Fat processing depends on PGC-1a
If intolerance to fatty meals and fasting is relevant for you, this paper may give a hint about “why it can happen”.
I’m working on notes about PGC1a and its involvement into energy regulation. Will share the first version soon.
Impaired activation of PGC1a seems to be a result of NAD depletion and low methylation potential primarily. Maybe will find some other factors.