Right, the one-meal-a-day program is an extreme form of intermittent fasting.
You can also do a 16-8, where you fast for 16 hours (except water and coffee) and then eat only within an 8-hour window.
Or else a bit more strict 18-6, or 20-4 (smaller windows of eating) ... all the way to the one meal per day.
Intermittent fasting not only works to drop weight but it stabilizes insulin levels and also has a bunch of other health benefits, many of them scientifically proven now.