My sister's baby who is 19months old is weighing only 8.5kgs.she is hesitating to eat. her birthweight is 3.5kgs.is there anyways to increase her appetite?

Yes, she is quite underweight. Chronic illness is the most common cause of poor appetite and malnutrition. Your niece should be thoroughly examined by a pediatrician if possible. In the meantime, keep feeding her what she likes the most.

Once the baby has been checked to make sure there are no other causes for poor weight gain , you could work on increasing her protein and caloric intake with full fat dairy products , peanut butter , avocado, milk pudding . banana.eggs . Provide 6 to 8 smaller varied meals a day , avoiding excess beverages like juices .A vitamin supplement is usually recommended .Make mealtimes relaxed .