A lot of ultra processed foods are also ultra palatable foods so they’re high in fat, sugar and salt and very hard to stop eating. They’re also calorie dense so you eat past the point where you might become full with less calorie dense foods. I read this article earlier today and really liked it except that I thought the author went a little light on the judgement against this type of food manufacturing. Yes, we really do live in a world where it can be hard to both find and prepare “real” food, but the consequences of a western or specifically American diet have proven to be pretty intense.