When your baby is exclusively breast- or formula-fed, you know that he's getting enough of what he needs. What about once he starts solids? Do you need to start calculating how many grams of protein he's consuming every day? What about iron and calcium?

The short answer: don't worry too much. Most of a baby's nutrition in the first six or seven months will be coming from breastmilk or formula. Up through the first year, a little more than half of a baby's calories and other nutrition will still be in liquid form; solid food will make up about half of a baby's calories. The purposes of solid foods during the first year are to help your baby get used to the texture of solid food, enhance his hand-eye coordination as he learns to get food into his mouth, and provide him with calories and vitamins (iron, etc.). Continue breast- or formula-feeding as necessary, and let your baby's appetite dictate his feeding schedule.

Nutrition Requirements:

Up to 6 months: 35–55 kcal/pound (a 15-lb baby would require 525–800 calories a day)

0–6 months 49 kcal/pound (about 650 calories a day)

6–12 months 45 kcal/pound (about 850 calories a day)

1–3 years 46 kcal/pound (about 1,300 calories a day)