Accessibility to fast food restaurants linked to higher obesity prevalence

Greater access to fast food restaurants appears to increase the rates of neighbourhood obesity, while accessibility to green space areas is associated with reduced rates, a study has shown.

“This statewide study demonstrates that the spatial distribution of obesity was not random and possibly related to the effect of environmental factors, such as accessibility to fast food restaurants and green space areas in the built environment,” the researchers said.

Geocoded body mass index values were obtained from 20,927 individuals who visited the largest statewide health care network in Rhode Island. The association of obesity at the individual level, as well as obesity hot and cold spots, with the accessibility to fast food restaurants and green space areas was assessed using spatial analysis and logistic regression.

Obesity prevalence was 33 percent when adjusted by age. Most obese individuals live in neighbourhoods with medium or high accessibility to fast food restaurants (odds ratio [OR], 1.22, 95 percent confidence interval [CI], 0.81–0.97; OR, 1.20, 95 percent CI, 1.10–1.32, respectively). [Am J Med 2020;doi:10.1016/j.amjmed.2019.08.024]

In addition, obese people were less likely to live in neighbourhoods with the highest accessibility to green space areas (OR, 0.89, 95 percent CI, 081–0.97) compared with those with low accessibility.

Analysis of obesity clustering revealed that hot spots were 18 percent (OR, 0.82, 95 percent CI, 0.76–0.88) and 21 percent (OR, 0.79, 95 percent CI, 0.71–0.86) less likely to be in neighbourhoods with medium and high accessibility to green space areas, respectively.

On the other hand, hot spots were 1.65 (OR, 1.65, 95 percent CI, 1.53–1.77) and 4.81 times (OR, 4.81, 95 percent CI, 4.39–5.27) more likely to be in neighbourhoods with medium and high accessibility to fast food restaurants.

While the association between access to fast food restaurants and obesity has been studied previously, the results were inconclusive. Most analyses showed a possible positive relationship between high access to fast food restaurants and obesity. [Obes Rev 2011;12:e460-e471; Obes Rev 2008;9:535-547]

Previous studies have also reported an association between accessibility to green spaces and obesity, but the results were mixed and inconsistent. [Obes Rev 2011;12:e183-e189; J Public Health (Oxf) 2011;33:212-222]

“Although not establishing a causal relationship, our results add to a growing body of evidence that these environmental factors affect the health of a neighbourhood,” the researchers said.

Efforts at changing eating and exercising have been shown to be beneficial only in the beginning, with the effect waning over time. Policy-level interventions are often recommended to eliminate the “obesogenic environment disparities,” according to the researchers. [CMAJ 2014;186:1275; Health Place 2009;15:364-373]

“These disparities are highlighted in our study, which suggests that obesity cold spots are more likely to be located in neighbourhoods with high accessibility to green spaces and lower accessibility to fast food restaurants,” they said.

“In this regard, interventional studies aiming to measure the potential health benefits of regulating fast food availability and redesigning the built environment with the addition of green space areas are needed to provide additional evidence,” the researchers noted. [Ann Behav Med 2012;44:248-258; Cad Saude Publica 2013;29:1988-1996; Obes Rev 2011;12:e183-e189]