I wrote a top-level comment (https://news.ycombinator.com/item?id=40816168 https://news.ycombinator.com/item?id=40816168) before I read yours, but from Tulleken

I wrote a top-level comment (https://news.ycombinator.com/item?id=40816168 https://news.ycombinator.com/item?id=40816168) before I read yours, but from Tulleken’s book, my understanding is the difference basically comes down to “would you ever make this in your kitchen, or no?” I didn’t include it in the comment, but in the book he elaborates that the proposed mechanism of action for UPFs is basically: people have innate homeostatic mechanisms to keep them from eating too much, but food scientists at major manufacturers (e.g. Kraft) have figured out how to use artificial flavors and modified starches and oils to control the flavor and texture of food with extreme precision (he gives the example of a company who made an ice cream that doesn’t melt at room temperature out of modified starches), and their goal is to sell you food, so they engineer their products to subvert your body’s feedback mechanisms and entice you to eat much more than you actually want. The presence of artificial flavors and modified starches is basically an indicator that the food you’re eating was produced via this process, and your body will probably react in the way the food’s engineers intended and crave more than is satisfying.