Can food allergies hamper your child’s growth?

Parents who eliminate foods that trigger allergic reactions in their children may be surprised by an unexpected outcome—impaired growth.

Recent research found that kids with food allergies had lower body mass index (BMI) than their non-allergic counterparts. Scientists believe that removing certain foods from children’s diets accounts for the difference in BMI percentiles.

Researchers at the University of North Carolina studied medical data of children who visited outpatient facilities from infancy to 11 years between 2007 and 2011.

Of the nearly 5,000 children tracked, 245 had food allergies. Experts compared their BMI, height and weight to the non-allergic kids and children with growth impairing conditions like cystic fibrosis and other abnormalities connected impaired growth.

The results showed that the food-allergic children had lower percentages overall compared to the other groups. The number of food allergies each child had also impacted the results.

“Compared to those children in the sample who had one or two food allergies, those with more than two had lower percentiles for height and weight. It suggests that the number of food allergies is a factor,” said head researcher Dr. Brian Vickery, “A greater number of food allergies translates into a greater number of dietary restrictions.”

The findings create a dilemma for parents who have to closely monitor their child’s diet, eliminating the allergic triggers but also having to be concerned their kids are getting ample and proper nutrition.

Dr. Joel Klein, an allergy specialist at Advocate Condell Medical Center, Libertyville, Ill., and Advocate Lutheran General Hospital, Park Ridge, Ill., says he’s seen an increase, particularly in food allergies, in his practice. It’s different from the old days.

“Many middle-aged adults, like me, can’t recall any schoolmates with food allergies when we were growing up. Some children with a food allergy have no family history of it,” Dr. Klein says.

He says the reasons aren’t clear and need further study.

“There are many theories, mainly coming from a focus on peanut allergies,” he says. “One theory, known as the hygiene hypothesis, is that when parents try to prevent their children’s infections or over-treat an infection during the first two years of a child’s life, they prevent the immune system from developing certain processes that would not reject certain foods, like peanuts.”