Nutrition literacy plays an important role in children's dietary habits and nutrition. This study aimed to analyse the status of nutrition literacy and its influencing factors amongst middle school students in Chongqing, China. “Nutrition literacy scale for middle school students in Chongqing” was used in 29 districts of Chongqing in September 2020. The scores of nutrition literacy and its' three sub-domains (functional, interactive and critical nutrition literacy) were divided into low and high groups based on their median scores. Binary logistic regression was used to measure the influencing factors of nutrition literacy. A total of 18,660 middle school students were included in this study. The median of nutrition literacy of middle school students was 61.68 (IQR = 14.37). Interactive nutrition literacy had the highest score (median = 70.00, IQR = 20.00), followed by functional nutrition literacy (median = 68.69, IQR = 14.14) and critical nutrition literacy (median = 45.83, IQR = 25.00). Students who were the minority (OR = 0.71, 95% CI = 0.637–0.785), in senior high school (OR = 0.51, 95% CI = 0.477–0.548), in rural areas (OR = 0.85, 95% CI = 0.790–0.911), receiving school meal support from the government (OR = 0.63, 95% CI = 0.591–0.664), with other caregivers' parenting (OR = 0.86, 95% CI = 0.805–0.914), with parents having a low level of education and with an abnormal BMI [thin (OR = 0.91, 95% CI = 0.837–0.990), overweight (OR = 0.87, 95% CI = 0.785–0.968), and obese (OR = 0.83, 95% CI = 0.767–0.902)] presented less probability of being a high level of nutrition literacy. Our results could assist public health authorities in developing strategies of nutrition literacy promotion for references and theoretical foundations.

The effect of selenium on hypertension is inconclusive. We aimed to study the relationship between selenium intake and incident hypertension. Adults (age ≥20 years) in the China Health and Nutrition Survey were followed up from 1991 to 2011 (N = 13,668). The latent class modeling method was used to identify trajectory groups of selenium intake. A total of 4039 respondents developed hypertension. The incidence of hypertension was 30.1, 30.5, 30.6, and 31.2 per 1000 person-years among participants with cumulative average selenium intake of 21.0 ± 5.1, 33.2 ± 2.8, 43.8 ± 3.6, and 68.3 ± 25.2 µg/day, respectively. Region and selenium intake interaction in relation to hypertension was significant. In the multivariable model, cumulative intake of selenium was only inversely associated with the incident hypertension in northern participants (low selenium zone), and not in southern participants. Compared to selenium intake trajectory Group 1 (stable low intake), all three trajectory groups had a low hazard ratio for hypertension among the northern participants. However, Group 4 (high intake and decreased) showed an increasing trend of hypertension risk in the south. In conclusion, the association between selenium intake and the incidence of hypertension varied according to regions in China. In the low soil selenium zone, high selenium intake might be beneficial for hypertension prevention.

Purpose Few studies have yet examined sleep quality among puerperal women during the coronavirus disease 2019 pandemic. This cross-sectional study aimed to compare the sleep quality of puerperal women before and during the COVID-19 pandemic in Lanzhou, China. The study exploreed the factors that affect sleep quality among puerperal women. Methods The study population comprised puerperal women who went to the obstetric department of the Gansu Provincial Maternity and Childcare Hospital on the 42nd day after childbirth. Sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI). Data were collected by doctors in the obstetric department before the COVID-19 pandemic (Oct.-Dec. 2019) and during the COVID-19 pandemic (Feb.-Apr. 2020) in China. Multiple linear regressions were used to examine the association between the sleep quality of puerperal women and COVID-19 and to identify factors that affect the total PSQI scores. Results In 2019, 546 puerperal women were assessed compared with 655 who were assessed in 2020. Compared with before COVID-19, the total PSQI scores of puerperal women improved during the COVID-19 pandemic. In addition, the influencing factors of sleep quality among puerperal women were the pandemic itself, age, conception method, and postpartum depression (PPD). Conclusions In contrast with other studies, there was no evidence for worsening sleep quality of puerperal women during the COVID-19 pandemic in Lanzhou, China. Puerperal women who underwent assisted pregnancy or developed PPD were more likely to experience poor sleep quality.

Background: This study aims to examine the effects of Television (TV) food advertisements (ads) related purchasing behaviours on children’s dietary intake, overweight and obesity in China. Methods: Data from 1,417 children (aged 6–17.99 years) in the 2011 China Health and Nutrition Survey were analysed. TV food ads related purchasing behaviours were assessed through the frequency of children’s requests to purchase advertised foods and the frequency of parents’ purchases of these advertised foods, as well as the frequency of children’s purchases of advertised foods. The height and weight of children were measured. Logistic regression models were used to identify the associations between TV food ads related purchasing behaviours and overweight/obesity of children.Results: TV food ads related purchasing behaviours were positively associated with children’s dietary intake of energy, protein, fat and carbohydrates. After adjusting for potential confounding factors, TV food ads related purchasing behaviours were positively associated with children’s overweight/obesity: OR (95% CI) for overweight/obesity were: 1.46 (1.01–2.11) for children purchasing advertised foods, 1.59 (1.15–2.18) for parents purchasing advertised foods for their children and 1.39 (0.99–1.95) for children requesting advertised foods.Conclusions: TV food ads related purchasing behaviours are associated with children’s dietary intake. Moreover, TV food ads related purchasing behaviours can increase the risk of overweight and obesity of children. Regulations on TV food ads should be considered in China.

Background A high intake of salt is a major risk factor for cardiovascular diseases. Despite decades of effort to reduce salt consumption, the salt intake in China is still considerably above the recommended level. Thus, this study aims to design and implement an intelligent household added salt monitoring system (SALTCHECKER) to monitor and control added salt consumption in Chinese households. Methods A randomized controlled trial will be conducted among households to test the effect of a SALTCHECKER in Chongqing, China. The test modalities are the SALTCHECKER (with a smart salt checker and a salt-limiting WeChat mini programme) compared to a salt checker (with only a weighing function). The effectiveness of the system will be investigated by assessing the daily added salt intake of each household member and the salt consumption-related knowledge, attitude and practice (KAP) of the household’s main cook. Assessments will be performed at baseline and at 3 and 6 months. Discussion This study will be the first to explore the effect of the household added salt monitoring system on the reduction in salt intake in households. If the intelligent monitoring system is found to be effective in limiting household added salt consumption, it could provide scientific evidence on reducing salt consumption and preventing salt-related chronic diseases. Trial registration Chinese clinical trial registry (Primary registry in the World Health Organization registry network): ChiCTR1800018586. Date of registration: September 25, 2018.

Background: Lifestyle behaviours of students from schools in different socioeconomic areas may be different. Few studies have investigated such topics in China. This study aimed to explore the differences in lifestyle behaviours between inner urban high school students (IUHSSs) and peri-urban high school students (PUHSSs). Methods: A cross-sectional survey based on a self-report questionnaire was administered among 1560 high school students (726 from inner urban high schools and 834 from peri-urban high schools) in Chongqing, China. Physical activity, sleep time, screen time and dietary behaviours were assessed according to a series of recommendations of Chinese guidelines. Results: No significant difference was found in meeting the recommendation for daily physical activity between IUHSSs and PUHSSs (7.6% vs. 6.8%, p > 0.05). PUHSSs were more likely to meet the recommendations of weekdays’ sleep time (14.9% vs. 5.4%, p < 0.001), weekdays’ and weekends’ screen time (85.4% vs. 76.7%, p < 0.001; 21.1% vs. 14.3%, p < 0.001), and had higher proportion of high-score group of dietary behaviours (58.6% vs. 36.4%, p < 0.001) than those of IUHSSs. IUHSSs were more likely to meet the recommendation of weekends’ sleep time (75.6% vs. 67.9%, p < 0.001) than that of PUHSSs. Conclusions: A low proportion met the recommendations of physical activity, weekdays’ sleep time and weekends’ screen time among high school students in Chongqing, China. Lifestyle behaviours may differ between inner urban and peri-urban high school students. Additional support or targeted health education should be provided by high schools to improve the lifestyle behaviours of students, especially in inner urban districts.

Background This study aims to examine the effects of the request and purchase of Television (TV) advertised foods on children’s dietary intake, overweight and obesity in China. Methods Data from 1417 children (aged 6–17 years) in the 2011 China Health and Nutrition Survey were analysed. The request and purchase of TV advertised foods were assessed through the frequency of children’s requests to purchase TV advertised foods and the frequency of parents’ purchases of these advertised foods, as well as the frequency of children’s purchases of TV advertised foods. The height and weight of children were measured. Logistic regression models were used to identify the associations between the request and purchase of TV advertised foods and overweight/obesity of children. Results The request and purchase of TV advertised foods were positively associated with children’s dietary intake of energy, protein, fat and carbohydrates. After adjusting for potential confounding factors, children’s request and purchase of TV advertised foods and parent’s purchase of TV advertised foods were positively associated with children’s overweight/obesity: odds ratio (OR) and 95% confidence interval (CI) for overweight/obesity were: 1.46 (1.01–2.11) for children purchasing advertised foods ≥1 time/week, 1.59 (1.15–2.18) for parents purchasing advertised foods for their children ≥1 time/week and 1.39 (1.00–1.95) for children requesting advertised foods ≥1 time/week. Conclusions The request and purchase of TV advertised foods are associated with children’s dietary intake. Moreover, the request and purchase of TV advertised foods can increase the risk of overweight and obesity of children. Health education involving children’s request and purchase of TV advertised foods and parents’ purchase of TV advertised foods should be considered in China.

Background and Purpose: Exploring the differences of children's dietary behaviours from different nationalities could provide a reference for targeted nutritional interventions. This study aims to assess the dietary behaviours among Han, Tujia and Miao primary school students and the differences among the ethnic groups. Materials and Methods: This cross-sectional survey included 556 primary school students (249 Han, 76 Tujia and 231 Miao students) aged 6-13 years from the representative minority areas of Chongqing, China. Data were collected with a self-administered or one-on-one interview-based questionnaire encompassing questions on sociodemographics, eating habits and dietary intake. Eating habits and dietary intake were categorized into health-protective and health-risk dietary behaviours. χ 2 tests were conducted to examine the differences in eating habits and dietary intake among the three ethnic groups. Forward stepwise logistic regression models were performed to check the factors affecting dietary intake. Results: Fewer than half of the students had health-protective dietary behaviours in terms of rice, fruit, fish, eggs and milk intake. Compared with Han students, Tujia students were more likely to meet the recommended intake of vegetables (OR = 2.13, 95% CI [1.22-3.69]), less likely to meet the recommended intake of meat (OR = 0.58, 95% CI [0.35-0.94]) and fish (OR = 0.55, 95% CI [0.32-0.94]); Miao students were more likely to meet the recommended intake of vegetables (OR = 1.73, 95% CI [1.20-2.51]), fruits (OR = 1.62, 95% CI [1.16-2.28]) and water (OR = 1.59, 95% CI [1.12-2.26]) than those of Han students. Conclusion: The low proportion of health-protective dietary behaviours among primary school students from Han, Tujia and Miao ethnicities was found in this study. There were differences in dietary behaviours among the three ethnic groups. This study could provide a reference for implementing national dietary guidelines in consideration of socioeconomic status, ways of preparing and consuming foods, traditional foods and customs of different ethnic groups.