• Primary Outcome Measures: The mean time (hours) that reach to the caloric goal in every group (7 days after intervention) • Secondary Outcome Measures: The rate of onset Gastric residual (%) (baseline and first 7 days after intervention); Abdominal pressure mmHg; Level of plasma motilin (pg/ml); Rate of new onset pneumonia. This evidence concerns the gene MLN and susceptibility to pneumonia measurement.