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Virtual Population Obesity Prevention (VPOP) Labs: Computational, Multi-Scale Models for Obesity Solutions

Description & purpose of resource

VPOP logoThe VPOP (Virtual Populations for Obesity Prevention) project has involved developing various multi-scale computational simulation models to help decision makers address questions and issues related to obesity prevention and control.


As described in Nutrition Reviews and in Forbes, obesity is a multi-scale systems problem. The relevant scales are interconnected and include factors such as physiology, behavior, culture, social networks, environment, policy, and economics. Changing only parts of the system may have little effect—or, even worse, unintended consequences.


While the human brain can see single cause and single effect outcomes, unaided, it is difficult to understand the multi-scale factors and relationships with obesity. Multi-scale systems approaches, models, and tools that the VPOP project has developed designs and tests various obesity prevention measures, policies and interventions within the safety of a computer before trying them in real life, which can save considerable time, effort, and resources.


Here are some examples of questions that the VPOP project has used multi-scale modeling to answer and address: 

  • Can sugar-sweetened beverage (SSB) warning labels impact obesity prevalence? The VPOP project built virtual representations of Baltimore, Philadelphia, and San Francisco to help city officials determine the potential impact of introducing SSB warning labels. The results from the VPOP’s multi-scale simulation model show when SSB warning labels appeared in all store locations in the three cities and reduced the chances of someone purchasing a sugary drink by 8%, obesity prevalence went down overtime by 1.69% in Baltimore, 4.08% in San Francisco, and 2.17% in Philadelphia while overweight prevalence dropped by 1.39% in Baltimore, 3.1% in San Francisco, and 0.36% in Philadelphia. Full paper published in AJPM.
  • Can following the current formula-feeding and solid food recommendations result in infants who are overweight or have obesity? Since most of the available formula-feeding and solid food guidelines for infants vary significantly, the VPOP project was utilized to evaluate how this can affect infant weight gain. The National Institutes of Health (NIH) and media outlets covered the results, which call for more consistent guidelines across the board. Specifically, the findings indicate that following each of the formula-feeding guidelines in the study led to infants becoming overweight/with obesity by 6 months old. Findings also suggested that following each of the solid food guidelines in the study for just a few months would drive the average body mass index (BMI) for the infants into the overweight category. Full papers published in Pediatric Research and AJPM.
  • What is the impact of youth physical inactivity in the U.S. and what is the value of increasing physical activity among children to different degrees? VPOP has developed a multi-scale, national model to estimate the cost of youth physical inactivity. Results from the model showed even modest increases in youth’s physical activity levels could avert billions in healthcare and other costs. For example, if half of the youth in the U.S. aged 8-11 years old were physically active, VPOP’s multi-scale model results showed this would avert $8.1 billion in direct medical costs and $13.8 billion in productivity losses. Increasing to 75% would avert $16.6 billion and $23.6 billion, respectively. The findings sparked heavy media coverage in outlets including New York Times, USA Today, and Yahoo News. Leaders in the field continue to bring the VPOP project’s generated results to the table to show decision makers the substantial savings attributed to getting and keeping youth physically active. Full paper published in Health Affairs.
  • What is the value of programs to increase youth sports participation in different locations? The Aspen Institute’s Sports & Society Program worked with the VPOP project for its ProjectPlay State of Play Report. The VPOP’s multi-scale computational simulation models were utilized at local levels to generate numbers for East Harlem, New York and Southeast Michigan in order to better understand the impact of increasing youth sport participation. The projections are used to show stakeholders the benefits of more youth meeting the CDC’s physical activity guidelines. Results from the VPOP project showed if 50% of youth in East Harlem get and stay active into adulthood, $36.1 million in direct medical costs and $38.5 million in productivity losses would be averted. If 50% of youth in Southeast Michigan get and stay active into adulthood, the VPOP project’s results show this will avert $1.8 billion in direct medical costs and $1.9 billion in productivity losses.
  • What is the value of increasing physical activity in a pre-existing program? Girl Scouts of Central Maryland (GSCM) worked with the VPOP projectto better understand the impact of its original Fierce & Fit program and how changes to the sessions could result in even greater benefits. Based on the results from the VPOP projectGSCM decided to change its Fierce & Fit program sessions six-fold. Results showed that this updated version of the program could save $84,828 in lifetime direct medical costs and $81,365 in lifetime productivity losses. By doubling the length, frequency and increasing the amount of physical activity during its sessions six-fold, the program is expected to deliver cost savings nearly 2.5 times greater than the cost of implementing the program. Full paper published in Obesity.
  • Can crime have an impact on physical activity levels and obesity? The National Heart, Lung, and Blood Institute (NHLBI) wanted to better understand the impact crime has on African American women’s physical activity levels and obesity prevalence in Washington D.C. Results from the VPOP project showed that reducing crime so that more physical activity locations were safely accessible could help decrease the annual rise in obesity prevalence. For example, results from VPOP’s multi-scale computational model suggest that reducing crime in Washington D.C. so more physical activity locations were accessible (increasing from 10% to 50%) decreased the annual rise in obesity prevalence in African American women by 2.69%. Full paper published in Obesity.
  • What is the value of reducing an adult’s weight at different ages? The VPOP project built a multi-scale computational simulation model to represent the U.S. adult population to show the lifetime costs and health effects for an individual with obesity, overweight, and healthy weight statuses at ages 20 through 80. The results from the VPOP project show that a 20-year-old adult who goes from having obesity to being overweight would save an average of $17,655 in direct medical costs and productivity losses over their lifetime. If the same person were to go from having obesity to a healthy weight, the average savings would be $28,020. The expected average savings are even higher—$18,262 and $31,447, respectively—for a 40-year-old. Full paper published in Obesity.

For more information on VPOP multi-scale computer simulation models, email Bruce Y. Lee, MD, MBA at

Spatial scales
whole organism
Temporal scales
weeks to months
human lifetime
Has this resource been validated?
How has the resource been validated?

We have organized the model credibility as face validity, criterion validity and convergence and divergence validity.



Face Validity: Involves developing the model in close collaboration with stakeholders who have intimate knowledge of the system


Our team currently works with the Baltimore City Health Department, New York City health department, Laureus Sport for Good, Aspen Institute, National Heart Lung and Blood Institute, Girl Scouts of Central Maryland and the Philadelphia Health Department. We regularly discuss model development and results with each partner, to ensure the model is reflecting the system based on their on-the ground understanding of it.


Criterion Validity: Reproducing observed trends at multiple levels

Sample Factors

Sample Sources

Overweight and obesity prevalence


National Health And Nutrition Examination Survey (NHANES)


Youth Risk Behavior Surveillance System (YRBSS)


Parish State of Youth Sports and Physical Activity New Orleans Sport for Development Coalition 2015.


Rivera JÁ. Review Childhood and adolescent overweight and obesity in Latin America: a systematic review. THE LANCET Diabetes & Endocrinology. 2014;2:321-332.


Baltimore City: Demographics and Social Determinants of Health (2005-2009). In: Maryland Department of Health and Mental Hygiene.




Proportion of students purchasing unhealthy snacks




Lent MR, Vander Veur S, Mallya G, et al. Corner store purchases made by adults, adolescents and children: items, nutritional characteristics and amount spent. Public Health Nutr


Average distance students regularly walk to store


How far will people walk to facilities in their local neighbourhoods. AUSTRALIA: WALKING THE 21ST CENTURY, INTERNATIONAL CONFERENCE, 2001, PERTH, WESTERN AUSTRALIA, VOL 3; 2001.


Burke M, Brown A. Distances people walk for transport. Road & Transport Research: A Journal of Australian and New Zealand Research and Practice 2007;16(3):16


Average daily SSB consumption levels



Likelihood of individuals using health apps to meet physical activity recommendations

National Cancer Institute’s 2015 Health Information National Trends Survey – HINTS

Proportion of population exercising

Behavioral Risk Factor Surveillance System National Survey – BRFSS)


Parish State of Youth Sports and Physical Activity New Orleans Sport for Development Coalition 2015.


Time spent in PE class

Gharib H, Galavíz KI, Lee RE, et al. The Influence of Physical Education Lesson Context and Teacher Behaviour on Student Physical Activity in Mexico. 2015;2041:160-164




Convergence and Divergence Validity: Comparing with other models and calculations


We have adapted the metabolic model from Hall et al(1) and Rhamandad et al(2) and validated using the methods described below:


The Rahmandad model was validated extensively for infants and children using empirical energy requirements and expenditure, weight, fat mass and fat free mass, and basal metabolic rate data from sources including Butte(3), Torun(4), and Ellis, et al(5). Our team followed the same validation process upon implementing the metabolic model, validating our baseline scenario against the energy inputs and growth trajectories reported in Butte et al, before, and also after we made changes to the model.We also compared our results against data from the 2004-2014 National Health and Nutrition Examination Survey (NHANES) and the model-estimated weights were not statistically different from those reported in NHANES.


  1. Hall, K.D., et al., Quantifying the Dynamics of Childhood Growth and Obesity.Lancet Diabetes and Endocrinology 2013. 1(2): p. 97-105.
  2.  Rahmandad H. Human growth and body weight dynamics: an integrative systems model. PLoS ONE. 2014;9(12):e114609.
  3. Butte, N.F., et al., Body composition during the first 2 years of life: an updated reference.Pediatr Res, 2000. 47(5): p. 578-85.
  4. Torun, B., Energy requirements of children and adolescents.Public Health Nutrition, 2005. 8(7A): p. 968-993.
Can this resource be associated with other resources? (e.g.: modular models, linked tools and platforms)
Key publications (e.g. describing or using resource)

Ferguson, M.C., Morgan, M.J., O’Shea, K.J., Winch, L., Siegmund, S.S., Solano Gonzales, M., Randall, S., Hertenstein, D.L., Montague, V., Woodberry, A., Cassatt, T. and Lee, B.Y. (2020), Using Simulation Modeling to Guide the Design of the Girl Scouts Fierce & Fit Program. Obesity, 28: 1317-1324. 

Lee, B. Y., A. Adam, E. Zenkov, D. Hertenstein, M. C. Ferguson, P. I. Wang, M. S. Wong, P. Wedlock, S. Nyathi, J. Gittelsohn, S. Falah-Fini, S. M. Bartsch, L. J. Cheskin and S. T. Brown (2017). "Modeling the economic and health impact of increasing children's physical activity in the United States." Health Aff (Millwood) 36(5): 902-908.

Lee, B. Y., M. C. Ferguson, D. L. Hertenstein, A. Adam, E. Zenkov, P. I. Wang, M. S. Wong, J. Gittelsohn, Y. Mui and S. T. Brown (2017). "Simulating the Impact of Sugar-Sweetened Beverage Warning Labels in Three Cities." Am J Prev Med, 54(2) 197-204.

Powell‐Wiley, T.M., Wong, M.S., Adu‐Brimpong, J., Brown, S.T., Hertenstein, D.L., Zenkov, E., Ferguson, M.C., Thomas, S., Sampson, D., Ahuja, C., Rivers, J. and Lee, B.Y. (2017), Simulating the Impact of Crime on African American Women's Physical Activity and Obesity. Obesity, 25: 2149-2155. 

Ferguson, M. C., K. J. O'Shea, L. D. Hammer, D. L. Hertenstein, N. J. Schwartz, L. E. Winch, S. S. Siegmund and B. Y. Lee (2019). "The Impact of Following Solid Food Feeding Guides on BMI Among Infants: A Simulation Study." American Journal of Preventive Medicine 57(3): 355-364.

Ferguson, M. C., K. J. O’Shea, L. D. Hammer, D. L. Hertenstein, R. M. Syed, S. Nyathi, M. S. Gonzales, M. Domino, S. S. Siegmund, S. Randall, P. Wedlock, A. Adam and B. Y. Lee (2020). "Can following formula-feeding recommendations still result in infants who are overweight or have obesity?" Pediatric Research.

Bruce Y. Lee
PI contact information
Computational Modeling
multi-scale model
agent based modeling
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