The way we eat desperately needs to change. Experts estimate diet is a bigger contributor globally to early death than smoking. In America, nearly half the adult population has Type 2 diabetes or pre-diabetes.
If you have been following recent headlines, it may seem like there’s a single culprit: ultraprocessed foods. These industrially produced foods with weird, hard-to-pronounce ingredients that you can’t find in your kitchen have been linked to Type 2 diabetes, depression, heart attacks and Alzheimer’s disease. They are “driving the obesity epidemic,” according to Robert F. Kennedy Jr., president-elect Donald Trump’s pick for health and human services secretary.
It may come as a surprise, then, that an expert committee of scientists advising on the federal government’s dietary guidelines (the set of recommendations, released every five years, that shapes nutrition education and school lunches, among other things) recently declined to take a strong position against ultraprocessed foods. The experts felt that there wasn’t enough reliable science to draw accurate conclusions.
They were right about that. The problem is that the category of ultraprocessed foods, which makes up about 60 percent of the American diet by some estimates, is so broad that it borders on useless. It lumps store-bought whole-grain bread and hummus in with cookies, potato chips and soda. While many ultraprocessed foods are associated with poor health, others, like breakfast cereals and yogurt, aren’t.
Processing can also create products suitable for people with food intolerances or ones that have a lower environmental footprint. (Full disclosure: I have consulted for food companies that I feel make beneficial products, including Beyond Meat, which makes ultraprocessed meat alternatives that I believe are better for the planet.)
The most famous study on ultraprocessed foods was a randomized trial conducted by the National Institutes of Health, which compared an unprocessed diet, high in fresh fruits and vegetables, to a diet made up of ultraprocessed foods, but matched the amount of salt, sugar and fiber in the diets. The findings: People consumed about 500 calories more per day and gained more weight on the ultraprocessed diet. If it wasn’t the salt, sugar or fiber, what caused people to eat more?
It probably came down to energy density — how many calories are packed into each gram of food. In the N.I.H. study, the food in the ultraprocessed diet (not counting beverages) was overall almost twice as energy-dense as that in the unprocessed one. Studies have shown that we tend to overeat foods high in energy density. To understand why, think about how much fuller you might feel after eating three cups of broccoli (a low-energy-density food) compared with eating half a Hershey’s Bar (a high-energy-density food), even though in both cases you’d be consuming 100 calories.
Energy-dense foods tend to have less water and fiber and more fat compared with less energy-dense foods, like fruits and vegetables. Ultraprocessed foods are often very energy-dense because food companies have incentives to add fat or sugar to make foods tastier, and to remove water to make foods more shelf stable and cheaper to transport.
Ultraprocessed foods also tend to come in forms that we consume more quickly. (Think about how little time it takes to gulp down a premade smoothie compared with eating a bowl of fruit.) And specific combinations of ingredients — carbohydrates combined with salt or sugar and fat — seem to lead us to overeat.
But if the problem is calorie-dense foods that contain lots of salt, sugar and fat, then homemade fries or cookies probably aren’t all that much healthier than the ultraprocessed, store-bought versions.
What about all the additives in ultraprocessed food, like xanthan gum, lecithin and tartrazine? To date the research that has been conducted is reassuring about many of these, but we do need more studies, particularly on gut health and in cases where observational studies suggest some risk. In my own diet, I focus my choices on where the evidence for health is strong and unequivocal: eating lots of fruits and vegetables and lean protein. If the evidence on additives changes, I’ll change my diet.
But if ultraprocessed foods tend to be less healthy anyway, why not just recommend avoiding them completely?
Because for the vast majority of the population, this is unrealistic. Consider a taxi driver trying to find something to eat at 2 a.m. or a single parent working three jobs. Telling that person to marinate meat, chop vegetables and make brown rice from scratch is not likely to get much traction. It may be better to say, “Hey, here’s a pretty healthy frozen meal and some veggies you can pop in the microwave and eat alongside a piece of fruit.”
Of course, we should aim to consume a diet rich in unprocessed foods, such as oily fish, nuts, fruit and vegetables, as the expert committee advised in its report. And our modern food environment needs to change. It’s not surprising that the population is so unhealthy when it is far easier and cheaper to get cakes, cookies, chips and other junk food than it is to get a healthy, balanced meal.
But focusing on processing as a heuristic for the healthiness of foods risks throwing the baby out with the bath water. Take supermarket bread. Some well-to-do parents are baking their own bread to avoid the evils of industrial processing. But studies have not found a difference in health impact between industrially processed and homemade bread. And butter — churned from a single natural ingredient (milk) — is high in unhealthy saturated fat.
The focus on ultraprocessed foods has been a distraction from what we already know about nutrition, and we should have acted on it decades ago. We consume too much fast food, too many sugary beverages, too many cakes, doughnuts and chips. And we consume too few legumes, fruits and vegetables.
We need better food and nutrition policies that make it easier for people to purchase and consume a healthier diet. Pricing is one of the most effective ways to influence food purchasing and consumption habits. Soda taxes are a great example; these have led to reductions in sugar intake for children and adults, and emerging evidence suggests that children living in cities that tax soda are less likely to become obese. Such taxes could be extended to other high-sugar, high-calorie foods, like cookies and doughnuts, which have no nutritional benefits, and which we tend to overeat. Perhaps the revenue from this so-called doughnut tax could be used to subsidize the cost of fresh fruits and vegetables. Studies show that people support higher taxes on unhealthy foods if they are used to make healthy options cheaper.
Mr. Kennedy and critics of ultraprocessed foods are right that our food landscape is very broken, and ambitious efforts that take on vested interests are needed to change it. The biggest dietary ills have been known for half a century; we need the new administration to finally act on them.
Nicola Guess is a dietitian and researcher at the University of Oxford. She also runs a private clinic and has worked as a consultant for food companies, including Beyond Meat. This article originally appeared in The New York Times.
