We’ve all been there.
A giddy chat with your neighbor who dropped fifteen pounds by nixing starches and sugar.
A lithe, shadow-of-his-former-self coworker who’s raving about the plant-based diet he’s been on since June.
An email from your olive-oil-evangelizing sister who swears she feels ten years younger after switching to a Mediterranean diet.
Internet buzz around the fat-busting potential of whole grains—right next to more buzz about wheat’s nefarious role in obesity.
Dozens of diet books claiming they’re the last one you’ll ever need—and each one preaching something wildly, irreconcilably different from the next.
Is it any wonder so many people give up learning about this diet stuff almost as soon as they begin?
My own story was the same.
Cutting Through Confusion: There’s No One-Size-Fits-All Diet—And Here’s Proof
After spending a decade sliding from vegetarianism to veganism to raw veganism, I witnessed a fair bit of “miraculous” success within the plant-based community—though the journey left my own body tooth-decayed, deficient, and voluntarily swaddled in ski jackets in weather below 70 degrees. When I finally forayed beyond the plant kingdom to save my own health (and regain some semblance of body heat), I was greeted with more of the same: glowing successes on paleo mixed with folks unable to shed a pound; starch-based diets boosting health for some while stranding others on a blood-sugar roller coaster; experts wagging a finger at fat, grains, carbs, sugar, fructose, dairy, animal protein, and any other villain du jour in attempt to explain our modern health woes.
None of it made sense. How could people embark on such wildly different diets and achieve similar success (or similar failure, for that matter)? How could one person feel better cutting out meat and another feel fabulous eating it with every meal? Why couldn’t the experts even agree on what we should be putting in our mouths?
Answering those questions has fueled my own research adventures over the years, both to satisfy my curiosity and to save my sanity. Maybe you’re in the same boat. And if that’s the case, I’d like to help navigate this crazy ship to shore.
Believe it or not, there’s a reason confusion reigns supreme. And it’s not because we still need to figure out the precise number of daily blueberries and spinach leaves it’d take to reach immortality. Rather, it’s because the Dietary Holy Grail—that creature so many authors, health gurus, and nutritional self-experimenters are vying to capture, the single diet that will give all of us rockin’ bodies and a centenarian lifespan—is a mythical beast. A unicorn, of sorts, prancing through our imaginations but not through reality.
As great as it would be to find a “human species diet” perfect for everyone on the planet, it’s a futile quest. And here’s why.
A Legacy of Diversity
If anything defines our two-million-year-long diet history, it’s adaptability. The power to make food out of whatever our environment spits out at us (or rather, whatever we manage to wrestle from its grasp). We’ve infiltrated every corner of the globe, trekked through the most inhospitable of climes, devised hacks for turning any life form into something edible, and—for the most part—lived to tell about it. That’s pretty awesome. Go us!
But more than just surviving, we’ve also managed to thrive on a wide spectrum of diets. And one of the most fascinating portals into that reality comes from the work of Weston Price, an early-1900s dentist who scoured the globe in search of isolated populations still eating their traditional cuisines, untouched by Western foods and ways.
Though his focus was often tooth-centric—seeking out communities free from the dental decay ravaging Americans, and trying to find out what made the healthiest-mouthed folks immune—his findings reached far beyond the realm of dentistry. In an expedition that’d be all but impossible to repeat today, Price encountered humans at their absolute prime: free from chronic disease, straight-toothed without braces, cavity-free without floss and Crest, strong, sturdy, happy, healthy.
And it wasn’t just genetic luck of the draw, either. Price also observed that as soon as those isolated populations switched over to “nutrition of commerce”—refined flours, sugars, vegetable oils, jams, canned goods—their health tanked just like the rest of the Western world. Through generations of trial and error, each community had found a combination of foods to build the healthiest bodies possible.
Intrigued? Here’s a snapshot of what some of the healthiest communities ate as mainstays, summarized from Price’s book Nutrition and Physical Degeneration.
The Swiss of the Loetschental Valley:
- Fresh, hand-milled rye bread
- Raw cheese, butter, and milk from cows eating fast-growing alpine grass (which supercharged the dairy with vitamins)
- Local vegetables, both fresh and preserved
The Native Americans of the Rocky Mountains:
- The organs and bones of wild game, particularly moose and caribou (muscle meat was typically fed to the dogs rather than used as human food)
- Bark, tree buds, and other vegetation, particularly in the summertime
The Gaelics in the Outer and Inner Hebrides:
- Oats at every meal, mostly in the form of oat porridge and oatcakes
- Local seafood including fish, lobsters, crabs, oysters, and clams; cod liver was particularly revered
- Fresh vegetables in the summer; stored vegetables in the winter
The tribes in Eastern and Central Africa:
- Starchy foods like sweet potatoes, beans, corn, and millet
- Fish, shellfish, and water plants
- Wild game, or domesticated goats and cattle used for meat and dairy
- Insects like ants and locusts—used in pies, puddings, or dried and ground into flour
The Eskimos of Alaska:
- Sea animals—particularly the organ meats, oils, and skin
- Fish and fish eggs
- Caribou and other land mammals
- Vegetation collected in the summer and saved for the winter—including cranberries, kelp, water grasses, bulbs, ground nuts, and flower blossoms preserved in seal oil
So there you have it.
No one counted carbs or fat. No macronutrient ratio was a universal sweet spot. The rye-eating Swiss hardly shied away from gluten; nor did the Aborigines get the memo that they were tragically deficient in Healthy Whole Grains. The Gaelics’ oats-with-every-meal habit flew in the face of paleo diet wisdom, while the Eskimo’s meaty menu should have doomed them to disease, according to plant-based diet proponents. Cholesterol-rich organ meats and shellfish were prized rather than feared. Successful diets ranged from high-starch to starch-devoid; from meat-based to meat-scarce; from high-grain to no-grain.
In other words, those traditional diets ran the gamut. Yet in every instance, they produced remarkably, enviously healthy groups of humans. Go figure!
So what can we take away from that? Along with bolstering the idea that many different diets can support health, those traditional cuisines all had a few things in common—pockets of overlap we’d best pay attention to. In each case, those health-promoting traditional diets:
- Contained a rich source of fat-soluble vitamins (particularly vitamins K2, A, and D)—whether from organ meats, high quality dairy, fish eggs, other seafood, or insects.
- Were free from vegetable oils, white sugar, white flour, and canned foods.
- Placed muscle meats pretty low on the totem pole—valuing instead an animal’s organs, skin, bones, and cartilage.
- Contained a mix of both plant and animal foods, with no diet being entirely carnivorous or entirely vegan.
Of course, while Price’s findings show humans can thrive on an impressive range of diets, we’re still left with a glaring question. How come folks today respond in wildly different ways to the same foods and diets? Is it all in our heads?
You’re a Special Snowflake
It turns out your parents were right after all: you’re special. Not in a sticking-crayons-up-your-nose way, but in an “individual variation” way. Although we humans all share some obvious features—two lungs, a digestive tract, an innate desire to argue on the internet—we actually have some important differences once we zoom in a bit further. And those differences become critical when we look at how our diet interacts with our genes.
Did you know you start digesting your food before you even swallow it? True story. Your saliva is teeming with proteins that kick off the digestive process—including amylase, an enzyme that breaks down starch into sugar. It’s coded by a gene called AMY1.
Here’s where it gets interesting. The more AMY1 copies you carry, the more amylase you pump out in your saliva. In fact, depending on your genes, the amylase in your mouth can range from barely detectable to a whopping 50 percent of your saliva’s total protein.
And for each person’s ability to handle starchy foods, that spells mega variation. Studies show that when low-amylase producers consume starch, their blood sugar surges far higher—and stays hiked for much longer—than high-amylase producers eating the exact same thing. In other words, the more AMY1 copies you’ve inherited (and the more of this enzyme you produce as a result), the better your starch-metabolizing capabilities will be.
And where you land on the amylase spectrum isn’t just luck of the draw. Folks from traditionally starch-centric populations, like the Japanese or the Hazda of Tanzania, tend to carry more copies of AMY1 than folks from starch-scant populations, like Siberian pastoralists or hunter-gatherers from the Congo rainforest. The reason? Selective pressure. Producing more amylase was a boon for populations relying on starchy foods—so over time, survival-of-the-fittest style, more AMY1 copies came to dominate their gene pools. In populations where starch was a dietary rarity, AMY1 copies tended to stay low. The diet of your ancestors, then, plays a big role in what’s best for you today.
For the modern health enthusiast, this is big news. While high amylase producers might fare well on a starch-based cuisine, low amylase producers eating the same diet would probably catapult headfirst into a heap of blood sugar swings and swollen fat cells. Keep that in mind next time you see your slim friend downing a bag of Ritz crackers while you seem to gain weight just sniffing the box.
APOE is a fascinating little gene that codes apolipoprotein E (or ApoE for short), a protein involved in lipid metabolism and cholesterol transport. Depending on what you inherited from your parents, you’ll carry a combination of any two ApoE variants: ApoE2, ApoE3, or ApoE4.
Recently, that last one—ApoE4—has been grabbing the research spotlight due to some of its quirks. And not in a cute, Zooey Deschanel sort of way. Along with having a much higher risk of Alzheimer’s disease, ApoE4 carriers tend to react to high-saturated-fat diets with a rise (sometimes scary-high) in LDL cholesterol. Alas, we still need a great deal more research to fully understand the interaction between diet and ApoE status. But in the meantime, ApoE4 is a big clue why some people see their LDL spike after adopting a paleo or low-carbohydrate diet, even when their friends might boast a lovely lipid profile eating steak galore.
Vitamin A Conversion
Ever wonder why some people seem to rapidly self-destruct on vegetarian and vegan diets, while others ride off into the sunset with nary a complaint? Part of the reason involves vitamin A conversion—or lack thereof, as the case may be.
Contrary to popular belief, plant foods like carrots don’t contain any vitamin A. They contain precursors, particularly beta-carotene, that your body has to transform into a usable form of the vitamin. Animal foods are the only sources of vitamin A in its “preformed” state.
The problem? While some folks can convert enough vitamin A from plant foods to meet their needs, others are genetically doomed to fail at the job. Two common mutations on the BCM01 gene—which helps govern the beta-carotene-to-vitamin-A conversion process—make it nearly impossible to get enough vitamin A from the plant kingdom alone. And if those mutation-carrying folks decide to go veggie, slashing vitamin A intake and relying on beta-carotene instead, the results aren’t pretty. Infertility, plummeting immune function, skin problems, vision problems, hair loss, bone loss, brittle nails, and increased susceptibility to infection can all follow on the heels of vitamin A deficiency. (And not surprisingly, those are all common complaints among those who’ve “failed” on vegan or vegetarian diets.)
The next time you see someone pushing the one-size-fits-all diet idea, feel free to admire their chutzpah—while swiftly running for the hills. As seductive as simple solutions and blanket prescriptions can be, that Dietary Holy Grail quest will always be fruitless. Don’t fall under its spell.
Though it might seem frustrating, our diversity is actually pretty empowering. Honoring each other’s differences can help dissolve the tribalism so prevalent in the health world—that tendency to feel threatened when someone does well on a diet other than our own, to peg those outside of our favored community as enemies instead of looking for common ground. By understanding how we each differ, we can start working hand-in-hand rather than head-to-head. Success isn’t a finite resource, especially where diet is concerned.
Author Denise Minger has just written the book “Death By Food Pyramid”. I would highly recommend this book if anything in this article struck a chord with you. Leave your questions, comments and feedback below, and be sure to click here to grab the book now.