So, the conclusion of the study isn't particularly surprising, but it sounds like a reasonably well controlled cross-over study that shows that just eating better may be the key to keeping our waistlines from exploding.
https://www.npr.org/sections/thesalt/2019/05/16/723693839/its-not-just-salt-sugar-fat-study-finds-ultra-processed-foods-drive-weight-gain
https://www.cell.com/cell-metabolism/fulltext/S1550-4131(19)30248-7 (can access the PDF here as well)
It sounds like the study gave people access to about 5400 calories per day through their meals or snacks. The meals and snacks between the two arms were matched for macronutrients and calories, and it was up to the individual to eat as much or little of what they were given. Those on the processed arm ate about 500 calories per day more, and subsequently gained weight while the other arm lost weight.
While the study did match available calories/macros, those on the ultra-processed arm tended to eat more fat/carbs out of their available food more than they increased their protein intake. So can't quite draw a conclusion on IIFYM. Also, since they were allowed to eat differing amounts of calories, can't quite say if a calorie is a calorie no matter the source.
https://www.npr.org/sections/thesalt/2019/05/16/723693839/its-not-just-salt-sugar-fat-study-finds-ultra-processed-foods-drive-weight-gain
https://www.cell.com/cell-metabolism/fulltext/S1550-4131(19)30248-7 (can access the PDF here as well)
It sounds like the study gave people access to about 5400 calories per day through their meals or snacks. The meals and snacks between the two arms were matched for macronutrients and calories, and it was up to the individual to eat as much or little of what they were given. Those on the processed arm ate about 500 calories per day more, and subsequently gained weight while the other arm lost weight.
While the study did match available calories/macros, those on the ultra-processed arm tended to eat more fat/carbs out of their available food more than they increased their protein intake. So can't quite draw a conclusion on IIFYM. Also, since they were allowed to eat differing amounts of calories, can't quite say if a calorie is a calorie no matter the source.