Earlier quoted context omitted.
"Would really like to see this compared to another group with a similar level of calorie restriction but without the intermittent fasting." I think the answer to your question is total time inflamed (for lack of a better term). Eating and digesting appear to be an interrupt for many other processes, for obvious reasons. You divert a lot of resources and produce a lot of inflammation and depress a lot of immunity. Do…
Whereas my bro-science intuition tells me that asking my pancreas to produce all the insulin I need in a tighter window is much more taxing
Eating 3 balanced meals throughout the day might be marginally better or worse for the pancreas, but neither of these dietary choices trigger the panic-level insulin responses (which ultimately lead to insulin resistance and diabetes) that snacking on large amounts of refined carbs and refined sugars are notorious for.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2121099/ This study found that although there was higher blood glucose and reduced glucose tolerance in the morning for the group eating 1 meal a day, surprisingly they had less insulin resistance than the group eating 3. Other indicators of dietary/hormonal health were the same between groups. Same caloric intake of glucose between groups, and the 1 meal a day group shared the same evening window just like OMAD. This was a pilot study with small sample size (irritatingly the actual number isn't listed from what I can see) as well as a high withdrawal rate, unsurprisingly.