Ask many Christians, especially those that balk at reading the book of Leviticus, why God established the dietary laws for the Jewish people, laws we call kosher, and they will give a quick answer: it was for health reasons. Pigs carry trichinosis. Lobsters and catfish are bottom feeders. Many raptors are carrion eaters. Ask many of those same people if they keep kashrus (that is, if they eat only kosher foods) and they will admit that they like pork, cheeseburgers, or pepperoni pizza. If you carry the conversation further, the next question is probably, “why don’t you follow those laws, if they were for health reasons?” Here you may get a variety of answers. Some will simply admit that they do a lot of things that aren’t exactly healthy. Others will point out that the Law of Moses was given while they were in the desert in a time when refrigeration, sanitation, and the United States Department of Agriculture were not available or not as advanced as they are today. But is that the reason?
If the laws of kashrus were strictly to keep the Jewish people healthy in the desert, then why did God make them permanently binding on the Jewish people? God did not repeal those laws when they entered the Promised Land, and were no longer desert nomads. He did not repeal those laws when refrigeration became more advanced, or when scientists learned about bacterial, viral, and parasitic infections. For the Jewish people, or at least those who are strictly observant, those laws continue in effect today and forever.
If the laws are simply because kosher food is generally healthier, then there is a problem. Many nations whose cultures regularly eat non-kosher foods have longer life spans and generally healthier populations than those nations or areas that keep kashrus. The Japanese are among the healthiest people in the world, in spite of a diet that is strong on pork and non-kosher seafood. Further, there is no scientific evidence that camel meat is any more likely to contain parasites than mutton or steak. Catfish and crabs are bottom feeders, and more likely to eat just about anything; but sharks and whales (included because they are swimmers, even though they are not fish) are much more selective in their diets. Vultures and corvids (crows, ravens, and jays) eat carrion; but hawks, eagles, and ospreys eat live prey. (And lest anyone argue that they generally eat unclean (non-kosher) animals, ospreys keep kashrus better than many Jews.)
But what about forbidding the mixing of meat and dairy? Is it not true that they are digested at different rates and so it would be healthier not to mix them? Yes, they are digested differently, but there is no evidence that combining them makes one any less healthy, all other things being equal. It should also be pointed out that this is a rabbinic interpretation of a law that appears to be more about being humane than healthy. “Thou shalt not seethe a kid in his mother's milk.” (Ex 23:19; 34:26; Deut 14:21) The prohibition against mixing meat and dairy appears to be more about preventing a violation of this humane law than it is about digestion.
If the restrictions of Exodus 11 are not primarily for health reasons, then why did God place those restrictions on the Jewish people? If one reads the entire chapter, it becomes evident that the laws of kashrus were placed on the Jewish people simply because they were the Jewish people. It was not to make them any healthier than the nations surrounding them; it was to make them different than the nations surrounding them. The same could be said for circumcision, sabbath law, or even limiting the offering of sacrifices only to the tabernacle or, later, the Temple. Does God say any of these are for health reasons? No. His justification is that they were a select people.
For I am the LORD your God: ye shall therefore sanctify yourselves, and ye shall be holy; for I am holy: neither shall ye defile yourselves with any manner of creeping thing that creepeth upon the earth. For I am the LORD that bringeth you up out of the land of Egypt, to be your God: ye shall therefore be holy, for I am holy.
Ultimately, this should be our justification for anything we do.