A study published in the April issue of the academy's journal, Pediatrics, found that 40 per cent of mothers are introducing solid food into their child's diet before the age of four months.
Sidney Harper, a nurse with the Fraser Health Authority's Baby Friendly Initiative, says feeding solid foods to a baby too young can set him or her up for a lifetime of allergies or asthma and even food sensitivities.
"The earlier solids are introduced, the more harmful it may be to the child," she said.
"Babies have rather porous guts, so they've got holes in these guts where foreign proteins can get through, and that can set a child up for a lifetime of allergies, or asthma, atopic disease, eczema, et cetera."
Pediatric experts recommend introducing solid foods only after an infant is four to six months old.
"We always say that they become closed, those pores become closed, nearer to the six-month mark," Harper said.
The study “Prevalence and Reasons for Introducing Infants Early to Solid Foods: Variations by Milk Feeding Type” looked at weekly feeding habits as reported by 1,334 U.S. mothers.
Mothers who had been feeding their child formula were twice as likely to begin solid foods too soon, as compared to mothers who were giving breast milk only.
The study also noted that the mothers who introduced solid foods to their babies before it was recommended tended to be younger, unmarried, with a lowel level of education, or were registered in a low-income nutrition support program.