Aim: This study investigates the effects of normal versus high-protein intake on malnutrition and anthropometric parameters in critically ill patients receiving enteral nutrition (EN) in the
intensive care unit (ICU).

Study Design: Conducted between July and October 2022, this study included 42 patients aged 19-64 years who were receiving EN support. Participants were divided into two groups: 21 patients in the normal-protein group (0.8-1.2 g/kg/day) and 21 patients in the high-protein group (>1.2 g/kg/day). Anthropometric measurements, including upper mid-arm circumference, calf circumference, knee height, body weight, and height, were taken on days 1, 3, 5, and 15.

Results: The average age of participants was 47.1±13.2 years. No significant differences were found between the groups in baseline characteristics (p>0.05). Protein intake was significantly higher in the high-protein group (p<0.05); however, there were no statistically significant differences between groups in changes in upper mid-arm circumference, Body Mass Index (BMI), or Nutritional Risk Screening 2002 (NRS-2002) scores (p>0.05). Within-group comparisons showed significant improvements in both NRS-2002 and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores over time (p<0.05). There were no significant differences in age, gender, marital status, weight, height, or BMI between the two groups (p>0.05). The average weight, height, and BMI across participants were 75.57±13.97 kg, 171.26±8.51 cm, and 25.72±4.26 kg/m², respectively. Protein intake on Day 1 (90.36±9.2 g) and Day 15 (90.36±9.2 g) in the high-protein group was significantly higher than in the normal-protein group (p<0.05). No significant differences were found between groups in terms of knee height, upper mid-arm circumference, or reference percentile values (p>0.05).

Conclusions: This study found no significant relationship between protein intake and upper mid-arm circumference, BMI, or NRS-2002 scores. Further research with a larger sample size
and longer follow-up period is needed to confirm these findings.