Pay attention to foods that might bother your baby. If you notice a pattern, avoid the food for a few days and then reintroduce it to see what happens. Most mothers who eat a balanced diet and don't have a history of allergies won't need to restrict the foods they eat, except for a few things. Caffeine and alcohol can get into your milk, so limit their intake. You should also avoid certain kinds of fish and shellfish high in mercury; these include shark, swordfish, king mackerel and tilefish. You can safely eat up to 12 ounces (two servings) a week of fish and shellfish low in mercury, including shrimp, canned light tuna, salmon, pollock, clams, haddock, trout and catfish. Some medications may be harmful to your baby if they pass into your milk. Be sure to check with your health care provider about which foods, beverages and medications are safe for you and your baby. It is safe to eat peanuts and other allergenic foods while breastfeeding. Current research shows that consuming peanuts and other allergenic foods while breastfeeding may actually protect infants from developing allergies to those foods.