Obesity Surgery

, Volume 22, Issue 4, pp 597–601

Lean and Fat Mass Loss in Obese Patients Before and After Roux-en-Y Gastric Bypass: A New Application for Ultrasound Technique


    • Department of Medicine, Division of EndocrinologyUNIFESP
  • J. S. Marchini
    • Department of Medicine, Division of Clinical NutritionUniversity of São Paulo
  • G. Carneiro
    • Department of Medicine, Division of EndocrinologyUNIFESP
  • C. H. Arasaki
    • Department of Surgery, Division of Gastroenterological SurgeryUNIFESP
  • M. T. Zanella
    • Department of Medicine, Division of EndocrinologyUNIFESP
Clinical Research

DOI: 10.1007/s11695-011-0538-3

Cite this article as:
Pereira, A.Z., Marchini, J.S., Carneiro, G. et al. OBES SURG (2012) 22: 597. doi:10.1007/s11695-011-0538-3



This study aims to evaluate the thickness of the femoral quadriceps and biceps brachii and brachialis muscles bilaterally and the adjacent subcutaneous fat in patients undergoing gastric bypass Roux-en-Y before and after surgery, using ultrasound as the diagnostic method of choice.


We studied 12 patients undergoing this surgical method preoperatively and during the first, third, and sixth postoperative months. During these periods, patients were evaluated by ultrasound to determine the thickness of subcutaneous adipose tissue and muscle of the upper and lower limbs.


Postoperatively, these patients showed a reduction in the thickness of the upper and lower extremities muscle and adipose tissue as compared to their preoperative values. There was a significant difference in the loss of muscle thickness in all postoperative months and in the thickness of fatty tissue in the sixth month after surgery, compared to the preoperative muscle and fatty tissue thickness.


Ultrasound can be considered as the diagnostic method of choice when assessment of the fat and lean body mass is required in morbidly obese patients before and after bariatric surgery.


Muscle ultrasoundFat massObesityUltrasoundLean massGastroplastyBariatric surgeryGastric bypass Roux-en-Y

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© Springer Science + Business Media, LLC 2011