the advantages of not having to do all the work their “primitive” ancestors had to do: brushing, flossing, and suffering through painful visits to the dentist’s office. I know this sounds ridiculous, but hang in there!

What might happen if some citizens of this toothless world one day decided to try eating a whole carrot or an apple or corn on the cob? Ouch! That would feel pretty uncomfortable. Would it not be logical under such conditions for people to assume that “the human mouth is not designed to eat whole foods”?

While this situation sounds absurd, it actually presents a close parallel to what is currently happening in our society today. The fact is: our diets have dramatically changed over the course of several generations.[6] The low fiber, high animal food diet we are now consuming is doing something just as lethal to our bodies as damaging our teeth: it is totally changing the nature of our microbiome, the complex community of microbes that inhabit our bodies and that play a vital role in key biological functions.[7]

One of the most important functions these microbes perform is digesting our food, and in particular, digesting the carbohydrates in our diet.[8] In fact, the indigestible dietary fiber in foods with complex carbohydrates are the very foods these bacteria depend on for their survival. Without these foods, they can’t provide the important services we depend on for our survival.[9] If we don’t have teeth, we have a hard time chewing food, but if we don’t have the right kinds of bacteria in our gut, we can’t properly process carbohydrates.[10]

Let me state that again: if we don’t have the proper bacteria in our gut, we can’t properly process carbohydrates.

Today we hear of many in our society who experience problems digesting carbohydrates. They blame the carbohydrates and claim that our bodies are not designed to eat so many carbs. In the imaginary toothless world, people would also blame the foods and claim that their bodies are not designed to eat solid foods. Perhaps, some in that toothless society would suggest the foods had “changed,” they are “harder” than they used to be, or why would it hurt the mouth to chew them? From our vantage point, the problem is obvious; it is not the foods that have changed so much as their own bodies. They changed the foods (turned them into a liquid) and the foods then changed their bodies (they stopped producing teeth), and the new toothless bodies can’t handle the old foods.

Our Foods Have Changed How Our Bodies Function

In a similar way, we’ve been changing our foods for the last 100+ years by dramatically reducing the fiber. Since what we eat determines the health of our microbiota, these changes to our food are literally changing the way our microbiomes function in our bodies.[11] We should not be surprised that our “new bodies” are now not as capable of handling the high carbohydrate foods our ancestors have consumed since the beginning of history.

The impact of less fiber in our bodies has been as dramatic as if we lost all our teeth: we just can’t see it as clearly. A toothless person will find that eating real foods is hard without teeth because chewing real food is what teeth are designed to do. Likewise, since our microbiomes have changed to accommodate our low carbohydrate, high protein diets, we will find that with a compromised microbiome, digesting carbohydrates may be difficult because digesting carbohydrates is what a healthy microbiome does best.

Humans are Natural Carbohydrate Consumers

Our human bodies—and the microbes that live in us—are both designed to be fueled by carbohydrates.[12] All plant foods naturally contain carbohydrates, protein, and fat, but the dominant macronutrient in plant foods is carbohydrates. Roughly 80% of the calories from most plant foods come from carbohydrates. (Animal foods, on the other hand, contain only fat and protein but no carbohydrates, except for the simple sugars in dairy.) Carbohydrates include sugars, starches, and fiber which provide two important nutrients:

  1. Glucose (from the sugars and starches) is designed to fuel our bodies.
  2. Dietary fiber (the part of plants our bodies cannot digest) is designed to fuel the microbes that live in our bodies.

Just as all of human history and modern science supports the claim that teeth are natural to the human body and that chewing food is proper, so does history and science support the claim that humans are designed to consume a diet high in fibrous plant foods, which means a diet high in carbohydrates.[13] In fact, our modern day is the only period of human history when plant foods have not been the dominant part of the human diet for the vast majority of the human population.[14] Both the scientific and clinical evidence reveals that the result of moving away from this natural human diet is obesity and chronic disease.[15] If we are skeptical of this history or this science, we Latter-day Saints are fortunate to have the Lord’s revelation to Joseph Smith on this very topic (see D&C 89).

I find it frightening that an increasing number of people in our society are finding it hard to digest foods high in carbohydrates. I’d be equally alarmed if people were finding they could not chew their food or breathe the air or swallow water. Think about it: oxygen, water, and carbohydrates are all fundamental to our wellbeing. We can’t pollute the water or air without compromising our health. Reducing consumption of healthy (whole, complex) carbohydrates has the same negative impact. I doubt there is even one reader whose life is not affected by the modern diseases that are a direct consequence of reducing healthy carbohydrates and increasing fat and protein in our diets: heart disease, diabetes, strokes, cancer, kidney disease, osteoporosis, allergies, food intolerances, gastrointestinal disorders, autoimmune disease and so forth.

If we can’t digest carbohydrates, something has gone fundamentally wrong with our bodies. The answer is not to permanently reduce or eliminate carbohydrates from our diet. That will only mask the problem, not resolve it. The answer is to fix what is wrong with our bodies, and that will require restoring the body’s ability to thrive on a diet high in complex carbohydrates.

Fortunately, fixing our microbiome is a whole lot easier than getting teeth to grow! By adopting a few lifestyle changes, including switching to high-fiber whole food, plant-based diet, it is possible to restore health to our bodies and to our microbiome. (For suggestions on useful changes we can make, see: 5 Ways to Care for Your Microbiome.)

For people with a microbiome that is severely compromised, there may be some challenges to increasing fiber in the diet. Because our gut bacteria are so central to digestion, if our gut bacteria have been damaged, we may experience some pain as we increase our fiber intake. This pain is NOT a sign that these foods are bad for us. It is a sign of a relatively unhealthy gut flora. But we should not back off, for the more fiber we consume (increasing the amount gradually, if needed), the more we are nurturing the gut flora needed to consume the foods the Lord created for our “constitution, nature, and use” (D&C 89:10). If your current diet is low in fiber, here are some tips for “Adjusting to Increased Fiber.”

(Note that if you are on a carbohydrate-restricted diet for a health condition or have severe gastrointestinal disorders, you may need the assistance of a trained health professional as you re-introduce certain carbohydrates into your diet.[16])

Replace Carb-phobia With Carb-philia

Carb-phobia, a fear of carbohydrates, is a powerful prejudice in our day. No doubt there are many carbs we can do without: processed carbs, junk food carbs, and carbs full of fat and sugar are all carbs we’d do well to avoid. But attacking all carbs is throwing the baby out with the bathwater. Our bodies are designed to run on healthy carbohydrates, and our healthy gut bacteria can’t survive without them. The problem today is not too many carbs; it is too few.

So where do we find the “healthy carbs?” This is the easy part: whole fruits, whole vegetables, whole grains, and whole legumes. These are the “wholesome” plants the Lord ordained for our “constitution, nature, and use” (D&C 89:10). These wholesome foods not only contain healthy carbohydrates, they contain all the protein and fat that our bodies require.

What then should be the role of animal foods in our diet? Since wholesome plants provide all the nutrients we need from food, there is no need for animal foods where plants are plentiful. Perhaps that is why the Lord is “pleased” if we don’t use the flesh of animals except in times of need (see D&C 89:13).

History and science both confirm the importance of consuming a high carbohydrate diet, but to me the endorsement of the Lord for such a diet makes all the difference. He not only endorses the counsel in Section 89, He calls it a “principle with promise” (D&C 89:2–3). Could we do any better than to have the Lord’s promise?

For Help Getting Started

For help getting started on a healthy Word of Wisdom diet, see: “Getting Started.”

Jane Birch is the author of Discovering the Word of Wisdom: Surprising Insights from a Whole Food, Plant-based Perspective and many articles on the Word of Wisdom. She can be contacted on her website, Discovering the Word of Wisdom. Watch the video “Discovering the Word of Wisdom: A Short Film.”


[1] I’ve written extensively about the importance of complex carbohydrates, especially grains. See: “Gluten, Wheat, Grain (and other food sensitivities).”

[2] Two excellent resources on this topic are: (1) Joel Fuhrman, Eat to Live: The Amazing Nutrient-Rich Program for Fast and Sustained Weight Loss (New York: Little, Brown and Company, 2003) and (2) T. Colin Campbell, Whole: Rethinking the Science of Nutrition (New York: BenBella Books, 2013).

[3] I appreciate the simple, straightforward approach to this topic in this excellent book: John A. McDougall, The Starch Solution: Eat the Foods You Love, Regain Your Health, and Lose the Weight for Good! (New York: Rodale, 2012).

[4] Caldwell B. Esselstyn, Jr., Prevent and Reverse Heart Disease: The Revolutionary, Scientifically Proven, Nutrition-Based Cure (New York: Avery, 2007).

[5] The books listed above also cover this topic very well, but my favorite book on this topic is: T. Colin Campbell and Thomas M. Campbell II, The China Study: The Most Comprehensive Study of Nutrition Ever Conducted and the Startling Implications for Diet, Weight Loss, and Long-term Health (Dallas: Benbella, 2006).

[6] Many authors have written on this topic. Historian Harvey Levenstein’s work is filled with interesting details. See Revolution at the Table: The Transformation of the American Diet (Berkeley: University of California Press, 2003) and Paradox of Plenty: A Social History of Eating in Modern America (Berkeley: University of California Press, 2003).

[7] Moises Velasquez-Manoff, “How the Western Diet Has Derailed Our Evolution,” Nautilus (November 12, 2015).

[8] Justin Sonnenburg and Erica Sonnenburg, The Good Gut: Taking Control of Your Weight, Your Mood, and Your Long-term Health (New York: Penguin, 2015).

[9] Ibid.

[10] Yu-Jie Zhang, et al. “Impacts of gut bacteria on human health and diseases,” International Journal of Molecular Sciences,16(4) (April 2015): 7493–519.

[11] Kirsty Brown, et al., “Diet-Induced Dysbiosis of the Intestinal Microbiota and the Effects on Immunity and Disease,” Nutrients 4(8) (August 2012): 1095–1119.

[12] Again, there is much written on this topic, including many of the resources in these notes, but this well-referenced book takes a particularly in-depth look: Don Matesz, Powered by Plants: Natural Selection & Human Nutrition (Integrity Press, 2013).

[13] Ibid.

[14] McDougall, The Starch Solution.

[15] Campbell and Campbell, The China Study.

[16] On interesting example of a program that carefully restricts than re-introduces carbohydrates is the Low FODMAP Diet from Monash University in Melbourne, Australia. The researchers behind this diet are careful to note that carbohydrate restriction is a short-term measure to restoring health—see Jane Varney, “Low FODMAP diet – not a ‘lifetime’ diet,” (Monash University, April 27, 2015).