How to cook for a diabetic without making the other guests suffer

I think the best solution is to avoid pre-mixing or pre-saucing anything. If you bring out a big bowl of pasta tossed (or topped) with sauce, the only way to get sauce is to eat pasta. Imagine instead you bring out:

• a big bowl of pasta, perhaps tossed with a little oil to keep it from sticking
• a bowl of brown rice
• marinara sauce
• alfredo sauce
• olive-oil-grilled veggies (cauliflower, carrots, eggplant...)
• grilled lean meat (chicken breast?)
• mashed potatoes
• a nice loaf of bread
• a big green salad

Some people can have pasta and sauce. Some people can have meat and sauce. Some people can declare marinara sauce to be as close to a vegetable as they want, while others can eat veggies with rice or pasta and ignore the meat. If your alfredo is vegetarian and your marinara is vegan, you're covering a great deal of ground - diabetic, non-gluten, vegetarian, vegan - with one feast.

Personally I would avoid gluten-free pasta, or any kind of substitutions that are supposed to resemble something else. In a big dinner, you want to make it easy for people to know whether to avoid something or eat it. You also don't want people saying things like "ew, no, this is the fake pasta, please pass me the good stuff!" and making the person with a special diet feel bad.

You can buy prepackaged low-carb pasta (or gluten free pasta) if you want to make a quick dish. For a healthier option, you can make zucchini noodles. All you need for this is a lot of zucchini and a mandolin or spiral slicer. "Zoodles" are so easy to make and delicious with pasta sauce and fresh cheese! I make these a lot and oftentimes add caramelized onions and red peppers for more flavor. They're always a big hit with my family. An easy recipe can be found here on the nomnompaleo website.

Besides pasta, there's tons of other low-carb, sugar-free dishes you can make for yourself or even large groups. The best way I know of finding these recipes is to google what I want (ie: 'pizza' or 'meatballs') and add any dietary restrictions to the search (ie: 'low carb pizza' or 'low carb meatballs'). This will bring up all sorts of recipes for you to look over and choose from. Nutritional info & serving sizes are usually included.

EDIT: About the mashed potatoes, there's a lot of low carb recipes that call for cauliflower. I'm not a fan of those recipes, and use boiled jicama (mexican potatoes) instead. They don't get as soft as potatoes, but when you take them out and pop them in a food processor with some heavy cream, salt, and garlic, they are definitely the closest things to real mashed potatoes that you can get. 1 cup of boiled jicama has about 5 grams of net carbs, so these are perfect for low carbers & diabetics alike.

I agree with the above. I'm diabetic and cook normal meals for guests. I generally stay away from white sugar, flour, and rice. You can make nearly anything and avoid those three things. I'm sure your diabetic guest knows how to limit his/her carbs.

Spaghetti squash for the pasta.... see Replacement for pasta that is natural and fairly low carb

For mashed potatoes, some people like mashed cauliflower. You can find many recipes by googling ,

wounder if there are other veggies I can mash to come up with something like mash potatoes but less starchy

No, there isn't. Mashed potatoes don't have much aroma, and if they did, no substitute would have a potato-like aroma. What makes mashed potatoes be that way is the fact that they are made up with starch. For a really good mahsed potato dish, you even have to choose potatoes with the right type of starch.

There are tons of vegetables you can cook and mash. But what will make the result similar to mashed potatoes will be the starch content. Whatever you find that is mashed-potato-like will also be high in starch. Whatever you find which is low in starch will also be pretty far from mashed potatoes.

Are there any techniques commonly used to make dishes with a lower hypoglycemic index?

There are no magic ones which turn low-glycemic-index food taste like high-glycemic index food. The only technique is to 1) choose food which is low in carbohydrates and 2) process the food as little as possible. For example, a whole apple will have a much lower glycemic index than apple mousse, and apple moussee will be lower than apple juice. If you think that your guests will only enjoy foods high in processed carbohydrates, there is no way to lower the glycemic index of these foods.

You can try looking for substitutions which roughly mimic the high starch food, such as "spaghetti" made from vegetable juice thickened with hydrocolloids. They can have a similar appearance, but will lack both the texture and the physiological response (e.g. a feeling of fullness) common to high-starch foods.

I think there may be a mistaken assumption about the glycemic index of the pasta dish and mashed potatoes. If you were eating pure pasta with nothing else or mashed potatoes made of mashed potatoes and nothing else than they would be high gyclemic index foods.

However, fat reduces the glycemic index of food a lot (so does fiber). Alfredo sauce has a lot of fat, as do mashed potatoes as commonly made with plenty of butter beaten in. Therefore the glycemic index of these foods may not be anywhere near as high as you think and a substitution in this case may be completely unnecessary.