Figure 1.
Causal Loop Diagram of Adult and Child Social Transmission of Obesity.
This figure shows a causal loop diagram that illustrates the elements of the system we used for our research to model and test hypotheses regarding child and adult social transmission of unhealthy behaviors causing overweight and obesity. Adult level elements are shown in green and child level elements are shown in pink. Each element in the system is included with arrows drawn between elements to indicate relationships where they exist. The arrows are labeled with plus signs if a positive relationship exists between the elements and minus sign if an inverse relationship exists. The diagram includes adult-to-adult, adult-to-child, and child-to-child social transmission elements with arrows indicating how each increases overweight and obese individuals in the population for each respective age group. The overweight and obese individuals for each age group are shown with arrows to indicate its positive relationship with social transmission and inverse relationship with normal weight individuals. Finally normal weight individuals in each age group have arrows indicating an inverse relationship to social transmission of overweight and obesity. Within the elements and arrows described, circular arrows with a capital “R” are shown in the center to indicate reinforcing feedback loops. Elements of intervention impact are also included with arrows and plus/minus signs indicating relationships. Treatment intervention impact for children and adults are shown with negative labeled arrows to overweight and obese children and adults actively engaging in weight loss behaviors. Prevention intervention impact for children and adult levels are shown with negatively labeled arrows to social transmission. Intervention impact lines are shown at different widths to indicate differences in relative magnitude of impact. The thickest lines are shown regarding adult-to-adult impact and child-to-child impacts. Lines of medium thickness are shown regarding adult-to-child impact. Finally the thinnest lines are shown regarding child to adult impact.
Figure 2.
Stock Flow Diagram of Adult and Child Social Transmission of Obesity.
This figure shows the stock flow diagram built in Vensim. Adult level influences are shown in green and child level influences in pink. The core model elements are shown in solid lines, and intervention variables are indicated in dotted lines. Stocks of normal weight, overweight and obese adults are shown in green and stocks of normal weight, overweight, and obese children are shown in pink. Variables are shown with arrows to the flow equation they are included in. For example, child-to-child and adult-to-child social transmission rates are included in the flow equation from normal weight children to overweight children stock. Intervention impact variables are also shown with arrows to the behavioral variable they impact. For example, the total child prevention intervention impact reduces the child-to-child and adult-to-child social transmission rates. Finally the adult intervention impact and child intervention impact factors are also indicated and arrows indicate the total intervention impact levels they influence.
Table 1.
Description of the Obesity Prevention and Treatment Intervention Alternatives.
Table 2.
3×2 Table of Defined Scenario Sets for Simulation Experiments.
Figure 3.
Two Way Sensitivity Analysis of Social Transmission Rates on Childhood Overweight and Obesity Prevalence at 10 years.
This figure shows the results of the two-way sensitivity analysis of adult-to-child and child-to-child social transmission rates. The graph presents a three dimensional depiction of the childhood overweight and obesity prevalence at 10 years for each combination of adult-to-child and child-to-child social transmission rates tested. The chart indicates that the lowest childhood overweight and obesity prevalence is realized when both adult-to-child and child-to-child social transmission are at their lowest levels in each range. The change in overweight and obesity prevalence is greater across the adult-to-child than the child-to-child social transmission rate axis indicating slightly more sensitivity to the adult-to-child social transmission rate.
Figure 4.
Alternatives Impact on Childhood Overweight and Obesity Prevalence from Scenarios 1 and 4.
This figure shows the charts for each alternative from Scenario 1 and 4 influence on childhood overweight and obesity prevalence. The time frame charted is from 248 to 520 weeks. All alternatives are labeled and indicate that the ranking did not change between Scenario 1 or 4, nor was prevalence of each alternative greatly affected. The final childhood overweight and obesity prevalence ranges from approximately 53% with the intervention that included all intervention types and levels to 66% for baseline (no intervention).
Figure 5.
Alternatives Impact on Childhood Overweight and Obesity Prevalence from Scenarios 2 and 5.
This figure shows the charts for each alternative from Scenario 2 and 5 influence on childhood overweight and obesity prevalence. The time frame charted is from 248 to 520 weeks. All alternatives are labeled and indicate that the ranking did not change between Scenario 2 or 5, nor was prevalence of each alternative greatly affected. The final childhood overweight and obesity prevalence ranges from approximately 51% with the intervention that included all intervention types and levels to 66% for baseline (no intervention).
Figure 6.
Alternatives Impact on Childhood Overweight and Obesity Prevalence from Scenarios 3 and 6.
This figure shows the charts for each alternative from Scenario 3 and 6 influence on childhood overweight and obesity prevalence. The time frame charted is from 248 to 520 weeks. All alternatives are labeled and indicate that the ranking did not change between Scenario 3 or 6, nor was prevalence of each alternative greatly affected. The final childhood overweight and obesity prevalence ranges from approximately 49% with the intervention that included all intervention types and levels to 66% for baseline (no intervention).
Table 3.
Ranking and Final Childhood Overweight and Obesity Prevalence for Scenarios 4–6.