Although research findings indicate that fast-food restaurants dominate the food landscape and the demand for fast food is increasing, there are few studies that have examined the association of spatial access to fast food on the frequency of consuming fast-food meals, especially among rural adults [19, 36]. This is critical considering relationships reported between frequency of fast-food meal consumption and increased caloric and fat intake and reduced intake of key nutrients [1, 10, 14, 18, 48, 49, 54, 55]. However, studies of fast-food consumption rarely have considered measured access to fast food as a contributing factor [1, 6, 10, 14, 17, 18, 33, 49, 56]. Findings from this study extend the understanding of the association of personal characteristics and access to fast food on frequency of fast-food meal consumption among adults who reside in rural areas. This is apparently the first study, to our knowledge, that: 1) uses ground-truthed data on access and availability of fast food from traditional and non-traditional fast-food outlets, such as convenience stores, supermarkets, and grocery stores and 2) provides a comprehensive picture of the fast-food environment for a large rural area. Our analyses revealed that both dimensions of spatial access - proximity and coverage - indicated significantly better access to fast food from non-traditional outlets than from traditional fast-food restaurants alone. A second important finding was that spatial access to fast food, in terms of proximity and coverage, was associated with frequency of fast-food meals especially among women. Several findings require further discussion.
Unlike studies that asked specifically about fast-food restaurant use from major national/international chains, our rural respondents were asked about weekly, general fast-food meal consumption [10, 13, 14, 17–19, 34, 47, 49–51, 56]. By not restricting the responses to major chains, respondents were able to consider the more prevalent local and regional fast-food restaurants as well as other fast-food venues found in rural areas. On the average 1.3 fast-food meals were consumed by the 1,409 rural adults in our sample. However, compared with other studies, the rural men and women in this sample consumed fewer fast-food meals than reported in predominately urban areas [17, 46].
Potential spatial access to fast-food
Compared with a previous study of rural areas in three states that measured access by self-reported walking time from residence to the nearest fast-food restaurant , this study used ground-truthed methods to identify, geocode, and calculate the network distance to the nearest traditional and non-traditional fast-food venues and the number of fast-food venues within a specified distance of the residence. Other studies have used perceived access [7, 57], secondary lists [11, 34, 35], or a combination of direct observation and telephone books . Prior work has shown that the use of secondary lists distorts representations of the food environment, and that ground-truthing is the most accurate measure [27, 40], especially in rural areas [27, 40]. Considering that the average distance to the nearest traditional fast-food restaurant was 5.8 miles and 3.2 miles to the nearest non-traditional fast-food outlet, walking time was an inappropriate measure in our rural area. Spatial access to fast food, using both proximity (distance to the nearest location) and coverage (number of fast-food locations) measures, was significantly better to non-traditional fast-food outlets than to traditional fast-food restaurants alone. On average, the distance to the nearest fast-food opportunity was nearly half the distance to the nearest fast-food restaurant. There was twice the number of all fast-food opportunities compared to traditional fast-food restaurants within all three buffer distances. This suggests that limiting measures of spatial access to traditional fast-food restaurants alone or to major chains may significantly underestimate "true" exposure to fast food . Our work overcomes limitations of prior studies that examined fast-food consumption, but failed to consider spatial access as a determinant [10, 46, 47].
Residential distance was associated with fast-food consumption. In regression models, after adjustment for personal characteristics, increased distance to the nearest traditional fast-food restaurant, non-traditional fast-food outlet, or all fast-food opportunities, was associated with decreased weekly frequency of fast-food meals. This is in contrast to the work of Jeffery and colleagues in an urban area where they found that proximity to the home was not related to frequency of fast-food consumption . In addition, coverage for traditional fast-food restaurants, non-traditional fast-food outlets, and all fast-food opportunities was associated with fast-food consumption, regardless of the coverage area. However, the magnitude of the association of coverage, or the number of the different venues, for traditional fast-food restaurants, non-traditional fast-food outlets, or all fast-food opportunities was almost three times greater with one-mile of the residence, compared with three- and five-mile buffer areas. This suggests that both proximity to the nearest fast-food venue and the number of different choices were associated with fast-food consumption. Further, proximity and coverage for non-traditional fast-food outlets had a similar independent association with fast-food consumption as traditional fast-food restaurants. It is possible that rural residents may be similarly attracted to traditional and non-traditional fast-food venues.
The interaction of gender and spatial access was associated with fast-food consumption, controlling for the independent association of gender and spatial access. The association of distance and coverage on fast-food consumption was greater for women than for men. For comparable increase in distance to the nearest traditional fast-food restaurant, non-traditional fast-food outlet, or any fast-food opportunity, the association for women was for a decrease in frequency of fast-food meals, compared with men. Similar significant associations were observed for coverage; the greater the coverage, the less frequent consumption of fast-food meals for women. The interaction revealed that proximity and coverage do not have the same direction of association as the independent effect of proximity and coverage. There may be gender-based inequities in access to transportation, and given the average distances to both traditional fast-food restaurants and non-traditional fast-food outlets, women without available transportation may visit fast-food destinations less often. The coefficients for interaction with traditional fast-food restaurants and non-traditional fast-food outlets were similar in magnitude, indicating an association on frequency of fast-food meal consumption among women. This finding may be associated with men and women having different travel activity patterns that are influenced by family and work demands, which also influence interactions within the environment [58–62]. The relationships between better access to fast food based on home residence and less frequent fast-food consumption for women may be related to less-frequent use of fast-food restaurants than men , and daily travel patterns. One possible explanation is that women may be less influenced by the food outlets nearest their home because of family, social, volunteer/professional responsibilities that require travel beyond a home-centered activity space; women's travel patterns may be more varied from accommodating to changing work schedules or family demands compared to men's, whose travel patterns between work and home are relatively more stable. Another possibility may be that women, who were less likely to be employed for wages than men, consumed less fast food because they spent more time at home or other locations where fast food was not readily available. Alternatively, women may have distinct motivations for seeking out fast food, which may explain these findings . Understanding men and women's interactions with the food environment in context with other behaviors and dimensions of the environment, such as the location and distribution of nonfood destinations (e.g., work, school, childcare facilities, banking and other service centers, and retail outlets), may elucidate the distinct relationship between access to fast food and consumption in men compared with women.
It is especially important to note that, in addition to spatial access to fast food, personal characteristics were significantly associated with frequent fast-food consumption. Overall, poverty status was associated with fewer fast-food meals. This is opposite of a previous finding that lower income was associated with more frequent fast-food use , and similar to one where higher income was associated with more frequent fast-food consumption .
Obesity was consistently associated with increased fast-food consumption. Prior studies have shown mixed results for the relationship between obesity and fast-food consumption [10, 11, 36]. Interestingly, three additional personal characteristics were not independently associated with fast-food consumption in our rural sample; namely, race/ethnicity, household size, and employment status. Correlations between these three characteristics and household income may explain the lack of statistical significance in the regression models.
There are several methodological strengths to this study. First, data for the location and availability of fast food in this large rural area were collected using ground-truthed methods, which have been shown to be more accurate in small-town and rural areas than secondary or publicly available lists [27, 40, 63]. Second, data were not restricted to fast-food restaurants or the major fast-food restaurant chains, but included all traditional fast-food restaurants and non-traditional fast-food outlets, such as convenience stores, supermarkets, and grocery stores that market fast-food meals. This provides a comprehensive picture of the fast-food environment. Third, our measures of access included two dimensions; namely, proximity (distance to the nearest location) and coverage (number of locations within a specified area). Finally, data on fast-food consumption was collected from a large sample of rural men and women who participated in a community health status assessment.
Although data permitted the examination of potential spatial access to fast food from the residence, travel patterns, car ownership, origin of food purchase trips, or distance to employment were not available in the data. It is not known whether other personal (e.g., fast-food preferences, available transportation) or environmental aspects, including the location and distribution of nonfood destinations (e.g., work, schools, banking and other service centers, retail outlets), may be more relevant than residential access and eating behavior measures for understanding fast-food consumption in rural women. Future work with rural families will allow documentation of other missing information, such as specific fast foods and amount consumed, location of fast-food purchase, and criteria for selecting fast-food outlet. As with other reports of food consumption, whether fast food or not, the assumption is that data represent "usual" intake, which may not be the case. A further limitation is the lack of definition of fast food in the survey and lack of validity that may result from a difference in perceived meaning of the term "fast food" among respondents. Finally, our rural study area may not be representative of other rural areas.