The authors singled out potato chips in particular. “We found potato chips to be one of the most obesity-promoting foods for youth to consume. Potato chips are very high in energy density (383–574 kcal/100g) and have a low satiety index, yet they are commonly consumed as snacks.” (Potatoes that aren’t cooked in oil, the authors write, are fine.)
Potato chips, sugar-sweetened beverages, and processed meats were also some of the foods most closely linked with weight gain in a 2011 study of 120,000 American adults. Unlike this Health Affairs study, that paper did find that adults who ate potatoes and even unprocessed red meat gained weight.