I would tend to agree with Abshalom. The Jewish dietary restrictions make more sense to me as a "totemic" device, that is a way to distinguish themselves from the neighboring tribes. Of course, I believe that this has a secular origin, but nothing logically precludes a deity of separating her people from others through dietary restrictions and religious rites. So even if the dietary restrictions have no health benefits, it has no bearing on whether or not they are divinely inspired.
On the other hand, if it can be shown that a kosher diet is healthier than the standard Bronze Age Middle Eastern diet, it could either be from a god protecting the health of her people, or the result of pure trial and error experimentation on the part of the people over centuries.
In short, neither the health benefits of a kosher diet, nor the lack of any health benefits, have any relevance one way or the other to the question of Yahweh's existence.
I would point this out to kendemeyer, but I have no intention of reading Macht's study.