The feeding challenge should be to provide them with what they need/want, not to push it down their throats (as far as I understand, you have the Sims for that). That the human fatsplosion shows humans aren't particularly capable at keeping themselves healthy isn't really an argument that dorfs should be as stupid in that particular regard (although the creatures controlled with a fantasy setting of 0 and a [potential] realism setting of 100??? Maybe with a horror setting of 100?).
The fact that the dorfs currently are incapable of catering to their needs and desires does not mean it should or will be that way forever. Nutrition introduction more or less forces an improvement to be made in the food department, and one might hope the other parts will see some improvement as well with that overhaul. Personally I'd like to see need/desire satisfaction to be addressed before nutrition (call it "preparation" if you like). I guess Toady wouldn't want to spend more than a minimum effort in improving the current food satisfaction unless he has a clear path of minimal work to migrate that onto nutrition, though, and that basically requires nutrition to be figured out, which probably would work him up on that...
I've seen the remark linked, and I maintain that we've actually passed the peak by a little bit through the latest consumption rate change, but the difference is rather small, so we're still essentially at the peak, just not at the very top of the summit.
@mikekchar, posting while I wrote: We're probably at peak yield as well, as soil nutrition (a different task than food nutrition, tackled at the same time or separately) is probably going to lower production as well.
You don't actually want your dorfs to eat once per day: it's actually fairly easy to get an embark where it takes several days just to walk from the fortress to the lowermost work areas (such as magma sea operations). DF Fortress Mode operates on an accelerated time scale (72:1 or something like that vs Adventure mode). Even walking to the edge of a normal embark to pick up a log and bring it back is probably a task that takes several days. Thus, to eat once per day you'd probably have to change Fortress Mode speed to match Adventure Mode (and that would result in an enormous increase in the food demand as well...).