There is no ideal weight for infants and children; however, instead the weight and height are based on ranges as per age and where the weight/height relates by percentiles. His weight is just below the 5th percentile for his age. Guideline for a 9-12 month old child should eat the following: Formula (6-8oz) 3-5 feedings a day, Dairy 1 serving a day – cheese (1/2 oz) or yogurt (1/2 cup). Starch 2 feedings a day – Infant Cereal (2-4 Tbsp), bread (1/2 slice), crackers (2), or pasta (3-4 Tbsp). Fruits or Vegetables 1-2 feedings a day – (3-4 Tbsp). Meat 2 feedings a day – 3-4 Tbsp) or beans (1/4 cup). This food should be feed 3 meals a day with snacks between the meals and at his age he can start with finger foods and he can feed himself with him fingers. Hoped this helped you.