Avoiding Ultra-Processed Foods Might Double Weight Loss: Study

Trial Shows Those Who Ate Minimally Processed Foods Also Lost More Body Fat

- Alice Callahan

NEW YORK — New research suggests that people can lose more weight by avoiding ultra-processed foods, even those that are typically considered healthy.

The study, published in the journal Nature Medicine on Aug 5, is the largest and longest clinical trial yet to examine the effects of ultra-processed foods on weight.

Participants lost twice as much weight when they followed diets made up of minimally processed foods, such as pasta, chicken, fruit and vegetables, as they did when they followed diets with ultra-processed foods that met nutrition standards, such as ready-to-heat frozen meals, breakfast cereals, protein bars and shakes.

Federal officials have been sounding the alarm about ultra-processed foods, which account for about 70 percent of the food supply in the U.S. Health Secretary Robert F. Kennedy Jr. said ultra-processed foods were "poisoning" Americans and called them a primary culprit of high rates of obesity and chronic diseases.

Although numerous studies have linked ultra-processed foods to obesity, most have been observational, meaning they cannot prove that the foods directly cause weight gain.

Two previous trials found that adults consumed about 500 to 800 more calories per day when their diets were made up of ultra-processed foods than when they were made up of minimally processed foods. But those studies were small and short; the larger of the two, conducted at the National Institutes of Health, included 20 participants who followed each diet for just two weeks.

Critics argue that the results might have been different if the trials were longer, or if they included healthier ultra-processed foods.

The new study, though still small, was designed to address some of those concerns, said Dr. Samuel Dicken, a research fellow at University College London and lead author of the study.