I cannot speak for other religions but Judaism certainly presents some challenges for a person with Diabetes. I grew up traditional orthodox and became more observant in my teens. What that meant throughout my formative years was strict observance to the dietary laws (kashrut), building a temporary dwelling on Succot, fasting on Yom Kippur, cleaning the house for Passover (including changing over the the "passover set" of crockery, pots and pans, and cutlery, and eating so much eating.
Someone once described the Jewish festivals as "Some people tried to kill us, we survived, lets eat!" This appears to be mostly true, along with some other crazy things too.
So lets start with just the eating. Every Friday night the Shabbat (the sabbath) starts and after evening prayers there would be a meal, often with guests and usually at least 3 courses. Standard meals growing up in the UK would be something like:
Starter: one of Smoked salmon/Chopped liver/ Houmus and dips (with Challah - the traditional platted loaf, very tasty but white flour and often sweet)
Soup: Chicken soup (Jewish penicillin - NB it does NOT cure diabetes) , with coutons and vermicelli, and more Challah.
Main course: Roast chicken, roast potatoes, vegetables and salad
Desert: one of Ice cream (non milky - I will get to that in a minute) / sorbet / mouse / pie
If it was just the nuclear family it might not be as extravagant as that, and there were of course some variations but the more guests the more people. And more often than not there were guests. Either we went to another family or we were in with one. On Shabbat morning there was a Kiddush after services (a pseudo communal meal - ranging from snacks like crisps and nuts and pickled or chopped herring to sandwiches and sometimes even hot food). After finishing at the synagogue we had another meal, usually cold meats and salads (as there is a prohibition of cooking on Shabbat). The prohibition of cooking does not extend to something cooked on continual heat since before the Shabbat starts on Friday evening. Which is where we get Cholent from, a delicious meat stew with potatoes and other vegetables. Everyone has their own recipe and they range in style. The Sephardic tradition - Eastern and Spanish (I am from the Ashkenazi tradition - European) has a similar thing with rice called Hamin.
As a student we regularly had 10 - 15 people for Friday night dinner and again for Shabbat lunch. There were a lot of Jewish students in Manchester and once we gained a reputation for catering they would call us up (before hand - no using the phone on Shabbat) and invite themselves over.
The one thing to mention is that there really was not much alcohol involved, sure when we were students there was a bit more than with my family but honestly I did not grow drinking at these meals, nor did I see the adults consuming alcohol either, certainly not in any quantity.
I did not grow up with Diabetes myself, but my brother was diagnosed when he was 13 and I was 15. I remember every Shabbat meal out at friends when the desert came out. My brother taking some, and my mother asking "Are you sure?" and the irritated reply "I asked what was for desert and took extra insulin". I don't doubt it was hard for him, so much food and estimating the right amount of insulin to take must have been hard, and then sticking to eating the right amount of food too.
I wont lie, cooking and eating together as a family, extended or otherwise, or a group of close friends has a lot of merits. You eat slower, you know what is in your food. We never bought much processed or prepared (I mean no sauces, no pizzas, no microwaveable meals) food growing up or as students. The strict laws of kashrut make this very difficult. You must only have Kosher meat, not mix meat and milk products, even vegetarian products cannot always be relied upon. As a result things were cooked from scratch. Less additives, you know exactly what you are eating. It HAS to be healthier. Its just the quantity, and something I have always suffered from second helpings. I might estimate for a plate of food, but if its delicious and there is more I will go back for seconds. But I didn't estimate for that. Getting it right takes practice. But being involved with food helps a lot.
I must add that there is a very important law in Judaism, and that is Pikuach Nefesh. The commandment to save someones life, be it your own or someone elses. It extends to protecting ones health in many ways too. This is very important. It means that if there is no kosher sensible alternative I can eat what ever I need to stay alive. In fact any commandment (and there are many) can be broken in order to protect the health or life of an individual. The Rabbi of my community would drive kids to hospital on Shabbat if they fell and broke their arm. There are somethings that cannot be done to save a life, like kill someone else, but otherwise most things are fair game in an emergency.
I have been cooking Friday night dinners since I was 14 and unsupervised since I was 15/16. Since then I have expanded my repertoire and I still have a kosher home. Mostly I would say that Kashrut itself does not pose a problem with living with Diabetes, if anything strict adherence can help, by having to do it all yourself. But the attitude too food is where the problem starts. My wife always says her family likes to show love through food. Its true, her parents and grandmothers are fantastic cooks. And there is always leftovers to take home to put in our fridge.
Often on a Friday night with guests I am so busy that by the time I sit down to say the blessings before we start I have completely forgotten to test and take Insulin. I usually remember half way through soup. Its not the end of the world but it is frustrating. Everyone is eating and I am busy swapping needles, and pricking my finger. Over the years I have gotten better at estimating and if we are out I am not afraid to ask whats in something. At one family who knows me well, I will be taken aside and and given a guided tour of all the food before hand so I know what I can and cannot eat.
I am thankful for what I have got from Judaism but its not always easy on the Diabetes.
Live long and healthy