The average infant has about a 5 percent chance of developing food allergies by age 3; there's no evidence that restricting certain solid foods will help prevent allergies for most babies. Likewise, it's fine to continue eating your normal diet when you're pregnant or breastfeeding.
But if you or your baby's dad has asthma, hay fever, eczema, or food allergies, the risk goes up to 20 or 30 percent. If you both do, the risk is 40 to 70 percent. There's still debate whether restricting your diet when you're pregnant or breastfeeding—avoiding peanuts, for example—will reduce your baby's chances of developing allergies, so it's best to talk over your particular situation with your doctor. But if there's a family history, once your baby is born, follow these recommendations from the American Academy of Pediatrics:
1. Breastfeed exclusively for 6 months; if you use formula, buy a hypoallergenic one, such as Nutramigen, or Alimentum. (Even after he's eating, he'll still need breastmilk or formula until he's at least 1.)
2. After 6 months, introduce solids, but avoid the foods that cause most food allergies: peanuts, tree nuts, cow's milk, and shellfish. You may also want to skip wheat and soy.
3. After age 1, introduce whole cow's milk, wheat, and soy (if you've avoided them). Do so one food at a time, and wait a few days before introducing the next one so you can watch to see if there's any reaction.
4. Wait until your child's at least 2 before feeding him eggs, and at least 3 before giving him seafood or nut products.