Food Allergy

Your child is more likely to have a food allergy if a parent, brother or sister has an allergy.

Food allergies are most common in infants and preschoolers. Many children will outgrow a food allergy, but some will have an allergy for life.

It is recommended that babies be exclusively breastfed (be fed only breast milk) for the first six months of life to lower risk of allergy. Breast milk helps a baby's immune system to mature and helps to protect the mucosa in the baby's gastro-intestinal tract.

Health Canada indicates that common food allergens that are a source of iron, such as fish and eggs, can be introduced after six months of age. Delaying the introduction of allergenic foods after six months of age is not currently recommended as a way to prevent food allergy.

How to introduce new food

Offer one new food to your child at a time and watch for signs of an allergic reaction. Some signs of food allergy include:

  • Rash
  • Vomiting
  • Diarrhea
  • Itchy or watery eyes
  • Swelling of the mouth or face
  • Breathing problems

If your child has a reaction to eating a food or if you think your child may have a food allergy, stop feeding that food and contact your health care provider. Your health care provider may want to refer your child to an allergist for testing.

When offering a new food that is a common food allergen such as egg, milk, mustard, peanut,* seafood (fish and shellfish), sesame, soy, sulphites, tree nuts* and wheat (including wheat-based infant cereal): 

  • Offer one at a time and wait two days before introducing another new food 
  • During the two day waiting period, watch for signs of food allergy (see above)
  • Once safely introduced, continue to offer the food regularly so they will keep tolerating it

*Nuts are a choking risk for babies and young children; do not offer whole nuts until after four years of age

It is important to get a proper diagnosis of a food allergy before permanently removing a food from your child's diet.

If your child is not able to eat certain foods due to allergy, you may want to talk to a Registered Dietitian to help you make sure your child gets all the nutrients they need.

If there is a history of food allergy or other kind of allergy in your family, you may want to talk to your health care provider about your child's situation.

Child care centres and schools

Child care centres and schools in Ontario are required by law to have a policy and procedures for handling children's allergies. If your child has a food allergy, talk to a supervisor, teacher or principal about their policy.

Frequently asked questions

Do pregnant or breastfeeding women need to avoid foods that the biological father is allergic to?

No. Pregnant and breastfeeding women do not need to avoid foods that their baby's father is allergic to.

Do I need to avoid any foods when I am pregnant to prevent my baby from becoming allergic?

If you have a food allergy you should avoid foods that you are allergic to. There is no evidence that avoiding other foods during your pregnancy will prevent food allergy in your child.

I am breastfeeding my baby - what foods should I avoid to prevent my baby from having a food allergy?

There is no evidence that avoiding foods when you are breastfeeding will prevent your child from having a food allergy. However, if your baby has sensitivity or allergy to a food, you will need to avoid eating that food.

Should I delay giving some foods to my child to prevent food allergy?

Regardless of family history of allergy, there is no evidence that delaying foods past six months of age prevents food allergy. Delaying foods or not offering certain foods may increase risk of nutritional deficiencies and inadequate energy intake. This includes foods considered to be highly allergenic such as: wheat, fish, shellfish, eggs /egg white, soy, milk products, peanut products** and tree nut products.**

If an infant shows signs of allergy, talk to your health care provider.
Delaying some foods may be recommended.

**Although nut products may be considered safe after six months of age in relation to allergy prevention, nuts are a choking hazard for young children. Foods that are hard, small and round, smooth and sticky are not considered safe for young children and should not be given to children under four years of age.

My child has an allergy to a food - what can I do?

There is no cure for a food allergy; it can only be managed. The following are some ways to deal with a food allergy:

  • Stop feeding the food and offer other foods to replace the nutrients in the food being removed
  • Watch your child for signs of an allergic reaction and know what to do if they have a reaction
  • Learn about your child's food allergy and how to deal with it
  • Always read the ingredient list on the food label carefully for the food(s) to be avoided. Food producers can change the ingredients in their foods without notice, so read the label every time you buy the food
  • If your child has medication for dealing with a severe allergic reaction, always have it close to your child. Let others looking after your child know when and how to use it
  • Talk to the supervisor, teacher or principal at your child's child care centre or school to let them know your child has a food allergy. In Ontario, they must have a policy and set of procedures for handling children's allergies

Where can I find information about food allergy?

  • These websites may help you learn more about food allergy and how to manage it:
  • The book Dealing with Food Allergies in Babies and Children by Janice Vickerstaff Joneja, PhD, RD; Bull Publishing Company, 2007 is available to borrow from the Public Health Resource Centre at 99 Regina St. South, 519-883-2256
  • Talk to a Registered Dietitian at EatRight Ontario about food substitutions when you need to remove a food from your child's diet. Call 1-877-510-5102 or go to to ask your question