Understanding the dynamics of the obesity transition associated with physical activity, sedentary lifestyle, and consumption of ultra-processed foods in Colombia.

OBJECTIVE: We investigate the obesity transition at the country- and regional-levels, by age, gender, and socioeconomic status (SES) and its relationship to three health behavior attributes, including physical activity (PA), sedentary activities (ST), and consumption of ultra-processed foods (CUPF) within the urban population of Colombia, from 20,010 to 2050. METHODS: The study is informed by cross-sectional data from ENSIN survey. We used these data to develop a system dynamics model that simulates the dynamics of obesity by body mass index (BMI) categories, gender, and SES. This model also uses a conservative co-flow structure for three health-related behaviors (PA, ST, and CUPF). RESULTS: At the national level, our results indicate that the burden of obesity is shifting towards populations with lower SES as the gross domestic product (GDP) increases, particularly women aged 20-59 years with lower SES. Among this group of women, the highest burden of obesity is among those who do not meet the PA, ST and CUPF recommendations. At the regional level, our findings suggest that the regions are at different stages in the obesity transition. CONCLUSIONS: The burden of obesity is shifting towards women with lower SES as GDP increases at the national level and across several regions. This obesity transition is paralleled by a high prevalence of women from low SES groups who do not meet the minimum recommendations for PA, CUPF, and ST. Our findings can be used by decision-makers to inform age- and SES- specific policies seeking to tackle the obesity.

Using a system dynamics model to study the obesity transition by socioeconomic status in Colombia at the country, regional and department levels.

OBJECTIVE: We study the obesity transition by socioeconomic status (SES), gender and age within the Colombian urban population at the country, regional and department levels. DESIGN: The study is informed by cross-sectional data from the 2005 and 2010 ENSIN survey. We used these data to develop a system dynamics model that simulates the dynamics of obesity by body mass index (BMI) categories, gender and SES at the country, regional and department levels from 2005 to 2030. PARTICIPANTS: The sample size of the 2005 ENSIN comprised 8515 children younger than 5 years, 32 009 children and adolescents aged 5-17 years and 48 056 adults aged 18-64 years. In 2010, the corresponding numbers were 11 368, 32 524 and 64 425, respectively. PRIMARY AND SECONDARY OUTCOME MEASURE: The obesity prevalence ratio and prevalence rates for each BMI category. RESULTS: The results show, at the country level, transitions from overweight to obesity were projected to increase sharply among lower SES adults, particularly among women, suggesting that these groups will undergo an obesity transition by 2030. The model projections also indicate that the regions of Colombia are in different stages of the obesity transition. In the case of women, five out of the six regions were expected to undergo an obesity transition by SES over time. For men, only one region was expected to undergo an obesity transition. However, at the department level, trends in the burden of obesity varied. CONCLUSIONS: We evidence that the Colombian population could be experiencing an obesity transition where the increase in the GDP could be related to shifts in the burden of obesity from higher to lower SES, especially in women. These patterns support the need for policy planning that considers SES and gender, at the national and subnational levels, as important determinants of overweight and obesity among adults in Colombia.

Benchmarking seeding strategies for spreading processes in social networks: an interplay between influencers, topologies and sizes.

The explosion of network science has permitted an understanding of how the structure of social networks affects the dynamics of social contagion. In community-based interventions with spill-over effects, identifying influential spreaders may be harnessed to increase the spreading efficiency of social contagion, in terms of time needed to spread all the largest connected component of the network. Several strategies have been proved to be efficient using only data and simulation-based models in specific network topologies without a consensus of an overall result. Hence, the purpose of this paper is to benchmark the spreading efficiency of seeding strategies related to network structural properties and sizes. We simulate spreading processes on empirical and simulated social networks within a wide range of densities, clustering coefficients, and sizes. We also propose three new decentralized seeding strategies that are structurally different from well-known strategies: community hubs, ambassadors, and random hubs. We observe that the efficiency ranking of strategies varies with the network structure. In general, for sparse networks with community structure, decentralized influencers are suitable for increasing the spreading efficiency. By contrast, when the networks are denser, centralized influencers outperform. These results provide a framework for selecting efficient strategies according to different contexts in which social networks emerge.

Modeling interacting city traffic with finite acceleration and braking capacities.

Understanding the fundamental interactions in the complex behavior of one car moving in a sequence of traffic lights necessarily implies the inclusion of finite braking and accelerating capabilities. This characteristic is usually not considered in the standard cellular automaton models, where car interactions are the main concern. Therefore, here we develop a model which includes interactions and finite braking and accelerating capabilities, filling the gap between a standard cellular automaton model that considers car interactions but infinite braking and accelerating capabilities and the continuous one car model that includes finite braking and accelerating capabilities but does not consider, as the name indicates, car interactions. The proposed new model bridge these two seemingly different approaches in an effort to investigate how the traffic jams are produced. We found that, in the appropriate limits, we can reproduce the complex behavior of the one car continuous model and the dynamics close to the resonance induced by the interacting cars, forced by the traffic lights. In the processes of introducing car interactions, we observe how the average velocity decreases to finally obtain traffic jams, which are an emergent state in which the traffic lights control the generation of pulses of cars but do not control its average speed. This model is expected to improve our understanding of the complexity that appears in city traffic situations, as the finite braking and accelerating capabilities are necessary to describe the vehicle dynamics, the control strategy of traffic light synchronization, the motion of buses in segregated lights, and the whole urban design.

Towards a novel model for studying the nutritional stage dynamics of the Colombian population by age and socioeconomic status.

Low-and middle-income countries (LMICs) are experiencing a nutritional transition in which the burden of obesity tends to shift towards the lower-socioeconomic status (SES) group. We propose a system dynamics (SD) model for assessing the nutritional stage dynamics of the Colombian urban population by age and SES projected to 2030. This SD model captures the ageing population according to body mass index (BMI) categories and SES. In this model, the transference rates (TRs) between BMI categories by age and SES are estimated using a heuristic based on data obtained from national surveys. The simulation results show that the Colombian population, particularly those aged 20 to 39 years with a lower SES, is moving towards the overweight and obese categories. The TRs for overweight and obese categories in the lower SES group (the mean TR from not overweight to overweight = 0.0215 (per year) and mean TR from overweight to obese = 0.0098 (per year)) are increasing more rapidly than the those in the middle (the mean TR from not overweight to overweight = 0.0162 (per year) and mean TR from overweight to obese = 0.0065 (per year)) and higher SES groups (the mean TR from not overweight to overweight = 0.0166 and mean TR from overweight to obese = 0.0054 (per year)). Additionally, from 2005 to 2010, individuals aged 20 to 39 years had the highest TRs towards the overweight and obese categories (from 0.026 to 0.036 per year and from 0.0064 to 0.012 per year, respectively). The TRs also indicated that children aged 0 to 14 years are moving from the obese to overweight and from the overweight to not overweight categories. These TRs show that the Colombian population is experiencing an SES-related nutritional transition that is affecting the lower SES population. The proposed model could be implemented to assess the nutritional transitions experienced in other LMICs.

Network analysis of Bogotá's Ciclovía Recreativa, a self-organized multisectorial community program to promote physical activity in a middle-income country.

PURPOSE: Conduct a social network analysis of the health and non-health related organizations that participate in Bogotá's Ciclovía Recreativa (Ciclovía). DESIGN: Cross-sectional study. SETTING: Ciclovía is a multisectoral community-based mass program in which streets are temporarily closed to motorized transport, allowing exclusive access to individuals for leisure activities and physical activity. SUBJECTS: Twenty-five organizations that participate in the Ciclovía. MEASURES: Seven variables were examined by using network analytic methods: relationship, link attributes (integration, contact, and importance), and node attributes (leadership, years in the program, and the sector of the organization). ANALYSIS: The network analytic methods were based on a visual descriptive analysis and an exponential random graph model. RESULTS: Analysis shows that the most central organizations in the network were outside of the Health sector and include Sports and Recreation, Government, and Security sectors. The organizations work in clusters formed by organizations of different sectors. Organization importance and structural predictors were positively related to integration, while the number of years working with Ciclovía was negatively associated with integration. CONCLUSION: Ciclovía is a network whose structure emerged as a self-organized complex system. Ciclovía of Bogotá is an example of a program with public health potential formed by organizations of multiple sectors with Sports and Recreation as the most central.

Family and socio-demographic risk factors for psychopathy among prison inmates

A field study was conducted with prison inmates to explore to what extent family and socio-demographic characteristics represent risk factors for psychopathy and delinquent behavior. A psychopathy scale derived from Hare’s Revised Psychopathy Checklist and an instrument containing questions related to family and socio-demographic characteristics were administered to 178 prison inmates. The psychopathy scale’s reliability (alpha = .92) and construct validity were established. A confirmatory factor analysis provided support for a model showing a negative association between psychopathy and age at which the person stopped living with his family of origin, age of first incarceration, severity of delinquent acts, length of prison sentence, and length of time spent in prison. (X2/df = 1.40, FD = 1.34, PNI = 0.38, RMSEA =.04, IFI = .94, CFI = .94 and TLI = .93). Furthermore, the model sustained a positive association of psychopathy with income and frequency of incarceration. Level of education and age were eliminated from the model given that no significant associations were found among these variables and psychopathy. The validation of this model enables to interpret research findings in relation with attachment theory(AU)

Se realizó un estudio de campo con un grupo de prisioneros para investigar en qué medida las características familiares, sociales y demográficas de éstos representan factores de riesgo para la psicopatía y la delincuencia. Se administró a 178 internos en prisión una escala para medir la psicopatía derivada de la PCL-R de Hare junto con un instrumento creado ad hoc con preguntas relacionadas con sus características familiares, sociales y demográficas. Esta escala de psicopatía se mostró fiable (alpha = .92) y válida, validez de constructo. Un análisis factorial confirmatorio prestó a poyo a un modelo que sustenta una asociación negativa entre la psicopatía y la edad de abandonó del hogar de su familia de origen, la edad del primer internamiento en prisión, la gravedad del delito, la longitud de la sentencia y la cantidad de tiempo que estuvo internado en prisión (X2/gl = 1.40, FD = 1.34, PNCP = 0.38, RMSEA =.04, IFI = .94, CFI = .94 y TLI = .93). Por su parte, el modelo evidenció una asociación positiva entre la psicopatía, los ingresos económicos y la frecuencia de encarcelación. El nivel educativo y la edad fueron eliminados del modelo dado que no se encontraron asociaciones significativas entre estas variables. La validación de este modelo permite interpretar los hallazgos en relación con la teoría del apego(AU)