Nicosia, Nancy and Ashlesha Datar. Neighborhood Environments and Physical Activity: A Longitudinal Study of Adolescents in a Natural Experiment. American Journal of Preventive Medicine (Forthcoming).

Datar A, Nicosia N. Assessing Social Contagion in Body Mass Index, Overweight, and Obesity Using a Natural Experiement. JAMA Pediatrics. 2018; 172(3):239-246. 

Summary: This study aims to determine whether exposure to communities with higher rates of obesity increases the body mass index (BMI) of individuals and their risk of being overweight or obese. Also, whether social contagion, shared environments, or self-selection can account for these identified differences. Using data collected by the Military Teenagers’ Environments, Exercise, and Nutrition Study, families from 38 military installations around the United States were examined to determine if individuals had higher BMI and greater odds of overweight and obesity when assigned to installations in counties with higher rates of obesity. Study participants included 1 parent and 1 child aged 12 or 13 years from 1519 families of Army-enlisted personnel. We conclude that exposure to counties with higher rates of obesity was associated with higher BMI and higher odds of overweight and/or obesity in both parents and children, and this may suggest the presence of social contagion. 

Nicosia N, Datar A. The Effect of State Competitive Food and Beverage Regulations on Childhood Overweight and Obesity. Journal of Adolescent Health. May 2017; 60(5):520-527. 

Summary: Policy efforts for combating childhood obesity have sought stronger state policies for regulating competitive foods and beverages (CF&Bs) available in schools. However, the evidence linking state policies to children’s overall diet and body weight outcomes is limited and mixed, and experts have called for more rigorous studies that are able to address concerns about selection bias. The present study leverages a rare natural experiment where children in military families are “assigned” to different state policies, due to their military parent’s periodic relocation, to examine whether state CF&B policies were associated with children’s body mass index (BMI) and overweight or obesity. We analyzed data from 894 12- and 13- year old children in army families and found that, compared to no policy, having strong or weak state policies was significantly associated with lower BMI, lower odds of overweight or obesity, and better dietary outcomes. Therefore, we conclude that multiple strong CF&B policies is likely needed to observe any meaningful changes in BMI and obesity. 

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Ghosh-Dastidar B, Haas A, Nicosia N, Datar A. Accuracy of BMI Correction Using Multiple Reports in Children. BMC Obesity. 2016; 3(37). 

Summary: Body mass index (BMI) has become the most common indicator to assess obesity, and while objective measurements are more accurate than self- or proxy-reports of BMI, they are sometimes infeasible. This study examines the accuracy of using multiple reports of BMI using reported height and weight from children’s self-reports and their parents’ reports. We conclude that using multiple reports of height and weight and BMI correction models maybe a cost-effective and practical solution to the bias of self-reported BMI measurements. 

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Nicosia N, Wong E, Shier V, Massachi S, Datar A. Parent Deployment, Adolescents' Academic and Social-Behavioral Adjustment, and Parent's Psychological Well-Being in Military Families. Public Health Reports. 2015.

Summary: Increases in the frequency and length of military deployments have raised concerns about the well-being of military families. We examined the relationship between a military parent’s deployment and (1) adolescent academic and social behavioral maladjustment and (2) parental psychological well-being. Using data from April 2013 to January 2014 and 1021 US Army families with children aged 12 or 13, we found that long deployments (>180 days in the past 3 years) were associated with adolescents’ academic and social-behavioral maladjustments and diminished parental well-being, especially among boys and military fathers. 

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Shier V, Nicosia N, Datar A. Neighborhood and home food environment and children's diet and obesity: Evidence from military personnel's installation assignment. Soc Sci Med. 2015. 

Summary: Research and policy initiatives are increasingly focused on the role of neighborhood food environment in children's diet and obesity. However, existing evidence relies on observational data that is limited by neighborhood selection bias. The Military Teenagers' Environments, Exercise, and Nutrition Study (M- TEENS) leverages the quasi-random variation in neighborhood environment generated by military personnel's assignment to installations to examine whether neighborhood food environments are associated with children's dietary behaviors and BMI. Our results suggest that neither the actual nor the perceived availability of particular food outlets in the neighborhood is associated with children's diet or BMI. However, the healthiness of food available at home was associated with healthy dietary behaviors while eating at fast food outlets and restaurants were associated with unhealthy dietary behaviors in children. Further, parental supervision, including limits on snack foods and meals eaten as a family, was associated with dietary behaviors. These findings suggest that focusing only on the neighborhood food environment may ignore important factors that influence children's outcomes. 

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Datar A, Nicosia N, Wong E, Shier V. Neighborhood Environment and Children’s Physical Activity and Body Mass Index: Evidence from Military Personnel Installation Assignments. Childhood Obesity. April 2015; 11(2):130-138. 

Summary: Obesity has become an epidemic in the United States, and this study aims to examine how a neighborhood environment influences an individual’s level of physical activity and subsequently their BMI. The natural experiment utilizes military families’ periodic relocation as a way to examine how different neighborhood environments could affect physical activity and BMI. Using data collected from 903 12- and 13-year old children in military families, we found that different features of the neighborhood environment were significant for off- versus on-post families, and conclude that efforts to increase children’s physical activity in military families should take into account the different neighborhood environment aspects that matter for children living on- versus off-post.