Can you be trusted to not develop or succumb to an eating disorder? My thought is, if you've had a *scare* about it in the fast, I would be very, very careful with IFing, as it could relatively easily slide into something else.
Personally, I don't call it an IF if I only eat at 3pm until 9pm, that's just a day. If I decide not to eat that day, sometimes, well, it's intermittent, and a fast... hence. Doink, IFing. I don't have any eating issues (that I am self aware of) so I just roll the dice. If I had a disorder, I wouldn't do it without my psych's ok.