Note that some artificial sweeteners produce an insulin response like sugar - which leads to calories converted to fat.
Also, I wonder about fiber and other carbohydrates. Fiber moderates carbohydrates of all types and prevents glucose spikes (and crashes). and other processed carbs/starches can be very similar to simple sugars - breads, pasta, rice, potatoes, cereals, etc.
Did a ctrl+f on this page to see if anyone had mentioned fiber. Absence of fiber is probably the key characteristic of "ultra" processed food. Foods with fiber are lower in calories, take longer to eat, increase satiety, and moderate glucose response. People are looking all over for scapegoats ("plastics!"), but fiber barely gets any attention.
But yes[0], while metabolic pathways have been identified where artificial sweeteners certainly could cause insulin issues, RCT's have failed to find this effect expressed in vivo.
Artificial sweeteners do cause notable changes in gut biomes, and the effects of that are unknown.
Right, but for the purposes here, it's probably enough to say that several artificial sweeteners are unexpectedly bioactive. As such they perhaps are doing things that are undesirable.
Also, I wonder about fiber and other carbohydrates. Fiber moderates carbohydrates of all types and prevents glucose spikes (and crashes). and other processed carbs/starches can be very similar to simple sugars - breads, pasta, rice, potatoes, cereals, etc.