Does exposure reflect the use of food outlets? Exploring the influence of exposure on the use of food outlets

In the past five decades, the developed nations have experienced a change in their food environments characterised by increased access to energy-dense food ^1,2. Although the concept of environmental influence on obesity is appealing, the evidence to support it is still inconsistent ^3,4.

In the food environment literature, there is a notion that increased exposure to ‘unhealthy’ food outlets like fast-food outlets could increase the likelihood of ‘unhealthy food’ consumption leading to an increased risk of obesity. A study by Burgoine et al.⁵ revealed that exposure to takeaway food outlets in close proximity to the home, work, and commuting environments combined was linked to marginally higher consumption of takeaway food, greater body mass index, and greater odds of obesity. Similarly, a study by Sadler et al.⁶ in adolescents showed that exposure to ‘unhealthy food outlets’ between home and school produced a significantly increased likelihood of consumption of junk food. The downside of these studies is that they did not explore the relationship between the exposure and use of food outlets, nor whether the stores classified as ‘unhealthy’ were the major contributor to the increased purchase and consumption of junk food. It is worth noting that the so-called “healthy” food outlets like supermarkets and “unhealthy” food outlets like convenience stores can sell or serve both healthy and unhealthy food options or portions.⁷ The study conducted by LBU which was published in the International Journal of Health Geography,⁸ was conducted to investigate whether exposure to food outlets is associated with purchase of food in those food outlets.

We tracked participants’ daily movements using Global Positioning System (GPS) and food purchase locations using receipt of food purchases for seven days. The analysis showed that supermarkets were the food outlets most visited during the study period (54%), while convenience stores (16%) and fast-food outlets (9%) were the outlets least visited. Meanwhile, participants had the highest exposure to ‘other’ food outlets (i.e. cafés and coffee shops, speciality food stores, pubs and inns, grocery stores, hotels and restaurants) in their activity-based food environment[1] (53%) followed by fast-food outlets (25%) and the least exposure was to supermarkets (2%). Despite high exposure to ‘other’ and ‘fast-food’ outlets, participants used these food venues relatively rarely; most food purchases were made at supermarkets, whereas they made the fewest food purchases from fast-food outlets.

These findings align with Appelhans et al.⁸ who found supermarket stores to be the most visited food outlets while fast-food/takeaway outlets were the least visited food venues. From the analysis, exposure to food outlets was not related to their use. This suggests that mere exposure to a certain type of food outlet may not necessarily lead to the use of those facilities ⁹. The mechanism by which exposure influences use is likely to be more complex than has been suggested by most contemporary research. Recently, the Office for National Statistics (ONS) reported an increased cost of living and food price across the Great Britain.¹⁰ This for example could have an impact on individuals’ decisions on the type of food they purchase and food outlets they visit. Glanz et al.¹¹ highlighted taste, cost, convenience, variety and energy density as some of the key determinants of food choices. These factors may be objective, subjective or both, powerfully influencing individuals’ food choices and purchase locations.

Several studies on the food environment suggest that exposure to certain types of food outlets increases the likelihood of obesity.^5,12–14. These studies operate under the assumption that some food outlets are ‘healthy’ while others are ‘unhealthy’.¹⁵ Often, fast-food outlets, takeaways and convenience stores are classified as ‘unhealthy’, whereas grocery stores and supermarkets are considered ‘healthy’.¹⁵ This stratification of food outlets is overly simplistic and problematic as it fails to recognise the wide array of unhealthy food options offered within most supermarkets while disregarding the healthy food options available at most fast-food outlets.¹⁵. A study by Lesser et al.¹⁶ demonstrated that the average number of calories purchased by participants at McDonald’s (1,038 calories)—considered ‘unhealthy’— was almost the same as the calories purchased at Subway (955 calories)—considered as ‘healthy’. The so-called ‘health halo’ ¹⁷ can spuriously imply that certain specific food outlets are ‘healthier’. Importantly, the ‘healthiness’ of food outlets is determined by the actual food offered by the food outlets.¹⁵

Thus, exposure to food outlets was not a good determinant of their use. Clearly, the relationship between exposure and use is more complex than is currently suggested in both empirical and policy literature. With an increased impetus to modify the food environment, we suggest a shift of focus in the food environment field from mere exposure to food outlets to more nuanced factors like the quality of food offerings by food outlets as well as the quality and quantity of food purchased and consumed by people.

[1] Activity-based food environment includes all possible opportunities to acquire/consume food in a set of locations regularly visited in the course of conducting the business of daily living, along with the routes taken to and from these places.¹⁸

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