Adhere to the Chinese dietary guidelines associated with better subjective well-being: evidence from a cross-sectional survey and a daily diary investigation

Abstract Background Subjective well-being (SWB) plays an essential role in general health. Although beneficial effects of selected micronutrients and foods on SWB have been reported, they do not reflect the impact of the habitual diet on SWB. Therefore, the purpose of this study is to investigate the association between adherence to the Chinese Dietary Guidelines (CDG) with SWB. Methods This study combined a cross-sectional survey and a daily diary investigation. The cross-sectional survey was conducted on 1,433 students from 8 universities in southern China between October and November 2020. The daily diary investigation was conducted in November 2022, collecting 10-day daily data from 115 students at two universities in southern China over ten consecutive days, resulting in 1,020 valid matched daily responses. Adherence to the CDG was assessed by the China Prime Diet Quality Score (CPDQS), SWB was measured by the Index of Well-being (IWB) and the Affect Valuation Index (AVI). Correlation analysis, multiple regression analyses, and hierarchical regression were conducted to examine the associations of adherence to the CDG with its components, and SWB. Results The cross-sectional survey revealed significant predictors of SWB, including adherence to the CDG ( β = 0.24, p <0.001) and its components: cereals and tubers ( β = 0.07, p = 0.024), vegetables and fruits ( β = 0.11, p <0.001), dairy/soy/nuts ( β = 0.11, p = 0.002), and condiments and alcoholic beverages ( β = 0.08, p = 0.002). The daily diary investigation showed positive associations between adherence to the CDG ( β = 0.19, p <0.001), and its components: vegetables and fruits ( β = 0.11, p = 0.001), dairy/soy/nuts ( β = 0.06, p = 0.009), animal source food ( β = 0.06, p = 0.026), and condiments and alcoholic beverages ( β = 0.07, p = 0.026), with higher levels of daily SWB. Conclusions Adherence to healthy dietary patterns such as the CDG, rather than focusing on individual components in isolation, is associated with better SWB. Furthermore, the consumption of CDG components had an impact on SWB, although the specific effects varied between the two studies. This study offers modest evidence supporting the role of the CDG in promoting positive mental health.