Centre for Research and Action in Public Health, Health Research Institute, University of Canberra, Bruce, ACT, Australia.
Spatial Epidemiology & Evaluation Research Group, School of Health Sciences and Centre for Population Health Research, University of South Australia, Adelaide, Australia.
Int J Behav Nutr Phys Act. 2018 May 18;15(1):44. doi: 10.1186/s12966-018-0675-3.
Descriptive norms (what other people do) relate to individual-level dietary behaviour and health outcome including overweight and obesity. Descriptive norms vary across residential areas but the impact of spatial variation in norms on individual-level diet and health is poorly understood. This study assessed spatial associations between local descriptive norms for overweight/obesity and insufficient fruit intake (spatially-specific local prevalence), and individual-level dietary intakes (fruit, vegetable and sugary drinks) and 10-year change in body mass index (BMI) and glycosylated haemoglobin (HbA).
HbA and BMI were clinically measured three times over 10 years for a population-based adult cohort (n = 4056) in Adelaide, South Australia. Local descriptive norms for both overweight/obesity and insufficient fruit intake specific to each cohort participant were calculated as the prevalence of these factors, constructed from geocoded population surveillance data aggregated for 1600 m road-network buffers centred on cohort participants' residential addresses. Latent growth models estimated the effect of local descriptive norms on dietary behaviours and change in HbA and BMI, accounting for spatial clustering and covariates (individual-level age, sex, smoking status, employment and education, and area-level median household income).
Local descriptive overweight/obesity norms were associated with individual-level fruit intake (inversely) and sugary drink consumption (positively), and worsening HbA and BMI. Spatially-specific local norms for insufficient fruit intake were associated with individual-level fruit intake (inversely) and sugary drink consumption (positively) and worsening HbA but not change in BMI. Individual-level fruit and vegetable intakes were not associated with change in HbA or BMI. Sugary drink consumption was also not associated with change in HbA but rather with increasing BMI.
Adverse local descriptive norms for overweight/obesity and insufficient fruit intake are associated with unhealthful dietary intakes and worsening HbA and BMI. As such, spatial variation in lifestyle-related norms is an important consideration relevant to the design of population health interventions. Adverse local norms influence health behaviours and outcomes and stand to inhibit the effectiveness of traditional intervention efforts not spatially tailored to local population characteristics. Spatially targeted social de-normalisation strategies for regions with high levels of unhealthful norms may hold promise in concert with individual, environmental and policy intervention approaches.
描述性规范（他人的行为）与个体层面的饮食行为和健康结果有关，包括超重和肥胖。描述性规范因居住区域而异，但规范的空间变化对个体饮食和健康的影响知之甚少。本研究评估了超重/肥胖和水果摄入不足的局部描述性规范（特定于当地的流行率）与个体饮食摄入（水果、蔬菜和含糖饮料）以及 10 年内体重指数（BMI）和糖化血红蛋白（HbA）变化之间的空间关联。
在南澳大利亚阿德莱德的一个基于人群的成年队列（n=4056）中，临床测量了三次 HbA 和 BMI，时间跨度为 10 年。针对每个队列参与者的超重/肥胖和水果摄入不足的局部描述性规范，通过对以队列参与者居住地址为中心的 1600 米道路网络缓冲区的人群监测数据进行地理编码来构建，计算为这些因素的流行率。潜在增长模型估计了局部描述性规范对饮食行为以及 HbA 和 BMI 变化的影响，同时考虑了空间聚类和协变量（个体水平的年龄、性别、吸烟状况、就业和教育以及区域水平的家庭收入中位数）。
局部描述性超重/肥胖规范与个体水果摄入（负相关）和含糖饮料消费（正相关）以及 HbA 和 BMI 恶化有关。特定于当地的水果摄入不足的规范与个体水果摄入（负相关）和含糖饮料消费（正相关）以及 HbA 恶化有关，但与 BMI 变化无关。个体水果和蔬菜摄入量与 HbA 或 BMI 的变化无关。含糖饮料的消耗也与 HbA 的变化无关，而是与 BMI 的增加有关。
超重/肥胖和水果摄入不足的不利局部描述性规范与不健康的饮食摄入以及 HbA 和 BMI 恶化有关。因此，与生活方式相关规范的空间差异是设计人群健康干预措施时需要考虑的一个重要因素。不利的地方规范会影响健康行为和结果，并可能阻碍未针对当地人口特征进行空间调整的传统干预措施的效果。针对不健康规范水平较高的地区，实施有针对性的社会去正常化策略，可能与个人、环境和政策干预措施一起具有前景。
