Baby's First Foods: What to Feed First and the 3-Day Rule
Begin with a soft, single-ingredient food that provides iron. Add other foods one at a time so a possible reaction is easier to identify.
SUMMARY
Start with single-ingredient foods, ideally something iron-rich such as iron-fortified infant cereal or puréed meat, then add mashed banana, sweet potato, or avocado. Introduce one new food at a time and wait 3 to 5 days before the next, so you can spot a reaction. Common allergens like peanut and egg can be introduced around 6 months, one at a time, unless your pediatrician says otherwise.
There is no single "correct" first food
Rice cereal was the traditional first food for decades. It is still fine, but it is not required. Current guidance from the AAP and CDC cares about three things: the food is a single ingredient, it is smooth enough to swallow, and it has no added salt or sugar. Any food that meets those three is a good first food.
One extra factor tips the choice: iron. A baby's iron stores from birth start to run low around 6 months, and breast milk alone is low in iron. That is why pediatricians suggest putting an iron-rich food early in the rotation, not necessarily first, but within the first couple of weeks.
Good first foods, and why
| Food | How to serve | Why it works |
|---|---|---|
| Iron-fortified infant cereal (oat, barley, multigrain, or rice) | Mix 1 teaspoon cereal with 4 to 5 teaspoons breast milk or formula. Thin, almost runny. | Easy iron. Familiar milk taste. |
| Puréed meat (chicken, beef) or lentils | Cook well, blend smooth with water or milk. | Iron that absorbs well, plus protein. |
| Mashed banana | Mash ripe banana with a fork. Thin with milk if needed. | Soft, no cooking, sweet enough on its own. |
| Sweet potato or carrot | Steam or bake, then purée. Freeze in ice-cube trays. | Mild, easy to batch, freezes well. |
| Avocado | Mash with a fork. | Healthy fat, no cooking. |
| Pear or apple | Cook until soft, then purée. | Gentle on the stomach. |
Vegetables first or fruit first? It does not matter much. The idea that fruit "spoils" a baby for vegetables is not supported by evidence. Offer both, and rotate.
The 3-day rule
Introduce one new food, then keep offering it for 3 to 5 days before adding the next new food. During that window, watch for:
- A rash, especially around the mouth or on the trunk
- Hives (raised, itchy welts)
- Vomiting or unusual diarrhea
- Swelling of the lips, face, or eyes
- Unusual fussiness or trouble breathing
Introduce one new food at a time, allowing 3 to 5 days before another to help identify possible reactions. Foods tolerated so far can be combined, but this does not guarantee that an allergy cannot develop later. Stop a suspected food and contact your pediatrician; breathing difficulty needs emergency help.
A food diary can help identify a suspected trigger, but symptoms alone do not confirm an allergy. Your clinician can advise how to introduce foods after a reaction.
Allergens: earlier than you might think
There is no evidence that delaying egg, dairy, soy, peanut, or fish beyond 4 to 6 months prevents food allergy. Introduce age-appropriate forms as solids begin around 6 months. Early peanut introduction has specific prevention evidence; severe eczema or egg allergy needs medical advice before peanut is offered.
- Peanut: smooth peanut butter thinned with warm water or mixed into cereal. Never whole peanuts or spoonfuls of thick peanut butter, which are choking hazards.
- Egg: well cooked, mashed or blended into purée.
- Dairy: plain whole-milk yogurt or cheese is fine after solids begin. Cow's milk as a drink still waits until 12 months.
Introduce allergens one at a time, on the 3-day rule, and offer them at home during the day when you can watch. If your baby has severe eczema or a known egg allergy, talk to your pediatrician before the first taste. They may recommend testing or want the first exposure to happen in the office.
A sample two-week rotation
| Days | New food | Also offer |
|---|---|---|
| 1 to 3 | Iron-fortified oat cereal | — |
| 4 to 6 | Sweet potato | Cereal |
| 7 to 9 | Banana | Cereal, sweet potato |
| 10 to 12 | Puréed chicken or lentils | Any cleared food |
| 13 to 15 | Thinned peanut butter in cereal | Any cleared food |
If a reaction occurs, note the food, time, and symptoms to tell your pediatrician.
When to call your pediatrician
Breathing difficulty, swelling of the tongue or throat, or sudden collapse after food needs emergency help immediately. Stop the food and seek prompt medical advice for hives, lip or face swelling, or repeated vomiting. Discuss persistent severe gagging, refusal of solids, or growth concerns with your pediatrician.
Frequently asked questions
Do I have to start with rice cereal?
No. Any iron-fortified infant cereal or iron-rich purée works. Many pediatricians now suggest rotating grains instead of relying on rice alone.
Can I mix two cleared foods together?
Yes, foods already tolerated can be combined. Introduce new ingredients separately so possible reactions are easier to trace; prior tolerance does not guarantee lifelong freedom from allergy.
Homemade or store-bought purée?
Either. Store-bought is convenient and safe. Homemade is cheaper and lets you control texture. Check store labels for added salt or sugar.
Not sure your baby is ready yet? Check the four readiness signs. For the whole picture, read the first-month guide to starting solids.