Poor diet quality has been known as a leading cause of premature death in the United States, and much of the world, for 30 years or more.
To be clear, this is not about hunger or even food insecurity. The problem, quite simply, is that much of what passes for food in our culture — and almost everything marketed to our children — is willfully addictive junk.
We are both physicians, and when our careers began, the two forms of diabetes mellitus were known as “juvenile-onset” and “adult-onset” diabetes. What was then “adult-onset” diabetes is now called “Type 2,” largely because the former name is no longer apt. Obesity and Type 2 diabetes are now rampant among adults and children alike; they are pandemics in their own right. They have made the COVID pandemic vastly worse than it needed to be. And let’s make no mistake: They were fueled by companies’ pursuit of profit.
We may adopt a more hopeful view of diet quality by considering what happens when it is improved. A recent study in PLOS Medicine did exactly that. Using sophisticated modeling, the researchers estimated that shifting from a typical Western diet to a more optimal diet could add more than a decade to life expectancy. Previous studies have shown that improvements in diet, with other lifestyle practices such as physical activity, can slash rates of diabetes in those at high risk; treat high blood pressure as effectively as drugs; help shrink progression of atherosclerotic plaque in the coronary arteries; and over time, avert most cases of the chronic diseases that plague modern societies.
What is the formula for improving diet quality in the United States? The most important elements are less red meat and processed meat, and more nuts, legumes and whole grains. This is a fortuitous confluence, because nuts, beans and other legumes are outstanding protein sources, making “more beans, less beef” an easy and direct dietary swap. Of note, the benefits of this shift enhance planetary health as well as human health. Improving diet quality also includes reducing refined grains, added sugar and ultraprocessed foods while increasing whole vegetables, fruits and grains, and substituting fish for other meats.
Are these elements of dietary quality controversial? They are not. They are often derived directly from the benchmark Global Burden of Disease Study. They are informed by a massive aggregation of scientific evidence spanning decades, populations and diverse research methods. They represent a clear mandate in response to a clear and omnipresent danger.
In New York City, Eric Adams, who reversed his own Type 2 diabetes by improving his diet quality, is the rare politician accepting this mandate. As mayor, he is introducing policies in New York City to help shift diets — in schools, hospitals and one can only hope everywhere else — in the direction associated with more years in life, more life in years and less chronic disease.
Adams’ plans to make more whole, wholesome plant foods available are overdue and moderate. So of course, they are subject to resistance, derision and misrepresentation. What sensible thing in this world is not? But anyone whose family has been assaulted by heart disease, cancer, stroke, diabetes, dementia or even the dire toll of COVID should be saying to Adams: “Thank you, when can we do more of this?”
Arguments that incremental movement in the direction of more whole plant foods might lead to dietary deficiencies or harm are, in a word, absurd. For one thing, when reasonably well-practiced, even plant-exclusive diets readily provide protein ample in both quantity and quality, while contributing to better health outcomes overall. But Adams is not making anyone vegan; he is just helping New Yorkers shift diets in the direction of better quality. To cite dangers of any given nutrient deficiency in opposition to this is like arguing against rescuing someone from drowning today because they might, out of the water, be subject someday to dehydration.
The American food system — a system overseen by a federal agency mired in glaring conflicts of interest; a system where multicolored marshmallows are brazenly peddled as part of a “complete breakfast” for children prone to epidemic obesity and diabetes; a system in which animals are mass-produced as dubious food under conditions of shocking cruelty and at extreme environmental cost — is massive. The packaged food market in the United States alone is valued at more than $1 trillion, and the retail food market at more than $6 trillion. Those numbers represent colossal power.
So Mayor Adams’ policies are not merely right and reasonable and overdue; they are courageous as well. His efforts represent risk only to those who profit from the propagation of obesity and chronic disease. For all the rest of us, there is only reward. We should, accordingly, be cheering him on.
Katz is president of the Truth Health Initiative and past president of the American College of Lifestyle Medicine. Willett is a professor of epidemiology and nutrition at Harvard University.
