CAN’T QUIT YOU

Processed foods cause overeating — and substantial weight gain

“Once you pop, you can’t stop” goes the old Pringles slogan.

Anyone who’s ever pulled open a bag of potato chips knows how hard it can be to set it aside unfinished. A new study from the National Institutes of Health aims to understand why.

The “landmark” research, appearing in the journal Cell Metabolism, shows that “ultra-processed” foods may actually have something habit-forming in them, pushing people to overeat and gain more weight than those on a whole food or minimally processed food diet.

Previous studies have shown that eating a diet low in whole foods is linked to an increased risk of cancer, cardiovascular disease and early death, but these observational, self-reported studies could only show a correlation, so scientists could not directly attribute obesity and illness to a diet of processed foods.

The NIH’s first-of-its-kind, strictly controlled trial revealed that those on an ultra-processed diet consumed 508 more calories daily on average — leading experts to speculate whether these foods are somehow addictive — and each gained about 2 pounds during the twoweek period. Those on the unprocessed diet actually lost about 2 pounds each.

“I was surprised by the findings from this study, because I thought that if we matched the two diets for components like sugars, fat, carbohydrates, protein and sodium, there wouldn’t be anything magical about the ultra-processed food that would cause people to eat more,” says lead author Kevin Hall of the National Institute of Diabetes and Digestive and Kidney Diseases at the NIH. “But we found that, in fact, people ate many more calories on the ultraprocessed diet, and this caused them to gain weight and body fat.”

Researchers think that participants on the processed diets might be consuming more because they also ate more quickly than the others. Processed foods also tend to be more calorie-dense, so less is required to provide the same amount of energy as unprocessed foods.