Ayumi kind of said something to Ogata about her weight, but not much. I think it was in a joint interview when Ogata mentioned that she doesn't eat after 6pm (or 5pm?). Ayumi was shocked and went "no way! you shouldn't do that!". I think Ogata doesn't look as bad as she did during the Ima Sugu promotions, but she's still very, very skinny.
However, it doesn't seem to limit her. And management doesn't do anything against it, either. Either she's going to stay that way or she'll collapse.
I heard Koda Kumi say she followed this diet trend years ago, and I've heard it mentioned by a Kpop girl group recently too. Not eating after 6pm seems to be a bit of a thing, but both Kumi and the Kpop girls were/are (?) healthier weights than Ogata has been, so she's likely doing other things in addition to not eating after 6 to be as skinny as she is.
I'm especially bothered by celebrities not maintaining healthy weight when they're in the public eye and could influence some poor fan or impressionable teenager to try and look just as thin. It's dangerous.