Individual eating behavior is often linked to environmental influences, such as the density of fast food restaurants. A study by Li, Harmer, Cardinal, Bosworth, & Johnson-Shelton (2009) aimed to explore and evaluate the correlation between obesity and fast food availability in the area. The researchers also focused on local community behavior, psychological traits, social traits, and demographics and explored their relationship with obesity.
The researchers included 120 neighborhoods in the study, and the sampling design was stratified to take in account the variables relevant to the research aims, including urban form, median household income, race, and ethnicity. The target population included adults between 50 and 75 years of age, and each potential participant was contacted through direct mail and a telephone contact later.
With a response rate of 48 percent, the researchers managed to include 1,221 participants into the study, so it seems they had the option to participate voluntarily. All participants who agreed to participate gave their written consent before the assessment took place, and their transportation costs were settled. The study took place in Portland, Oregon, and the research protocol received the Institutional Review Board approval from the Oregon Research Institute. The authors did not address any reasons that would suggest potential benefits and risks associated with the study, and there do not seem to be any risks or benefits associated with the study.
The research had a cross-sectional and multistage design. There were two types of measures taken. From the participants, the researchers took body-mass index (BMI), eating self-efficacy, fried food consumption, eating-out behavior, intake of fruits and vegetables, sociodemographic characteristics, and physical activity levels measures. Frequency of eating at fast food restaurants, eating self-efficacy, physical activity, fruit and vegetable intake, sociodemographic measures, and the amount of fried food consumed were independent variables.
In the neighborhood, the researchers measured the amount of fast food restaurants, residential density, the percentage of non-Hispanic black residents and Hispanic residents, median household income, and land use. Density of fast-food outlets, land use mix, and sociodemographics were identified as independent variables. The only dependent variable measured was the prevalence of obesity in the neighborhoods.
The data from participants was obtained through informative interviews, but fruit and vegetable consumption was assessed with the Fruit and Vegetable screener while physical activity was measured by the Behavioral Risk Factor Surveillance System Survey (BRFSS). Although the researchers did not provide reasoning for their choices directly, they referred the reader to relevant sources that supported the validity of the instruments used for collecting data. The data relevant to neighborhood measures were bought from inoUSA, generated from Portland’s Regional Land Information System databases, and taken from the 2000 census data.
Because of the multilevel design, the researchers created a multilevel random effects logistic model that defined neighborhood variables as level-2 units, in which residents were nested as level-1 units. Multilevel logistic regression analyses were used to identify the correlation between obesity and independent variables on both individual and neighborhood levels. To ensure the accuracy of the model used, the researchers conducted model testing with Hierarchical Linear and Nonlinear Modeling software.
However, the study shows several limitations because of the model and type of study used. First, the cross-sectional study design does not allow the researchers to make conclusions about the causality of obesity. Second, fast-food outlet density levels were measured only in the residents' neighborhoods instead of other environments in which they might work or spend a lot of time. Third, because some measures, such as frequency of eating at fast-food restaurants, were self-reported and cannot be considered completely reliable.
Despite the limitations, the researchers coherently present their conclusion because it is relevant to the study aim and methodological protocols used. According to Li et al. (2009), the results suggest that the density of fast-food outlets does increase obesity risks and is associated with unhealthy lifestyle of older adults. The findings can be considered reliable and accurate because they are consistent other studies.
For example, Casey et al. (2008) found that people in rural communities often ate at local fast food outlets, so they increased the risk for obesity and related health issues. According to a literature review by Story, Kaphingst, Robinson-O'Brien, and Glanz (2008), implementing positive physical activities and eating habits is difficult in environments that do not support making healthy choices. Pearce, Blakely, Witten, and Bartie (2007) also confirmed that a high density of fast food restaurants and low socioeconomic status contributed to obesity.
There are several implications for public health nurses because it can be used for developing land use policies and public health policies that will assist in creating a better eating environment instead of allowing an unregulated growth of fast food restaurants. The results also explain how lack of confidence, lack of physical activity, and other unhealthy habits are persistent in an unhealthy environment and impact the eating choices individuals make. With that in mind, public health interventions should be aimed at improving psychosocial conditions and physical activity among the populations because they are correlated with poor eating choices and may assist in creating better eating habits.
References
Casey, A. A., Elliott, M., Glanz, K., Haire-Joshu, D., Lovegreen, S. L., Saelens, B. E., Sallis, J. F., & Brownson, R. C. (2008). Impact of the food environment and physical activity environment on behaviors and weight status in rural U.S. communities. Preventive Medicine, 47(6), 600-604. doi:10.1016/j.ypmed.2008.10.001
Li, F., Harmer, P., Cardinal, B. J., Bosworth, M., & Johnson-Shelton, D. (2009). Obesity and the built environment: Does the density of neighborhood fast-food outlets matter? American Journal of Preventive Medicine, 23(3), 203-209.
Pearce, J., Blakely, T., Witten, K., & Bartie, P. (2007). Neighborhood deprivation and access to fast-food retailing: A national study. American Journal of Preventive Medicine, 32(5), 375-381. doi:10.1016/j.amepre.2007.01.009
Story, M., Kaphingst, K. M., Robinson-O'Brien, R., & Glanz, K. (2008). Creating healthy food and eating environments: Policy and environmental approaches. Annual Review of Public Health, 29, 253-272. doi:10.1146/annurev.publhealth.29.020907.090926
