Nowadays, you should be so lucky if your only worry is serving a meatless entree. Trying to keep the Atkins-loving or organic-only crowd happy is a lot more taxing . . . and etiquette-wise, they're within their rights.

According to the esteemed Debrett's Guide to Etiquette and Modern Manners, hosts have "learned to be sanguine about guests" nutritional requirements and will try to be accommodating". But when a restricted diet is one of medical necessity, it's vital that you get the menu right. If your guest is a diabetic, a coeliac or has a severe food allergy, what then?

DIABETICS
It's thought that some 250,000 people in Ireland have diabetes, with many more undiagnosed and these numbers are expected to double by the year 2010. The condition is marked by the failure to produce enough insulin, which is needed by the body to use glucose as energy. As carbohydrate is the primary source of glucose, diabetics have to control their intake of it . . . too much will cause high blood sugar levels, leading to long-term complications, and not enough carb can cause blood sugars to drop, causing disorientation and . . . potentially . . . coma.

The good news is that planning a meal for diabetics is exactly the same as devising one for anyone else wishing to eat healthily. It should be balanced, varied and avoid obvious sources of sugar. The diabetic diet is also very much in tune with the popular Glycaemic Index diet, first developed for diabetic patients, with its emphasis on slow-release energy food. When celebrity chef Antony Worrall Thompson was diagnosed with Syndrome X, a pre-diabetic condition, he embraced the GI diet in the hopes of losing some weight and possibly reversing his condition.

Worrall Thompson says he's not a difficult dinner guest. "I wouldn't be so rude as to tell my hosts what I'd like to eat but if they were happy to listen, I'd have something like crab salad, which is fine because there's no GI rating for protein, or I'd like some fresh shellfish.

"For the main course, instead of using old potatoes, use new potatoes, don't have any heavy root vegetables like parsnips or swede and give me some green veg." His hero food is puy lentils and when he does fall off the GI wagon, it's always for restaurant bread. "I used to love honey tartlets, but they've gone out the window now."

Don't think that all desserts are out of the question for diabetics however. Margot Brennan of the Irish Nutrition and Dietetic Institute (INDI) says it depends on what you choose. "Obviously, avoid sugary desserts such as ice cream in chocolate sauce. But there wouldn't be any major problem with having a small amount of something like a fruit crumble and using Canderel to sweeten it."

Dish up: A good balance of lean protein, heart-friendly fats and complex carbohydrate, with plenty of greens. Something like pan-fried salmon with new potatoes and mangetout, followed by fresh fruit salad and low-fat cream would be great.

Watch out for: Timing. Ask your guest what time they like to eat at so you can schedule dinner around his or her insulin regime.

COELIACS
People with coeliac disease cannot eat gluten and therefore need to avoid wheat, barley, rye and oats. This poses no problems if you're serving a traditional meat, veg and potato dinner, but avoiding cross-contamination of gluten-free food is trickier. Chips, for example, are fine for your coeliac guest but you need to ensure that they're not fried in oil that has been used for battered products.

Be particularly vigilant with pre-prepared meals and read labels carefully to see if they contain gluten.

Emma Clarke Conway of the Coeliac Society of Ireland's advice is this: "Take what you would normally cook and find alternative solutions to anything that doesn't fit with the diet." Gluten-free pasta and a tomato sauce is one quick and easy meal solution.

Dish up: Simple fresh, unprocessed foods. Roast chicken and all the trimmings (minus flour to make a gravy) is ideal. A wide range of glutenfree foods is available and the Coeliac Society of Ireland (www. coeliac. ie) can give you more information on recipes and ingredients.

Watch out for: Condiments. Malt vinegar, many mustards, pickles, relishes and salad dressings are all on the danger list.

FOOD ALLERGIES
To a large degree, both diabetics and coeliacs self-manage their condition and will know what they can and can't eat. But someone with a severe food allergy must be able to completely trust their host, who in turn needs to be confident about the ingredients.

The offending food's inclusion in a meal mightn't be obvious but, depending how sensitive your guest is, a reaction to it can be lifethreatening. The most common food allergens are nuts, fish and shellfish, but others include strawberries, chocolate, milk, eggs and soy.

"A true nut allergy is a very serious condition, and even to have a bag of peanuts open in the kitchen around that individual could be enough to set them off, " advises Margot Brennan. "There was a case last year where a girl kissed her boyfriend who had eaten peanuts some hours earlier and there were obviously traces of them around his lips because she went into anaphylactic shock."

Becky Moffat, 31, discovered her allergy to shellfish a few years ago when a prawn dish caused her throat to swell and necessitated a trip to hospital. She now carries steroids and an adrenaline pen with her at all times. Managing her condition can be awkward at times.

"I recently went to a friend's party in a Thai restaurant and after checking the ingredients, they had to cook me a completely different meal."

While anyone can develop a food allergy at any stage in life, we're most susceptible to them when our immune systems are low. If you think that you might have a food allergyc, consult your doctor, who can determine if this is indeed the case.

Dish up: Something you're completely certain is safe for your guest. Ask them all about their allergy first and then have a look at www. recipelink. com/specialdiets. html for ideas.

Watch out for: The unusual suspects. If someone has a fish or shellfish allergy, remember that Caesar salad dressings and Worcestershire sauce often contain anchovies. If nuts are the problem, bear in mind that many bakery products either contain or have been in contact with nuts.