Both mine are over a year old and still get three meals. All three are small meals. I'm a freak about bloat, hope to avoid it if at all possible, so I feel better giving more, smaller meals. That's just me though. It doesn't hurt to give three meals. Neither of my dogs refuse any meals and look forward to them eagerly.
In fact, if either dog misses breakfast (like for a vet visit when they need anesthesia), they will puke up bile. I think that morning meal is important, at least with my two.
Niko: American Showline GSD 5 years old
Rosa: American Muppet Dog (GSD/Border Collie mix) 5 years old