That's because they were not done for any good reason. By this I mean some person with mental problems started a cult told everyone to start fasting for "religious" reasons and people followed. Obviously we don't pay much attention to that these days. Just like we don't investigate the scientific benefits of sanctified food.
Barely worth responding to, but many of dietary restrictions imposed by early religions had very real benefits, such as Hebrews with pork (Trichinella).
It's beyond foolish to flippantly dismiss knowledge offhand because you dislike or are prejudiced against the source.
They may have had real benefits, but not scientifically understood benefits, and by now they are followed for religious tradition rather than because research has been done showing that it's a good idea. Pork is a good example, as far as I'm aware there aren't people recommending avoiding pork (while still eating other meats) for health reasons, just for religious reasons.
The person you replied to worded it rudely about religions, but I agree with his overally point in that I want to hear from scientists not religious leaders when it comes to health advice, regardless of how sensible the religious advice was when it first came into existence.
Considering all the other problems that have been caused by religion, I think being a bit critical of it is more than justified. I am not going around oppressing millions if not billions of people with bad ideas that are quite literally based in mental problems.
I'm an atheist, and I have many criticisms of many religions, but imposing dietry restrictions on those who wish to follow them isn't one of them. I'd also suggest that being constructively critical in a debate is fine, posting comments like yours that I refered to is only going to make religious people dislike you and won't change a single opinion, other than making you and other people who already agree with you feel smug.
(For the record, while I wouldn't necessarily agree with a statement of "religions have done more good than harm", I do think they can and have done good in some areas. A religion that promotes good morals and tolerance, without preaching the negatives that you and I dislike, is fine with me, even if I don't personally believe in everything they believe in. And on a personal note, I'm thankful for some of the wonderful music and other art that religion has inspired and/or funded over the years.)
I don't have sources handy, but one of my friends doesn't eat pork because he believes (based on some source or another) that it is worse for his health than other meats (including beef).
I never asked him for his sources because it doesn't really affect me. The only reason it came up is because he was eating dinner at our house one day.
Even a broken clock is right twice a day. Same I guess goes with a broken brain. I mean I guess you could say that mental disorder for instance hypochondria has benefits now and then so I guess we can justify all the other problems it causes for a few solutions that it provides, due to the hyper-vigilance of the individual against preconceived threats.
