You shouldn't just drastically reduce your food intake while dieting, right?

I occasionally see posts from people who practice one meal a day. I’m thinking of giving it a try myself; even if not to the extent of eating only one meal a day, I want to gradually reduce my food intake. Should I start with one meal a day right away, or should I cut back little by little? I’m curious if being drastic is better, or if taking a more relaxed approach would be better.