Such persons in my opinion should not partake in this practice.
It does not make sense to crave for an healthy life and groan through it all. If you can never come to adjust to the lifestyle, then substitute it for other health methods that can give you same results.
The issue of intermittent fasting good or bad outcome will always be as a result of your follow through, meal situations and current health status.
If other health departments in your life adds up then intermittent fasting would surely be good for you.
But if not, then work on the other areas in your life before embarking on IF or it would be a very bad experience for you.
And before I go, don’t involve yourself with this practice if sick, treat your ailments first.