A Top Nutrition Scientist Explains What We Should Actually Eat For Better Health

Today, it’s clear that several foundational principles outline the key features of a healthful diet. Within this framework, what to eat can be considered in three broad categories. At the top are protective foods, items with distinctive qualities that nourish our tissues and our microbiome. The list includes fruits, nuts, seeds, vegetables, beans, whole grains, plant oils, fish, and yogurt. These are foods to embrace, to fill our plates with life-sustaining flavor.

The next tier includes foods with more intermediate health implications: minimally processed animal products such as cheese, poultry, milk, eggs, butter, and unprocessed red meat. These contain important nutrients yet not the same wealth of beneficial bioactives as those in the highest tier. Within this category, some options have greater value (like cheese, a fermented choice) while others fall a bit lower on the scale (like unprocessed red meats, having pro-inflammatory and carcinogenic potential that must be balanced against its other benefits).

Prioritizing “natural” ingredients is not a bad start, yet a soft drink or refined breakfast cereal with all-natural ingredients can still promote obesity. Choosing “organic” will reduce exposure to synthetic pesticides, but it doesn’t eliminate risks from organic pesticides—and organic junk food is still junk food.

In 2018, I spoke in Washington, DC, at the Partnership for a Healthier America conference, an initiative that grew out of Michelle Obama’s Let’s Move campaign to convene policymakers and the private sector. At the event, a rising Los Angeles start-up, took the stage to unveil its first-ever television ad. As the thirty-second spot played—flashing beautifully fashioned images, words, and music—my eyebrows rose at one of the featured products: organic gummy bears. Is that really the great food crisis we need to solve? That America doesn’t have organic gummy bears? No, simple labels or rules are not foolproof and may even steer people in the wrong direction. A nuanced, fact-based understanding of nutrition—including some appreciation of the underlying science and biology—is important to build capacity for informed and thoughtful choices.

Three distinctive qualities make these foods exceptionally effective in promoting human health.

First, they are treasure troves of bioactives—polyphenols, flavones, flavonoids, isoflavones, carotenoids, and others—that offer antioxidant, anti-inflammatory, and pro-immune benefits critical not only to the success of a new seedling but also to that of our own bodies and microbiota as we grow, adapt, and age. As these nutrients evolved to support the plant, they also did so to benefit the creatures that consume them—providing an evolutionary advantage to maximize the animals’ likelihood of dispersing the seeds by ranging widely and reproducing successfully.

Second, these foods are abundant in fermentable fibers, which support the gut microbiome and are metabolized into beneficial signaling molecules that maintain health throughout the body.

In this group, nuts and seeds are some of the most remarkable foods, gram for gram, than virtually any other fare. This includes unsweetened nut butters, like peanut butter and almond butter. I commonly hear nutrition experts cautioning against eating too many nuts because they are high in fat, calories, and “energy-density.” I have had a running good natured debate about this with a friend who heads a leading anti-hunger organization in New York. He is convinced that when he eats nuts he gains weight. I’ve earnestly explained that the dietary fats in nuts and seeds are exceptionally healthful and—together with their fiber, vitamins, minerals, and phenolics—form a nutritional powerhouse, one of nature’s crowning gifts for our well-being. I’ve described the evidence from long-term observational studies and numerous shorter-term trials that people who eat more nuts gain less weight over time; and that these results were confirmed by a large, five-year intervention proving that daily nut consumption reduces belly fat and waist size.

The takeaway is not to follow a single rigid food rule. It is to build more of your meals around protective foods—while recognizing that other choices fall along a spectrum. That shift puts nourishment, rather than restriction, at the center of eating well.