Preoperative dietitian-led calorie-restricted diet: impact on left hepatic lobe volume and laparoscopic upper GIT surgery visibility

Background: The surgical benefits of preoperative low- or very low-calorie diets (LCDs or VLCDs) in bariatric surgery patients have been widely studied. This study aimed to observe the changes in body composition and left hepatic lobe volume (LHLV) following a two-week dietitian-led calorie-restricted diet in non-bariatric laparoscopic surgery patients, where fatty liver often complicates the surgery. Methods: The study included 47 patients scheduled for a hiatus hernia repair with an anti-reflux procedure. Participants underwent bioelectrical impedance measurements and abdominal ultrasounds to determine changes in LHLV at baseline and again pre-surgery after following a calorie-restricted diet (800–1000 kcal daily) for two weeks. Results: Participants (median baseline body mass index [BMI]: 33.4 (30.9–36.0) kg/m²) experienced statistically significant (p < 0.05) decreases in body mass, BMI, waist circumference, body fat mass, body fat percentage, abdominal fat and muscle mass on the two-week calorie-restricted diet. A median LHLV reduction of 33% (IQR 12.8–49.6%, p < 0.05) was noted. The outcomes of the ultrasound were unknown to the surgeons at the time of the surgery, and they subjectively reported good surgical visibility of the oesophagogastric (EG) junction in 86.5% of cases. Conclusion: The findings suggest that in obese patients, losing 2.2 kg of body fat and 2.5 cm in waist circumference on a two-week dietitian-led calorie-restricted diet may significantly reduce LHLV that could potentially improve surgical visibility. Further research should determine if these changes in body composition may be used as a proxy for liver sonar.