Is there any medical evidence suggesting a Kosher diet is better (or worse) than a non-Kosher one?
I don’t think there’s much difference in health.
Kosher also covers a wide range. It could be vegan, or filled with red meat. You could probably come up with a kosher diet that fits any diet – low carb, high carb, vegetarian, vegan. As long as you avoid the no-nos – pork, shellfish – and prepare the food properly, you can stick to most diets around.
No that I know of. In fact kosher meat, being salted during the koshering process, can be a problem for low sodium diets.
I grew up kosher and my dad was on a low sodium diet which was an issue. We also tended to drink little milk and not eat that much dairy since many meals had meat. I think we got less dairy than most kids my age.
That said, we also ate little processed food as much of it wasn’t marked kosher, so at least that was a positive, but that had more to do with what was available than kashrut per se. The cuts of meat tended to be higher quality as well.
A quick tip if you ever go to prison: tell them you’re Jewish and keep a kosher diet. Prisons don’t produce kosher meals in house. They order them from outside distributors and they generally taste better than the regular meals.
What about Halal meals?
My father, who was not Jewish, always claimed that this was the way to get better food when flying. I never tried it so does anyone know if it still applies - he was flying in the first half of the last century.
If you have gout, avoiding shellfish is a good idea.
Depending on the airline, the regular food is pretty darn good. It’s mostly on international flights, and US flights seem to rarely serve food anymore.
On average, a diet without bacon is probably healthier than a diet with bacon.
Kosher and Halal have quite a lot of overlap (some Muslims consider anything Kosher to also be Halal, except for the booze.) OTOH Muslims are allowed to eat almost any insects, which Kosher laws restrict to a few named species. But in practice most people don’t eat many insects.
On balance I doubt it makes much of a difference. You can have very healthy and very unhealthy diets in both systems.
But at what cost?!
I take it you are not in the USA 
Surely we have to take spiritual health into account, too. You may be God’s Chosen People but that guy is a jerk. 
I could never keep kosher because of my love of shellfish. And BBQ ribs. I could live without bacon.
Definitely better if becoming a Rabbi is a career goal.
This is true. Someone very close to me is in prison right now. She requested a kosher diet because it’s better and fresher. For example: Instead of soy burgers, she gets fresh beef hamburgers.
In our prison system, you can request and get general kosher, halal, & vegetarian meals, all by claiming religious or spiritual necessity. BUT if they check your canteen list and discover you’ve been eating foods not in accordance with those mean plans, you will lose that diet and go back to being served a general diet.
Medical diets will also be discontinued if the patient doesn’t comply with them. No sense in serving up a reduced sodium diet to a guy slamming pork rinds and ramen noodles with the seasoning packet on the side.
Telemark:
Obviously you’re talking pork, and I can’t tell you that pork ones aren’t better, but we kosher-observers certainly enjoy the hell out of our BBQ veal and beef ribs.
Actually, I prefer beef ribs myself, but when visiting my brother in Alabama they do pork BBQ and it is do die for. My folks never kept kosher, but their parents did, off and on. My mom cooked some wonderful pork spareribs growing up that became my oft requested birthday meal. I have no idea where she learned to make them but they were gooooood.
Honestly, I could live without pork. I’d have a real hard time dropping lobster.
Air France has never disappointed me. Even on a little puddle hopper from Paris to Ljubljana we got a nice sandwich on fancy bread.
But yeah, any situation where one is avoiding the crappiest of the crappy food, for any reason, is going to be healthier than a diet that doesn’t avoid that food.
Muslims can also mix meat & dairy, and I think they’re allowed to eat shellfish.