They’re up to 70% of the American diet. But the US has no policy on ultraprocessed foods

Federal guidance on the pitfalls of ultraprocessed foods, which likely play a key role in the US obesity epidemic, isn’t yet available. Here’s what’s at stake.

Twenty-year-old Sam Srisatta is giving a month of his life to science — research that could help shape the future of US nutritional and regulatory guidance about the ultraprocessed foods that make up nearly 70% of the nation’s food supply. By 7 a.m. each day in his hospital room, nurses record Srisatta’s weight and vitals. Bowel movement samples are captured for analysis. Some mornings, blood is drawn to test how his body reacts to the different types of foods he consumes. Other days, he lies in a bubble that measures his oxygen and carbon dioxide output to determine how many calories he burns while at rest. After each morning’s battery of tests is complete, Srisatta has 15 minutes to eat his breakfast before the food is removed, weighed and recorded. At lunch and dinner, he has a full hour to eat as much or little as he likes before the leftovers are whisked away to be measured, and additional vitals are captured. Then he is free to read, play video games, exercise with supervision or fall asleep. It’s a routine he and 35 other volunteers repeat for four weeks as they live inside the Metabolic Clinical Research Unit of the National Institutes of Health Clinical Center in Bethesda, Maryland — part of a unique randomized clinical trial designed to tease out the health impact of different types of ultraprocessed foods. “These are industrially manufactured formulations from refined ingredients and additives that you typically don’t find in your home kitchen or restaurant,” said Kevin Hall, a senior investigator with the National Institute of Diabetes and Digestive and Kidney Diseases in Bethesda, who is leading the study. Ultraprocessed foods typically contain combinations of sugar, salt and fats designed to maximize the “bliss point” of a food, making it potentially irresistible — much like the 1960s Lay’s potato chip ads starring actor Bert Lahr, famed for playing the Cowardly Lion in “The Wizard of Oz,” who said, “Betcha can’t eat just one.”