For most families, the holidays are centered on meals together, and with so many allergies out there, it may seem impossible to feed everyone. But have no fear, thanks to Whole Foods' and many other groceries' "allergy friendly" sections, it's actually much easier to satisfy everyone's allergy needs than it used to be.
The simplest way to plan for a large gathering is to ask your guests whether they have any allergies. Make sure to list them down on paper so you won't forget any of them. From there, you may want to ask whether they eat meat or fish in addition to having any allergies, because you may make the perfect gluten- and dairy-free pork chops for your nephew only to discover at mealtime that he's vegan, too!
Once you're clear with everyone's dietary restrictions, you can head to your local supermarket, or even order online at http://www.tailormadenutrition.com, where you can custom order the products and meals that are perfect for you. In addition to that, you should ask your guests whether they have any brands they would recommend. Most likely, if they've been dealing with the allergy for an extended period of time, they have many brands and alternatives that they're comfortable eating. Once you have that information, you can order most products from Amazon.com.
If you decide to do the shopping in person, ask an attendant at the grocery to point you in the right direction. Often, there are the following sections to help organize and make everything a little easier to find: "gluten-free," "dairy-free," "soy-free," "peanut/nut-free," etc. Make sure to read the ingredients for every product to make sure they're aligned with what the outer packaging says. Look for certified symbols on the front that can help shorten the process -- e.g., GF = gluten-free.
If you're wondering where to start with recipes (before you even head to the grocery), there are dozens of food blogs that cater to any and every allergy out there. For gluten-free recipes, check out http://www.cookingglutenfree.com, and for dairy-free meals, head over to http://www.dairyfreecooking.about.com. That should get you started, but remember that a lot of the allergy-friendly brands will have alternative solutions to most standard, traditional ingredient lists on the back of their package or on their own website.
Ultimately, your guests will feel extremely taken care of if you make the effort to satisfy their dietary requirements, especially around the holidays when they, too, want to indulge in their favorite comfort foods with family and friends! If you're really struggling to find recipes that will suit them, the best way to solve that is to either ask them to bring a dish they know they can eat or have them send over some recipes of their own. It will mean a lot that you've taken the time to ask, especially because some people still treat those with food allergies as being "high-maintenance" or "hard to deal with," when the allergy sufferers are only trying to take care of their health.
For more information about food allergy icons, head to http://www.foodprotection.org, where there are some helpful downloadable charts of food icons.