Healthy
When it comes to food, it's really hard to get concise answers about how healthy or unhealthy certain things are. One of these matters being number of meals. You'll get all sorts of mixed opinions from "experts" each having their own mix of beliefs.
Based on the mixed information, there seems to be a general trend towards: one meal a day is probably possible, but you'll need to make sure it's extremely balanced and enough for a whole day. Both very challenging tasks.
I was mainly curious about this topic due to a friend that somehow only eats one or two meals a day.