Breastfeeding is usually recommended for five-month-old babies. If breastfeeding is not possible, it is necessary to supplement 800-1000ml of formula milk, but there are individual differences. For five-month-old babies, breastfeeding is generally recommended. For babies with insufficient breastmilk or those who cannot breastfeed adequately for special reasons, formula milk should be added because it cannot meet the baby’s growth and development needs. It is usually considered best to breastfeed at 5 months of age, feeding on demand and alternating between the two breasts. For mixed feeding babies with insufficient breastmilk, when weight gain is satisfactory, urine output is normal and the baby sleeps well, the amount of additional formula milk supplementation is usually considered appropriate. If breastfeeding is not possible and only formula milk is used for feeding, supplementation of about 800-1000ml per day is required, but there are individual differences. Consultation with a specialist for guidance on feeding is recommended.