>The participants were allowed to eat as much as they wanted, but the diets had the same amount of calories total, and the same calorie density. The results are striking; participants eating ultra-processed foods consumed more calories and gained weight while the other group lost weight. [1]

Did they eat the same amount of calories or more calories? People will eat more of tasty food and less of bland food. You could get the inverse result by giving bland ultra-processed food and tasty unprocessed food.