The purpose of this study was to develop a mathematical model to describe weight loss trend over time and to determine differences, if any, among various weight loss trends. Weight change was studied following Roux-en-Y gastric bypass (RGB) and vertical banded gastroplasty (VBG). The total number of patients analysed was 3172, 63.5% VBG and 36.5% RGB. Median age (years) for VBG was 36 (range 18-70) and RGB 38 (range 18-66). Median operative body mass index (BMI) (kg/m2) for VBG was 45.0 (range 30.1-90.5) and RGB 43.3 (range 30.4-80.6). Females represented 87% of the VBG patients and 89% of RGB patients. Obesity category percentages for each operative type were: super--VBG 20%, RGB 14%; morbid--VBG 78%, RGB 80%; obese--VBG 2%, RGB 6%. The development of a mathematical model to study weight loss over time was a two-stage process. First, weight loss trend was determined as evidenced by individual patient BMI values plotted over time. It was observed that plots represented quadratic curves, so the model BMI = B0 + B1(time) + B2(time)2 was used. Second, the estimated beta's (B0, B1, B2) were treated as response variables to estimate weight loss trend for the combination effect of three independent variables: gender (male and female), obesity category (super, morbid, obese) and operative type (VBG and RGB). It was found that the three independent variables simultaneously interact with patient weight loss (p = 0.0001).
This is a preview of subscription content, access via your institution.
Buy single article
Instant access to the full article PDF.
Price includes VAT (USA)
Tax calculation will be finalised during checkout.
About this article
Cite this article
Jiang, D., Renquist, K.E., Mason, E.E. et al. Weight Loss Curve Analysis. OBES SURG 1, 373–380 (1991). https://doi.org/10.1381/096089291765560755
- Body mass index
- obesity surgery
- weight loss