God doesn't want his people shaving their heads or tattooing themselves in honor of the dead because we are to be holy, and affinity with death is inherently unholy.
Deuteronomy 14:1-2

The flesh of animals that are forbidden to be eaten are disgusting to God. They aren't forbidden for health reasons, even if there might be good health reasons for not eating them. They are forbidden because God wants to be close to his people, and he is disgusted by their meat.
Deuteronomy 14:3