This study may be the single most important nutrition study ever conducted.
That’s a bold claim, right?
Yes! I do think this study deserves that title. (If not, it’s certainly vying for the top spot).
It’s a literature review that analyzed the scientific studies on basically every diet out there, along with everything the studies have shown us about their health effects.
It is the single most comprehensive and thorough modern scientific analysis of different dietary patterns, and it reached some very important conclusions that you need to be aware of.
The study is titled “Can We Say What Diet is Best for Health?” and it was conducted by David Katz, M.D.–the director of Yale’s Prevention Research Center, and one of my favorite health authors.
The study compared all the known data on the effects of everything from low-fat vegan diets to balanced diets to high fat, low-carb diets to Mediterranean diets to Paleo diets.
First, let me give you a brief bit of the abstract, and then I’ll tell you what they found.
“Diet is established among the most important influences on health in modern societies. Injudicious diet figures among the leading causes of premature death and chronic disease. Optimal eating is associated with increased life expectancy, dramatic reduction in lifetime risk of all chronic disease, and amelioration of gene expression. In this context, claims abound for the competitive merits of various diets relative to one another. … There have been no rigorous, long-term studies comparing contenders for best diet laurels using methodology that precludes bias and confounding, and for many reasons such studies are unlikely. In the absence of such direct comparisons, claims for the established superiority of any one specific diet over others are exaggerated… Efforts to improve public health through diet are forestalled not for want of knowledge about the optimal feeding of Homo sapiens but for distractions associated with exaggerated claims, and our failure to convert what we reliably know into what we routinely do. “
What Did The Study Find?
After analyzing hundreds of the most relevant nutrition studies ever conducted, synthesizing all of this information, and then analyzing the data, here is what they concluded:
“The aggregation of evidence in support of:
(a) diets comprising preferentially minimally processed foods direct from nature and food made up of such ingredients,
(b) diets comprising mostly plants, and
(c) diets in which animal foods are themselves the products, directly or ultimately, of pure plant foods—the composition of animal flesh and milk is as much influenced by diet as we are
—is noteworthy for its breadth, depth, diversity of methods, and consistency of findings.
The case that we should, indeed, eat true food, mostly plants, is all but incontrovertible.”
Why Aren’t We Doing This? And Why Are So Many People Still Confused About What They Should Be Eating?
“This message, however, is at present a relatively feeble signal lost in a chorus of noise. In pursuit of marketing advantage, notoriety, or some other bias, the defenders of competing diets tend inevitably to emphasize their mutual exclusivities. This pattern conforms well with prevailing media practices, and the result is perpetual confusion and doubt.
The clutter of competing claims likely obscures the established body of knowledge and forestalls progress, much like the proverbial trees and forest.”
In short, the ongoing battles of the macronutrients from the low-carb crowd vs. the vegan low-fat crowd, the sugar demonizers vs. the animal protein and animal fat demonizers, the “calories don’t count” low-carbers vs. the people who say it’s only calories that matter, and the people who place macronutrient ratios and calories ahead of eating nutritious whole foods.
To quote Katz again:
“No, saturated fat is not our nutritional nemesis, and never was. But neither is sugar, nor wheat, nor all grains. No one thing is the thing wrong with our diets, and no one food, nutrient, or ingredient will be our salvation either. Wholesome foods, mostly plants, in sensible combinations could be — assuming an 80% reduction in all chronic disease qualifies as salvation. … What stands in the way is not our admittedly imperfect knowledge of nutrition, because frankly, we know enough. What stands in the way is hyperbolic headlines, fixed agendas, reactionism, religious zeal, profiteering, finding only what we’re seeking, and failure to learn from the follies of history. In other words, what is far more perilous to our health than saturated fat or sugar is the prevailing standard of stupidity in the food for thought we swallow routinely. If there is a war to be waged against anything ingestible, I humbly suggest it be that.”
What You Should Take Home From This Study
In short: There is no real reason to be confused about what to eat. We already have a pretty damn clear answer to that question:
Eat a diet of real whole food. Mostly plants.
Once you’re doing that–and ONLY once you’re doing that–should you be concerned with how much carbs or how much fat you’re eating, or how many calories you’re eating.
But many people–including many, if not most diet gurus–have this BACKWARDS.
If you’re concerned over how much fat or carbs your diet has or how many calories you’re eating, and you’re NOT already adhering the foundational principle of REAL FOOD, MOSTLY PLANTS, then you’ve got things BACKWARDS.
If you think the key to good health and fat loss rests in the extent to which your diet is high or low in carbs, or sugars, or fats, or polyunsaturated fats, or saturated fats, or to what extent your food choices “fit your macros” then somewhere along the line, you got something backwards.
A diet of real, whole food and mostly plants (especially fruits and vegetables) comes FIRST.
Then–and only then–do you worry about your carbs and fat.
And quite frankly, if you are eating a diet of whole food that is mostly plant foods like fruits and vegetables, you probably don’t need to concern yourself with things like calories and macros.
Consider this advice from Katz:
“I think it’s time to stop talking about macronutrients, because people can cut carbs and eat badly, people can cut fat and eat badly, they can cut sugar and eat badly. Or you can cut carbs and eat well, or cut fat and eat well. …The focus on macronutrients has been a decades-long boondoggle. The answer is wholesome foods in sensible combinations. You do that, and the macronutrients will take care of themselves. Do calories matter? Of course they do. (But) the question “do calories count?” is a distraction. …The quantity of calories matters–it’s a law of physics. But the quality of calories–the quality of the foods we choose–is probably the single best way to control the quantity.”
Are you still confused about how to eat? You are only if you want to be.
The research has already answered that question pretty clearly.
Real food. Mostly plants.
That’s the foundation for everything. Only once you’re doing that do you need to start worrying about more advanced nutrition concepts.