After unprecedented nutrition study, personalized diet plans may be next

The big picture: More than half of American adults have at least one preventable chronic disease, which is often related to diet and exercise, according to the National Institutes of Health.

• People who eat healthfully have an easier time managing chronic illness, and generally live longer, per the Centers for Disease Control and Prevention.
• For years, American nutrition guidance has been generally applied: Drink water, limit your intake of added sugars, try to eat a balanced diet.
• But that guidance has never been able to take into account how drastically different individual responses are to what we eat, says Pennington Biomedical Research Center clinical science professor Leanne Redman, who's working on the new study.
• "Even when you provide people the same exact diet, the exact number of calories and carbohydrates, vitamins, proteins and minerals, we still see a wide variation in how people respond," she says.

Instead, researchers say what they're gathering from this study will create an unprecedented data set.

• "We're going to find out not only about what people are eating and how they respond to it, but in the context of their whole medical history, their genetics and their socioeconomics," says LSU Health New Orleans genetics professor Lucio Miele. "This will generate one of the richest databases on Earth of how people's diet interacts with their overall health and lifestyle."

What they're doing: The Nutrition for Precision Health project is funded by a $170 million National Institutes of Health Grant. It starts with the All of Us study, which is gathering data from 1 million Americans.

• From there, researchers will focus on 10,000 participants as they eat and report on their usual diets and another 1,500 people following a "prescription diet," providing blood, urine and stool samples for microbiome analysis, according to a press release.
• Then, 500 participants will get researcher-selected diets while staying at labs for observation.
• All three parts of the project are due by 2026, at which point the data will be processed with machine learning "to break down people into categories that will respond differently to different diets," Miele says.
• Researchers at West Point Academy are already working on the algorithms, Redman says, and final results are expected in 2027.

Yes, but: The study relies on a lot of self-reporting, but people are notoriously bad at being honest about what they're eating.

• "It's like going to the DMV and asking how much you weigh and how tall you are," Redman says. "It's the same when asking someone about their diet, specifically when they know it's a loaded question."
• That's why researchers are instead relying on smartphone apps and wearable technology, such as glasses that activate when you're chewing to snap a photo of your meal.
• Between the different parts of the study, Redman says, researchers will be able to extrapolate just how much cheating people really do when they self-report.

Zoom in: The study's very first participant was enrolled in Louisiana.

• "It's an opportunity to map the Cajun diet," Redman says. "There's no other place that eats like us. … We want to map the effects of the diet of Mardi Gras, or crawfish or grits and grillades, turtle soup. That's why we need as many people from Louisiana as possible to participate."

The intrigue: Participants will be able to access their own data during and after the study, Miele tells Axios New Orleans.

• "We won't necessarily know what it all means until the study is completed, but participants will get information back and be able to discuss it with their physicians and make informed decisions about themselves," Miele says.

Go deeper: Learn how to participate in the study at one of the contributing institutions.