He's downplaying the role that the body has in regenerating and healing itself with IF. Not sure there is any real research to back it up nor deny his claims though (or at least I have not come across any). You could go back to the old Mattson 1meal vs 3 meal study with IF and how 1 meal a day people had higher fasting am insulin...but there are flaws to that as they had complete "carb bomb" meals once a day and then only took fasting insulin in the AM....where later in the day it probably would have been lower. Not a perfect study but does shed some light on at least trying to eat moderate and more often than 1x a day.
I don't eat like it's Thanksgiving on a daily basis or weekly basis...so not sure that's a great comparison. One should be able to tell what is or is not working....as if you increase insulin resistance then you will see more "fat" gain vs loss...if you are leaning out then I guess it's not as damaging as he states. Only other way would be to monitor fasting insulin.
Since exercise also increases insulin sensitivity, the results may differ when talking about sedentary individuals vs active ones. Too many variables to consider.
Comes down to the same saying....IFOC (IF on Crap) isn't a good idea.