Agreed. I think it is correct to say that Ramadan fasting is intermittent but intermittent fasting is not Ramadan fasting, except the subset of fasting that is Muslims fasting during Ramadan.

I also think some others, among them Christians, fast completely.

Personally I am Christian but when I fast, the vast majority of the times it has been because I was bored or needed to focus, and I didn't punish myself by breaking fast once a day but just went without food a day or two or three until I became bored of that too or family demanded I ate.