Predictors of weight status following laparoscopic gastric bypass

UMMS Affiliation

Department of Medicine, Division of Preventive and Behavioral Medicine; Department of Surgery

Publication Date


Document Type



Adult; Age Factors; Aged; Female; Follow-Up Studies; *Gastric Bypass; Humans; *Laparoscopy; Length of Stay; Male; Middle Aged; Obesity, Morbid; Predictive Value of Tests; Sex Factors; Treatment Outcome; *Weight Loss


Behavioral Disciplines and Activities | Behavior and Behavior Mechanisms | Community Health and Preventive Medicine | Preventive Medicine


BACKGROUND: Weight loss after bariatric surgery varies and depends on many factors, such as time elapsed since surgery, baseline weight, and co-morbidities.

METHODS: We analyzed weight data from 494 patients who underwent laparoscopic Roux-en-Y gastric bypass (RYGBP) by one surgeon at an academic institution between June 1999 and December 2004. Linear regression was used to identify factors in predicting % excess weight loss (%EWL) at 1 year.

RESULTS: Mean patient age at time of surgery was 44 +/- 9.6 (SD), and the majority were female (83.8%). The baseline prevalence of co-morbidities included 24% for diabetes, 42% for hypertension, and 15% for hypercholesterolemia. Baseline BMI was 51.5 +/- 8.5 kg/m(2). Mean length of hospital stay was 3.8 +/- 4.6 days. Mortality rate was 0.6%. Follow-up weight data were available for 90% of patients at 6 months after RYGBP, 90% at 1 year, and 51% at 2 years. Mean %EWL at 1 year was 65 +/- 15.2%. The success rate (> or = 50 %EWL) at 1 year was 85%. Younger age and lower baseline weight predicted greater weight loss. Males lost more weight than females. Diabetes was associated with a lower %EWL. Depression did not significantly predict %EWL.

CONCLUSION: The study demonstrated a 65 %EWL and 85% success rate at 1 year in our bariatric surgery program. Our finding that most pre-surgery co-morbidities and depression did not predict weight loss may have implications for pre-surgery screening.

DOI of Published Version



Obes Surg. 2006 Sep;16(9):1227-31. Link to article on publisher's site

Journal/Book/Conference Title

Obesity surgery

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Link to article in PubMed

PubMed ID