my son is 3 years old. his weight is 10kgs he is not gaining the weight but he is active

A. dear mum the weight for age of your son is on the lower side consult doctor for nutritional deficiencies deworming twice a year give small frequent meals add ghee to every meal good protein from egg , non veg, sprouts, chana sattu, pulses, beans powdered nuts to food, dry fruits , paneer include seasonal fruits and vegetables in daily diet