Department of Geography and Planning, University of Toronto, 100 St. George Street, Toronto, ON, M5S 3G3, Canada.
UKCRC Centre for Diet and Activity Research (CEDAR), MRC Epidemiology Unit, University of Cambridge School of Clinical Medicine, Box 285 Institute of Metabolic Science, Cambridge Biomedical Campus, Cambridge, CB2 0QQ, UK.
Int J Behav Nutr Phys Act. 2020 May 13;17(1):62. doi: 10.1186/s12966-020-00967-y.
Despite increased attention on retail food environments and fast food consumption, results from previous studies have been inconsistent. Variation in measurement of exposure to retail food environments and the context of the built environment are possible reasons for inconsistencies. The purpose of the current study is to examine the association between exposure to fast food environment and fast food consumption among young adults, and to explore possible associations between built environment and fast food consumption.
We employed an observational, cross-sectional study design. Cross-sectional surveys were conducted in 2016 and 2017. In a sample of 591 young adults aged 16-30 years in five Canadian cities, we constructed and computed individual-level time-weighted number and ratio of fast food outlets in activity spaces derived from GPS trajectory data. Negative binomial regression models estimated the associations between exposure measures and frequency of fast food consumption (number of times consuming fast food meals in a seven-day period), controlling for built environment characterization and individual-level characteristics.
Significant positive associations were found between time-weighted number of fast food outlets and count of fast food meals consumed per week in models using a radius of 500 m (IRR = 1.078, 95% CI: 0.999, 1.163), 1 km (IRR = 1.135, 95% CI: 1.024, 1.259), or 1.5 km (IRR = 1.138, 95% CI: 1.004, 1.289) around GPS tracks, when generating activity spaces. However, time-weighted ratio of fast food outlets was only significantly associated with count of fast food meals consumed when a radius of 500 m is used (IRR = 1.478, 95% CI: 1.032, 2.123). The time-weighted Active Living Environment Index with Transit measure was significantly negatively related to count of fast food meals consumed across all models.
Our study demonstrated associations of time-weighted activity space-based exposure to fast food outlets and fast food consumption frequency in a sample of young adults in urban Canada, and provides evidence of the association between context of built environment and fast food consumption, furthering discussion on the utility of individual-level, activity space-based data and methods in food environment research. These results imply that both food retail composition and activity spaces in urban areas are important factors to consider when studying diets.
尽管人们越来越关注零售食品环境和快餐消费，但先前的研究结果并不一致。暴露于零售食品环境和建筑环境背景下的测量差异可能是不一致的原因。本研究的目的是检验年轻成年人接触快餐环境与快餐消费之间的关联，并探讨建筑环境与快餐消费之间可能存在的关联。
我们采用观察性、横断面研究设计。2016 年和 2017 年进行了横断面调查。在加拿大五个城市的 591 名 16-30 岁的年轻成年人样本中，我们根据 GPS 轨迹数据构建并计算了个体活动空间内快餐网点的个体加权数量和比例。使用负二项回归模型，控制建筑环境特征和个体特征，估计暴露测量值与快餐消费频率（一周内食用快餐餐的次数）之间的关联。
在使用 500m（IRR=1.078，95%CI：0.999，1.163）、1km（IRR=1.135，95%CI：1.024，1.259）或 1.5km（IRR=1.138，95%CI：1.004，1.289）的 GPS 轨迹周围生成活动空间时，发现个体加权快餐网点数量与每周快餐消费次数呈显著正相关。然而，当使用 500m 半径时，个体加权快餐网点比例仅与快餐消费次数显著相关（IRR=1.478，95%CI：1.032，2.123）。所有模型中，个体加权的活跃生活环境指数与过境指标均与快餐消费次数呈显著负相关。
本研究在加拿大城市的年轻成年人样本中，证明了基于活动空间的个体加权快餐网点暴露与快餐消费频率之间的关联，并提供了建筑环境背景与快餐消费之间关联的证据，进一步讨论了个体水平、基于活动空间的数据和方法在食品环境研究中的应用。这些结果表明，在研究饮食时，城市地区的食品零售组成和活动空间都是需要考虑的重要因素。
