I was diagnosed with Type 1 at 33. It happens.

First, I'd encourage them not to look at this like, "He's diabetic, so we need to throw out all our old recipes." For me, it was just much more about adjusting the proportions of what I ate, and - to be fair - eliminating a few things.

A typical meal for me before would have consisted of a piece of meat, some starch, and some vegetables, in roughly 50% / 40% / 10% proportions. Since my diagnosis, I've flipped my starch and vegetable ratios - my meals now are mostly meat and vegetables, with maybe a little bit of starch (although, many meals, I avoid them altogether. It's just not worth cooking a tiny bit of potato).

I just think they'll be a lot happier if they look at ways to modify their old standby meals to incorporate more vegetables and less starches, than if they go out looking for a whole new set of meal plans. Getting a diagnosis like this can feel really disruptive, so minimizing the amount of newness in everyone's life may make the adjustment a lot easier to manage.

Seperate carb from vegetables and meats. BIL can take more veggies, meats and less/no carbs. Or, make him a plate before adding any carbs. BIL needs to learn cooking for his condition.
Vegetables stir fry with meats, vegetable soup, quinoa, multigrain rice, vegetables from different ethnic grocers
Good chance to teach kids about health and food

The low carb/low glycemic index is good to think of. I've been a diabetic for nearly 30 years. It really is about eating healthy and balanced. I eat a lot of lean meats. I eat a ton of vegetables. I eat carbs but go light on them. High fat foods, especially when combined with carbs, can make your bloodsugar go a bit crazy. Things like pizza are really hard on my body. I make my own to make it leaner. I usually stick to a slice and a side salad. I would really encourage your BIL to keep track of his bloodsugar an hour or two after meals. See how different foods affect him. I don't do well with some weird things. I do fine with pears but terrible with apples. Its a big learning game. He will learn his body and learn how to eat. I eat the same things everyone else eats, I'm just careful about how much of things I know are risky to me.

My husband was diagnosed with type I diabetes just less than 2 years ago, at age 39. I find the diagnosis hasn't massively changed the way we eat. We just be sure to balance all of our meals and snacks and choose higher protein, fiber and lower starch/sugar and fat options, as much as possible, much of which we did already. Quinoa is a great option to replace rice, as it has much more protein. We throw hemp and or chia seed into as much as we can (cold cereals, oatmeal, muffins, smoothies, salads, hamburger meat, etc.), to increase protein content.

My blog has a diabetic-friendly tag on the left, which will give you some ideas. You can pick through to see which recipes might appeal to your kids. Once my husband began insulin, his sugars stabilized very nicely by following a well balanced diet.

I recommend this blog, especially for desserts. My boyfriend and father are both diabetic, so I've tried a lot these recipes.

http://alldayidreamaboutfood.com/

I would encourage your sister and BIL to watch Forks Over Knives and check out the McDougall Diet. If he has Type 2 diabetes, he can reverse it. Type 1, he can manage it better. It's a more drastic change in diet, but I'd think reversing his diabetes would be worth it :)

Diabetic cooking does not need to be complicated. A steak and vegetables is a very good diabetic meal. If the kids insist on having mac and cheese or other carb heavy options for dinner then move those dishes to side item status while keeping lean protein and veggies as the main course. It will teach the kids good eating habits and maybe over time the entire family can learn to scale back processed foods which tend to be high in carbs and added sugars.

Be careful of sauces though. You might be surprised to learn how much sugar is in ketchup, A1 and barbecue sauces.

Vegetarian diets are great for diabetics. Meat still has enough fat (if eaten on a regular basis) to affect diabetes.

Contrary to what most people think, fruits can still be consumed by diabetics. Just make sure it's fresh fruit, not dried, dehydrated or in a form of processed snack. Fresh fruits, while they do have sugar, also have fiber and other micronutrients that delay the quick release of sugar into the blood. Also, the serving size of sugar in a fruit does not compare to that in a processed food product.

Ditto to the above commenter on recommending Forks Over Knives.

I'm going to counter something that Anita83 said - vegetarian diets, unless you're heavily into salads, are extremely difficult for people with diabetes. A major strategy for managing this condition is reducing the amount of carbohydrates, ie starches, in your diet - that means that I tend to avoid having things like rice, pasta, and potatoes feature heavily in my meals. If I eliminated meat as well, that would pretty much relegate me to a big pile of vegetables and/or soy for dinner every night. BIL (and, it would be beyond cool if his name were actually "Bill"), is going through enough right now, being told that he needs to make major adjustments to the amounts of starches and sweets that he consumes - take meat out of the equation (I'm assuming BIL eats omnivorously right now), and he'll fail.

For what it's worth, beer has carbs - but generally much, much less than non-diet soda.

I'd recommend looking at the blog nomnompaleo.com. I've found tons of inspiration from the author's posts despite there being few recipes. After reading through a few posts, you may realize that cutting the carbs out of recipes is simple. (The trouble is not missing them when they're gone)

Go to websites like the American Diabetic Association and look for recipes if you like. It's one way to help you indentify ways to deal with lower carb cooking.

The big thing is to learn just what are carbs, including such things as milk, which I certainly did not think of as a carb food, and starchy veggies. Fiber is your friend.

Once you do a bit of looking around you will probably be amazed at how you can cook easily for the whole family. Beans as fiber, lean ground beef, onions, tomatoes and seasonings and you can make a great chili that satisfies everybody. The diabetic will be a bit more conscious of portions than you are used to, but it really is not impossible.

Also, avoid soda, and juices. If a diabetic wants an orange soda, you learn to go for a whole orange instead. I tend to avoid diet sweeteners completely. They just make you think you want something sweet and you soon get used to not adding sugar at every turn.

There are loads of recipes online and learning to read nutrition labels will become second nature.

My boyfriend was diagnosed as diabetic a few months ago, so we've just gone through this as well. I've used many of the recipes from this site and we've loved them: http://www.preventionrd.com/. This is another good site: http://www.skinnytaste.com/ (look on the right side for tags to search by and click "low carb recipes"). The most helpful thing our RD told us was to divide a reasonably-sized dinner plate in half in your mind; one of the halves should be filled with non-starchy veg (not potatoes, peas, or corn). Then divide the other half into halves again; one of those sections should contain lean protein of some kind and the other should contain a high-fiber carby thing. So, for example, a big salad with some grilled chicken on it, a vinaigrette dressing, and a piece of whole wheat bread would work. A stir fry with some lean meat in it and a bit of brown rice is another possibility (check the rice package--15 grams of carb is a serving). If you want pasta, sure, but make it a small portion of whole wheat pasta and serve it with lots of veg in the sauce or on the side. Or sub quinoa for the pasta, as it has more protein. If you want a snack, make sure it has some protein to balance any carbs; plain Greek yogurt with some cut-up fruit is one example.

If your insurance will cover a session or two with a diabetes educator or RD, I highly recommend you go for it (the diabetic and whoever does the cooking should both go). It was a big help to us.

Everyone has their own advice, which is to be taken as a helpful hint, not fact. The ONLY WAY the brother in law is going to be able to eat healthy is to figure out what he can eat based on meticulous blood sugar readings after meals. He will have to learn how to figure out when his blood sugar reaches it's highest spike after a meal. For some people, it will be an hour, others 40 minutes, and some find it takes two whole hours.

What he may be able to eat safely for him could be vastly different than any other person with diabetes. There are general guidelines but they are often wrong (the ADA's amount of carbs isn't really healthy for a non-diabetic and is generally harmful to type 1s, 2s and 1.5s.)

Vegetarian diets are hard for most diabetics because most of us have very few choices to begin with, so if we end up eliminating grains, for example, it's tough to then eat only vegetables and some fruits.

The bottom line is that trial and error is going to be the only way to safely proceed in a way that forms a diet for life for anyone who has recently been diagnosed. Until someone knows what their own, particular body likes and doesn't like, all of this is anecdotal.

(I'd also caution those who say Type 2 can be reversed. Yeah, it can. Absolutely. But for some, there's a heavy genetic component that can't be overcome without severe deprivation to the point of other health issues coming into play. It sucks, but that's the way it is for some people. I don't like the idea of Type 2s being made to feel like failures because they can't reverse their own case of diabetes.)

Spaghetti squash! I just made this for the first time last night and I am in love. Plus it was super easy in the microwave. I'm ready to throw out my pasta forever.

Fromage is definitely one the ball with this one. My own brother is diabetic and his main trouble is keeping his blood sugar Up, not down. He's insulin dependent and has to carefully count his carbs- for him, low carb is Really not the answer. Also remember that being diabetic doesn't necessarily mean you suddenly can't eat normal food, even sweets.