 After feeding with olive oil infants will have received same amount of calorie with infants who will receive eoprotin-fortified breast milk. At the end of study, if participants identify that olive oil doesnt increase proinflammatory cytokines and provide enough weight gain in premature infants, investigators will suggest olive oil to replace eoprotin which is a very costly breast milk-fortifier. Investigators believe this situation will contribute to both country and family budgets. 