Food choice motives by income group.

Background
The increased prevalence of overweight and obesity, along with high diet diversity, is observed among higher socio-economic groups in Sub-Saharan Africa. One contributing factor to these observed variations is food choice motives. However, the role of these motives in explaining the observed differences has not been thoroughly explored in this context.
Objective
This study investigates whether there are significant differences in food choice motives among socio-economic groups and whether these variations can partly explain the socio-economic disparities in diet diversity and overweight and obesity outcomes.
Methods
This study utilizes cross-sectional data from four counties in Kenya: Kiambu, Murang’a, Uasin Gishu, and Nakuru. The survey employed a three-stage cluster sample design to gather data using structured questionnaires on food choice motives, diet diversity, and anthropometrics from 381 adults in 2022. The mediating effects of 8 food choice motives (health, mood, convenience, sensory appeal, natural content, price, weight control, and familiarity) were analyzed using the Karlson-Holm-Breen method.
Results
The results show that individuals with higher household incomes place greater importance on health, mood, sensory, and weight concerns. The probability of an overweight and obesity outcome increases by 19% for a standard deviation change in the asset score, and by 8% for a standard deviation change in the years of schooling. Sensory motives significantly mediated these relationships. Sensory motives explained 29% of the income-BMI association and 30% of the education-BMI relationship. Higher education was also associated with increased diet diversity (β = 0.36, P < 0.001) mediated by higher health and sensory concerns.
Conclusions
The findings suggest significant differences in food choice motives among socio-economic groups, which contribute to outcomes such as overweight and obesity. Therefore, educational and other policies aimed at reducing obesity should also address food choice motives, while considering the disparities among socio-economic segments within populations.

研究背景
撒哈拉以南非洲的较高社会经济群体中，超重与肥胖患病率上升、饮食多样性提升的现象愈发显著。食物选择动机是导致这类群体间差异的潜在影响因素之一，但目前针对该背景下此类动机对差异的解释作用尚未得到充分探究。
研究目的
本研究旨在探究不同社会经济群体间的食物选择动机是否存在显著差异，且此类差异能否部分解释饮食多样性、超重与肥胖结局方面的社会经济不平等。
研究方法
本研究采用肯尼亚基安布（Kiambu）、穆兰加（Murang’a）、乌阿辛吉苏（Uasin Gishu）及纳库鲁（Nakuru）四个郡的横断面数据。2022年，本研究通过三阶段整群抽样设计，依托结构化问卷收集了381名成年人的食物选择动机、饮食多样性及人体测量学相关数据。本研究采用卡尔松-霍尔姆-布林（Karlson-Holm-Breen）法，分析了8项食物选择动机（健康、情绪、便利性、感官吸引力、天然成分、价格、体重控制及熟悉度）的中介效应。
研究结果
研究结果显示，家庭收入更高的群体对健康、情绪、感官体验及体重管理的重视程度更高。资产得分每增加1个标准差，超重与肥胖的发生概率提升19%；受教育年限每增加1个标准差，该概率提升8%。感官动机对上述关联具有显著中介效应：感官动机可解释29%的收入-身体质量指数（BMI）关联，以及30%的教育-BMI关联。更高的受教育水平还与饮食多样性提升相关（β=0.36，P<0.001），且该关联受到健康关注度与感官关注度提升的中介调控。
研究结论
本研究结果表明，不同社会经济群体的食物选择动机存在显著差异，而此类差异会对超重与肥胖等结局产生影响。因此，旨在降低肥胖率的教育政策及其他相关政策，在制定过程中应兼顾食物选择动机，并充分考虑人群内部不同社会经济群体间的不平等问题。