Preoperative 4-week low-calorie diet reduces liver volume and intrahepatic fat, and facilitates laparoscopic gastric bypass in morbidly obese

Obes Surg. 2011 Mar;21(3):345-50. doi: 10.1007/s11695-010-0337-2.


Background: The aim of this study was to explore changes in liver volume and intrahepatic fat in morbidly obese patients during 4 weeks of low-calorie diet (LCD) before surgery and to investigate if these changes would facilitate the following laparoscopic gastric bypass.

Methods: Fifteen female patients (121.3 kg, BMI 42.9) were treated preoperatively in an open study with LCD (800-1,100 kcal/day) during 4 weeks. Liver volume and fat content were assessed by magnetic resonance imaging and spectroscopy before and after the LCD treatment.

Results: Liver appearance and the complexity of the surgery were scored at the operation. Eighteen control patients (114.4 kg, BMI 40.8), without LCD were scored similarly. Average weight loss in the LCD group was 7.5 kg, giving a mean weight of 113.9 kg at surgery. Liver volume decreased by 12% (p < 0.001) and intrahepatic fat by 40% (p < 0.001). According to the preoperative scoring, the size of the left liver lobe, sharpness of the liver edge, and exposure of the hiatal region were improved in the LCD group compared to the controls (all p < 0.05).

Conclusions: The overall complexity of the surgery was perceived lower in the LCD group (p < 0.05), due to improved exposure and reduced psychological stress (both p < 0.05). Four weeks of preoperative LCD resulted in a significant decrease in liver volume and intrahepatic fat content, and facilitated the subsequent laparoscopic gastric bypass as scored by the surgeon.

MeSH terms

  • Adipose Tissue / chemistry
  • Adipose Tissue / pathology*
  • Adult
  • Body Weight
  • Caloric Restriction*
  • Female
  • Gastric Bypass / methods*
  • Humans
  • Laparoscopy
  • Liver / pathology*
  • Magnetic Resonance Imaging
  • Obesity, Morbid / pathology*
  • Obesity, Morbid / surgery
  • Organ Size
  • Preoperative Care*