One year ago, the Food and Drug Administration (FDA) unveiled a plan to set guidelines for packaged foods claiming to be free of gluten. The FDA regulations, which are voluntary, take effect today and stipulate that any packaged food labeled "gluten-free" must contain no more than 20 parts per million of gluten.

While companies cannot be forced outright to disclose whether a product contains gluten or not, the standard could help establish a uniform definition of "gluten-free" for consumers and also help hold accountable those food manufacturers that promote their products as gluten-free.

Gluten is a protein found in wheat, rye and barley. People with celiac disease, an autoimmune disorder that prevents them from digesting gluten, must avoid it completely in order to prevent serious damage to the digestive tract. In addition to consumers who have celiac disease, a  growing number of Americans have chosen to follow a gluten-free lifestyle, contributing to a booming market of gluten-free products that is expected to surpass $6.6 billion by 2017. However, most nutrition professionals agree that such dieters should undergo medical testing to determine if a gluten-free eating plan is truly necessary.

Dana Angelo White, MS, RD, ATC, is a registered dietitian, certified athletic trainer and owner of Dana White Nutrition, Inc., which specializes in culinary and sports nutrition.