A model for the dynamics of human weight cycling based on the work of Albert Goldbeter [J. Biosci, 31, 129-136] and presented by Lauren Shepherd as a final project for BIOEN 589, University of Washington.
Download Original paper by Albert Goldbeter
Download Commentary on model by Lauren Shepherd
Code: Download the JSim project file.
Key Terms: oscillations, rhythms, weight cycling, Publication
National Simulation Resource firstname.lastname@example.org
Changes from the original model:
The original model was changed by Lauren Shepherd to allow exploration of the effects of metabolic changes over time. The static parameter 'a' (metabolic efficiency) was turned into a linear function that slowly increases with time. To activate this part of the code, enter '2' as the value for the 'ab' parameter. Under these conditions, the oscillatory behavior still exists, but the maximum body weight continues to climb over time.
A second change can be made by altering the energy dissipation parameter 'b'. To activate this change, enter '3' as the value for the 'ab' parameter. A body weight decrease will be observed with this metabolic change.
The model provided here is a revised version of the model developed by Lauren Shepherd. As suggested by Shepherd, the model can now display weight directly, rather than in the scaled units used in the original model by Albert Goldbeter. Goldbeter's model has weight presented using a unit system that has a one unit increase in weight equal 25 kilograms for a moderately overweight person, and 75 kilograms for an obese person. When running this model, enter '1' as the 'ibw' value to signify a moderately overweight individual, and '2' for an obese individual.
Model development and archiving support at physiome.org provided by the following grants: NIH/NIBIB BE08407 Software Integration, JSim and SBW 6/1/09-5/31/13; NIH/NHLBI T15 HL88516-01 Modeling for Heart, Lung and Blood: From Cell to Organ, 4/1/07-3/31/11; NSF BES-0506477 Adaptive Multi-Scale Model Simulation, 8/15/05-7/31/08; NIH/NHLBI R01 HL073598 Core 3: 3D Imaging and Computer Modeling of the Respiratory Tract, 9/1/04-8/31/09; as well as prior support from NIH/NCRR P41 RR01243 Simulation Resource in Circulatory Mass Transport and Exchange, 12/1/1980-11/30/01 and NIH/NIBIB R01 EB001973 JSim: A Simulation Analysis Platform, 3/1/02-2/28/07.