I think it is fascinating and instructive that the Word of Wisdom (D&C 89) contains things that are accepted and enforced in our time as commandments, and that are included in the requirements of temple attendance, as well as things that are accepted generally in the same spirit in which the original revelation is worded - as "words of wisdom" but not clearly definable prohibitions.
When this is discussed my members, the conversation often turns to meat consumption, but I see the question about meat as the same as a discussion about
grains and fruits (and sleep, although that is not addressed in the Word of Wisdom). Healthy practices vary person to person and simply
cannot be codified properly into one common standard that can be
measured for temple attendance or even simple obedience. As a people,
we can be Nazis about too many things already; the last thing I want is
for a local leader to be able to start keeping charts on each member’s
Body Mass Index, meat consumption, seasonal fruit decisions, etc.
In other words, I am fine with some portions of Section 89 being
measured according to the letter of the law and others being left up to
us as individuals to live according to the spirit of the law. After
all, we aren’t supposed to be commanded in all things and, rather, are
supposed to be agents unto ourselves – and I think the Word of Wisdom is
perhaps the best practical example of how we can be commanded in some
things and not in others, even in the same general area.