The prevailing narrative about nutrition is that everything experts have long thought true has been proven wrong. That narrative is titillating and provocative, but it’s false. We’re all entitled to our own opinions, but not to our own facts.
Here’s some of what’s wrong with the idea that everything we know about nutrition is wrong:
The paleo diet is a panacea.
Eating and living like our Stone Age ancestors actually might be good for us, but not when the paleo banner is unfurled preferentially for bacon, sausage, and burgers. We can’t know how a true paleo diet would support the modern lifespan, and we never will: Everything our forebears ate in the Stone Age is extinct. They lived on wild game and wild plants, not industrially produced burgers and bacon. Most paleo marketing is classic, 21st-century hogwash.
The ketogenic diet offers unique benefits.
The ketogenic diet was once called “Atkins.” Since its inception, it has had ample opportunity to make everyone thin, vital, energetic, and ageless. Sure, there are testimonials, but that was equally true for the grapefruit diet, the cabbage soup diet, and every other variant on the theme of quick-fix-pixie-dust; they make excellent fads, but they’re not solutions. There is no evidence that ketosis can be maintained over time by healthy people; no evidence that health persists if it is; no evidence even of its safety. As for its disease-reversal (e.g., Type 2 diabetes) claims? Diets actually known to be sustainable and good for overall health do that, too, as will almost anything in the short term that causes weight loss. Finally, the world has to eat a whole lot less meat, not more, if we’re going to survive as a species. We may safely conclude that the “health effects” of a diet calamitous for the planet cannot be good.
Saturated fat was falsely vilified and has been exonerated.
Revisionist history is the cornerstone of the now popular idea that saturated fat was never really associated with heart disease. To be clear, the real problem here (and elsewhere) is not a given nutrient — it is imbalance. But because modern diets tend to deliver an excess of saturated fat, and because compounding that excess exacerbates imbalance, stated simplistically, saturated fat is generally “bad” for us. Its overconsumption is indeed linked to heart disease risk. Yes, excess sugar is also “bad.” All that demonstrates is that there’s more than one way to eat badly.
We failed to identify the health hazards of excess sugar.
Despite the thinly veiled bragging by a parade of self-declared maverick geniuses who contend they have at last revealed the ills of excess sugar the rest of us denied, reducing sugar intake has been a key public health message since 1980, when official Dietary Guidelines for Americans were introduced. The fact that we’ve never actually reduced our intake because lobbyists and marketers countered every recommendation and processors put sugar in nearly everything — well, that’s another matter altogether. But sugar has been correctly and officially identified as a bad actor for 40 years or more.
Carbohydrates are evil.
Cotton candy is a source of carbohydrates; so are cannellini beans. Marzipan is, and whole almonds. Twinkies and walnuts. Jelly beans and pinto beans. Lollipops and lentils. Maybe that’s enough said. Summary judgment of the largest swath of the food supply makes no sense at all. “Carbs” are not evil. Highly processed junk foods and the carbohydrates they deliver are not good for health. Whole fruits and vegetables, whole grains, nuts, beans, lentils, seeds — carbohydrate sources, all — most certainly are.
The more protein, the better.
We (those of us in America and other developed countries) get too much protein, not too little. Protein triggers an insulin release — yes, really — and excess calories from protein turn into fat, just like those of every other macronutrient. We can get all the protein we need from a balanced diet of plants. All plant foods provide all essential amino acids, in varying combinations.
Grains are bad, because of gluten (or something).
Whole grains are consistently associated with better overall health and weight. This is true both in observational studies of large populations and in intervention studies, including randomized trials. The idea that gluten is bad for all is confabulated nonsense, popularized by the kind of “science” routinely reported in People magazine, and parlayed into best-selling arguments against all grains. The unsubstantiated claims have also spawned a whole inventory of gluten-free junk foods. Avoid gluten if you’re sensitive; don’t assume sensitivity — and eat whole grains absent a specific, personal reason to avoid them.
Calories don’t count.
Arguments against the fundamental relevance of calories are generally a prelude to the sale of some alternative, magic-infused theory. Yes, of course, calories “from what” matters! That doesn’t change the fact that they all count.
Canola oil is bad; coconut oil is good.
Canola oil has one of the most salutary fatty acid profiles known, and is especially good in its organic, non-GMO, expeller-pressed incarnation. Coconut oil rode a wave of marketing hype but carried virtually no science to validate those claims. Unlike canola, even the best varieties of coconut oil lack reliable links to health benefits in the scientific literature.
All true knowledge derives from randomized control trials — unless an RCT produces results you don’t like.
Speaking as a scientist who has run randomized control trials for over 25 years, the idea that all knowledge depends on them is preposterous. (Find an apple; toss it in the air. What’s your level of confidence it will fall back down? That confidence is not based on an RCT.) Worse, RCTs can be put to ill use: They generate answers only to the questions we pose, and we can pose misguided questions, whether out of ignorance or willful manipulation. RCTs can themselves be manipulated to produce disastrous headlines and news cycles, undermining understanding and trust. A short-term RCT of cocaine versus placebo would show cocaine to be far better for weight loss. Imagine those headlines while asking yourself whether that “breaking news” really sounds like a good idea.
Meaningful homework on nutrition is more than a web search to see if somebody, somewhere agrees with you: Online, Elvis lives, the earth is flat, and vaccines cause autism. To figure out what’s real, we must look for all relevant evidence on the topic instead of selectively screening for an opinion; we must judge everything by the same criteria, whether we’re inclined to like it or dislike it.
Yes, the food pyramid and dietary guidelines have always been imperfect — but they are the product of lobbying and politics, never a pure representation of what experts thought or think. Experts have long lamented the divide between what the science says and what politics does with the science — and we still do.
Yes, our culture popularized low-fat junk food, just as it proceeded to do with low-carb junk food, gluten-free junk food, non-GMO junk food. But that never represented expert guidance, either, and has always been a for-profit exploitation of messages that made sense in context. Reducing dietary fat makes sense when it means less pepperoni, more pinto beans; but not when it means all the Snackwell’s you can eat. Avoiding gluten makes sense when sensitive to it, but not otherwise — and certainly not when it means jettisoning whole grains for no valid reason.
In other words, you are being duped on a daily basis into tossing out the baby with the bathwater. This history of willfully garbling expert consensus about nutrition has been further garbled into a renunciation not of garbling, but of expertise.
As the saying goes, there’s a sucker born every minute. These days, you are apt to find them queued up at the never-ending media circus, feeding on misinformation, swallowing something they should not. My advice to you? Don’t get in that line!