The good news is that your baby is the single best authority for when he needs to be fed and when he is satisfied. His internal regulator for hunger and fullness is fine-tuned to his particular energy needs. That’s why rigidly counting the ounces of formula or the number of minutes per breast-feeding session isn’t the best way to calculate how much is enough. Instead, pay attention to his cues; his behavior will tell you when he’s hungry and when he’s full.
Research shows that when caregivers are responsive to feeding cues, infants will regulate their own energy intake. But when babies’ cues aren’t heeded, they’re more likely to become confused about their sensations of hunger and fullness, possibly leading to preferences for less healthful (high-fat, high-calorie) foods and a greater risk for childhood obesity.
Sucking on his fist, smacking his lips. If you feed a breast-fed baby when you see these signs, rather than waiting, he’ll latch on more easily.
Rooting. During your baby’s first weeks, when you stroke his cheek, his natural reflex will be to turn toward the bottle or breast and make sucking motions with his mouth. After 4 months of age, rooting becomes a voluntary action rather than a reflex.
Opening his mouth while feeding. Translation: “More, please!” A hungry baby may continue to show interest in sucking even after finishing the first breast or bottle.
Smiling during feeding. Babies older than 4 months will show their interest in continuing to eat by looking at you and smiling as they feed.