"This level is consistent with those set by other countries and international bodies that set food safety standards," the FDA said.
In addition, foods that claim "no gluten," "free of gluten" and "without gluten" must meet the definition for "gluten-free," or the FDA will consider them noncompliant with the rule.
Many foods now labeled "gluten-free" may already meet the new standard, the agency pointed out.
"We encourage the food industry to come into compliance with the new definition as soon as possible and help us make it as easy as possible for people with celiac disease to identify foods that meet the federal definition of 'gluten-free,'" Michael Taylor, FDA's deputy commissioner for foods and veterinary medicine, said in a statement.
Buying "gluten-free" has become something of a fad. But for people who don't have celiac disease, gluten-free products can actually be harmful if consumed exclusively, one expert warns.
"People with celiac disease must adhere to a gluten-free diet, but people who are not afflicted with this condition put themselves unnecessarily at risk for nutrient deficiencies by banishing all gluten from their diet," said Dana Angelo White, a nutritionist and clinical assistant professor of athletic training and sports medicine at Quinnipiac University in Hamden, Conn.
Many people without gastrointestinal issues mistakenly believe that gluten-free foods are healthier or helpful for weight loss, White said.
In actuality, "many gluten-free products, including a variety of baked goods, are higher in calories than their [non-gluten-free] counterparts, which could lead to weight gain," White added. "That said, there are many healthy foods that are naturally gluten-free."