Effectiveness of intensive perioperative nutrition therapy among adults undergoing gastrointestinal and oncological surgery in a public hospital: study protocol for a pragmatic ran... by Abdul A’zim, A’ishah Zafrah, Abu Zaid, Zalina, Mohd Yusof, Barakatun Nisak, Jabar, Mohd Faisal, Mohd Shahar, Aainaa Syarfa