Leeds Beckett University, Leeds, LS6 3QS, UK.
Leeds Beckett University, Leeds, LS6 3QW, UK.
Int J Health Geogr. 2021 Jul 28;20(1):34. doi: 10.1186/s12942-021-00287-9.
Obesity remains one of the most challenging public health issues of our modern time. Despite the face validity of claims for influence, studies on the causes of obesity have reported the influence of the food environment to be inconsistent. This inconsistency has been attributed to the variability of measures used by researchers to represent the food environments-Researcher-Defined Food Environments (RDFE) like circular, street-network buffers, and others. This study (i.) determined an individual's Activity Space (AS) (ii.) explored the accuracy of the RDFE in representing the AS, (iii.) investigated the accuracy of the RDFE in representing actual exposure, and (iv.) explored whether exposure to food outlet reflects the use of food outlets.
Data were collected between June and December 2018. A total of 65 participants collected Global Positioning System (GPS) data, kept receipt of all their food purchases, completed a questionnaire about their personal information and had their weight and height measured. A buffer was created around the GPS points and merged to form an AS (GPS-based AS).
Statistical and geospatial analyses found that the AS size of participants working away from home was positively related to the Euclidean distance from home to workplace; the orientation (shape) of AS was also influenced by the direction of workplace from home and individual characteristics were not predictive of the size of AS. Consistent with some previous studies, all types and sizes of RDFE variably misrepresented individual exposure in the food environments. Importantly, the accuracy of the RDFE was significantly improved by including both the home and workplace domains. The study also found no correlation between exposure and use of food outlets.
Home and workplace are key activity nodes in modelling AS or food environments and the relationship between exposure and use is more complex than is currently suggested in both empirical and policy literature.
肥胖仍然是我们现代面临的最具挑战性的公共卫生问题之一。尽管声称有影响的说法具有表面效度，但肥胖原因的研究报告称，食物环境的影响并不一致。这种不一致性归因于研究人员用来代表食物环境的各种措施的可变性——研究人员定义的食物环境（RDFE），如圆形、街道网络缓冲区等。本研究（i.）确定了个体的活动空间（AS）（ii.）探索了 RDFE 在代表 AS 方面的准确性，（iii.）调查了 RDFE 在代表实际暴露方面的准确性，以及（iv.）探讨了暴露于食物出口是否反映了食物出口的使用。
数据收集于 2018 年 6 月至 12 月期间进行。共有 65 名参与者收集了全球定位系统（GPS）数据，记录了他们所有的食物购买记录，完成了一份关于个人信息的问卷，并测量了他们的体重和身高。在 GPS 点周围创建了一个缓冲区，并将其合并形成一个 AS（基于 GPS 的 AS）。
统计和地理空间分析发现，离家工作的参与者的 AS 大小与家到工作场所的欧几里得距离呈正相关；AS 的方向（形状）也受到家到工作场所的方向的影响，个人特征不能预测 AS 的大小。与一些先前的研究一致，所有类型和大小的 RDFE 都不同程度地错误代表了个体在食物环境中的暴露情况。重要的是，通过同时包含家庭和工作场所两个领域，RDFE 的准确性得到了显著提高。该研究还发现，暴露与食物出口的使用之间没有相关性。
家庭和工作场所是建模 AS 或食物环境的关键活动节点，暴露与使用之间的关系比当前实证和政策文献中所表明的更为复杂。
