Respondents with some lifestyles (dietary habits: intend to lower oil intake, intend to lower salt intake, intend to lower sugar intake, and balanced diet and sports habits: moderate sport, a sport hobby, joining a fitness organization) had higher EQ-5D index and EQ VAS score, i.e., better HRQoL, compared with other respondents who don’t have the lifestyles. Balanced diet and moderate exercise every week were positively related to EQ-5D index and EQ VAS score. Clinical medical history and drinking history were negatively related to EQ-5D index and EQ VAS score. Intend to lower sugar intake, having at least one sport hobby were positively related to EQ-5D index, while sex (female as reference), BMI (unhealthy weight as reference), and intend to lower oil intake were positively related to EQ VAS score. People in Xizang and Guangxi provinces had lower average HRQoL. Small families (1-2 persons, 83.19 ± 20.14) had poorer HRQoL (EQ VAS score) than big families (≥3 persons, 85.00 ± 17.96, p <.05).
Strengths and weaknesses of the study
This study is the first one that collecting and analyzing data from family unit to assess HRQoL in mainland China. This study collected information from participants across the mainland China, which is, to the date, the widest sampling area in the researches about HRQoL in mainland China. This study is the first one to explore the correlation between HRQoL and dietary habits, sports habits across China.
This study has several limitations. First, we only use EQ-5D-5L questionnaire to assess individual’s HRQoL, but not comparing the effectiveness of other questionnaires. Second, our study revealed the correlation between lifestyle factors and HRQoL, but the causation hasn’t been revealed. Third, this study was conducted during the COVID-19 pandemic, the increased food price and long-term quarantine might affect people’s dietary intake and mental health respectively. Fourth, the questionnaire was only available for 10 days (October 21th to October 31th), which is relatively short and all in autumn. However, study showed that the seasonal changes in mood and behavior are associated with the HRQoL and mental well-being .
Strengths and weaknesses in relation to other studies
This study has shown that higher average HRQoL was found in people with dietary factors (intend to lower oil intake, intend to lower salt intake, intend to lower sugar intake, and balanced diet). The intend to lower oil intake lifestyle was negatively correlated to the HRQoL in Chinese people, which was similar to the previous study in Spain . It had revealed a detrimental relationship between trans saturated fatty acids intake and most of the mental domains (including vitality, social functioning and role emotional) of QoL [ 34]. However, physical diseases will undoubtedly impact people’s HRQoL. And there was no such research that systematically investigate the relationship between intend to lower oil intake and HRQoL in China before. The Harvard Health Publishing has reported that consuming too much sugar can raise blood pressure and increase chronic inflammation, both of which were pathological pathways to heart disease, and the impacted physical disease will affect HRQoL . Too much added sugar can be one of the greatest threats to chronic diseases, such as diabetes, heart disease, fatty liver disease, and some cancers. Study has shown that excess dietary sodium not only increase blood pressure, but also increase arterial stiffness, decrease glomerular filtration rate, increase left ventricular hypertrophy, and sensitized sympathetic neurons . As a result, elevated dietary sodium adversely affected target organs, including blood vessels, heart, kidneys and brain . Although the benefits of salt, sugar reduction and balanced diet had been proven and suggested by World Health Organization (including reducing blood pressure, risk of cardiovascular disease, stroke and coronary heart attach), there was no research that ever investigated the correlation between salt, sugar intake and HRQoL [38,39,40]. The result on balanced diet was consistent to the study in the past, which concluded that balanced diet improves quality of life and provides an adequate quantity of fermentable carbohydrates .
Respondents who had sports habits (including having a sport hobby, joining a fitness group and doing moderate exercise every week) had been revealed to have a better HRQoL, which was also consistent to the previous researches [42, 43]. Omorou, Y.A., et al had concluded in a study incorporating Frenches that sport was nearly always associated with better quality of life, even more so for people who has high physical activity levels . Another study indicated that high sports-active showed better scores on almost all dimensions of HRQoL than low-sports active children and non-sports club members, and frequency of sports is more relevant to HRQoL than the form of sports participation . A number of studies reported that HRQoL is reversely related to BMI [ 44–47]. Our study gave a positive correlation between BMI (unhealthy weight as reference) and EQ VAS score, and no correlation to the EQ-5D index. A study on Chinese population revealed that obesity impaired physical but not mental health . This unsignificant result on EQ-5D index may be due to the different impact of BMI on mental health and physical health (EQ-5D-5L questionnaire assesses both physical health and mental health).
We also found that in our study, male tend to have higher HRQoL. Many studies in the past revealed similar results, which reported that the HRQoL scores were poorer in female than male . This might account for the higher average educational background and the higher family pressure of female. Higher education background indicated greater competition, following with a busy life and less free time. At the same time, China had one of Asia-Pacific’s highest labor force participation rates for female, and female made up 43.7% of the total labor force in 2019 . Therefore, female shoulder both work and family tasks (including housework, childbirth, fostering children, etc).
The worse HRQoL in further southwest China might due to the relatively poorer economics status there . Study have reported that a higher QoL is found in wealthier nations .
The negative correlation between HRQoL and drinking history is consistent to some previous studies [53, 54]. However, there were studies reporting alcohol drinkers, including those with heavy drinking, reported better physical HRQoL than non-drinkers [55, 56]. This might be reverse causation, in which people with better physical HRQoL can get drunk, and non-drinkers cannot, for example, people who were ≤ 35 years old tend to be alcoholic and people who were > 55 years old tend to avoid alcohol due to decreased physical fitness.
Small families (1-2 persons) had statistically poorer HRQoL compared to big families (≥3 persons). As the sustained high pressure on work and life, many people in China have to delay conception or choose no kids . Therefore, the small family size may be a resultant factor of lower HRQoL.
The meaning of the study
For the future health policy planning, we suggest that the Chinese government should make reasonable efforts to improve healthy lives of the people, especially in the parts of health education and promotion through evidence-based medicine, such as the health-promoting factors in our results: reducing oil, salt and sugar intake, balanced diet, moderate exercise every week, joining a fitness organization and having at least one sports hobby. The government can consider using television programs to cultivate people’s healthy eating habits, building more sports facilities to encourage regular exercise . Investing the early childhood institutions and giving birth allowance are possible ways to alleviate people’s pressure and improve the average HRQoL of the population . All in all, the improvement of HRQoL for the Chinese people requires long-term and continuous efforts by both the government’s guidance and the people themselves to response and practice . We believe that this study provides a powerful and scientific evidence of Chinese people’s HRQoL and the related factors and might be helpful to the Chinese government in the health planning of China in the future.
Unanswered questions and future research
It is still not clear whether these lifestyle factors are causative or resultant to high HRQoL, and the underlying reasons are expected to be revealed in future researches. In the future, studies with larger sample size and different health scales are expected to investigate the impact of drinking on HRQoL.