No abstract

BMI, waist circumference (WC) and waist-to-height ratio (WHtR) can be used for discriminating children and adolescents at risk of CVD. However, consensus on how to use these anthropometric indicators is lacking for children and adolescents in Asia. Discrete criteria are promoted internationally, but continuous variables could be used. Data from a survey of 10 949 Vietnamese school-aged children (6–18 years) were used to evaluate the performance of anthropometric indicators to identify elevated blood pressure (BP), dyslipidaemia or at least three cardiovascular risk factors (CVRF). Weight, height, WC and BP were measured using standardised protocols; 1009 participants who had blood lipids were analysed. AUC was used to assess the performance, and the Youden index to identify optimal cut-offs. The prevalence of elevated BP, dyslipidaemia and CVRF was 26·5, 49·3 and 12·2 %, respectively. BMI, WC and WHtR had low capacity to identify elevated BP and dyslipidaemia (AUC range 0·61–0·66) but moderate capacity to identify CVRF (0·72–0·74). Optimal BMIZ cut-offs to identify elevated BP, dyslipidaemia and CVRF were 0·40, 1·01 and 1·1 sd; for WC z-score, they were 0·06, 0·49 and 0·62 sd; for WHtR, optimal cut-offs were close to 0·5. A BMIZ cut-off of 1·0 sd and a WHtR cut-off of 0·5 would, therefore, be useful criteria to identify Vietnamese children who are likely to have CVRF. However, further validation of these criteria in other studies of Asian children and adolescents is needed.

Global trade has shaped food systems over centuries, but modern trade agreements are hastening these changes and making them more complex, with implications for public health and nutrition transition. This study aimed to understand the impact of the 2018 Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP) on the policy space for public health nutrition in Vietnam. We conducted comparative document review and key informant interviews, and our analysis drew on a framework of policy space and the theory of advocacy coalitions. We identified 10 CPTPP sections with potential public health nutrition implications; and 50 Vietnamese policies relevant to nutrition having one or more tensions with one or more CPTPP sections. A majority of policy tensions were in sections of the CPTPP relating to technical barriers to trade and government procurement; most tensions related to protecting policy-making from vested interests. Different groups of policy actors hold different beliefs and interests on these issues, and therefore promote different framings and policy approaches. We identified two advocacy coalitions working very separately on issues affecting nutrition policy space: a trade coalition holding the policy position that free trade improves nutrition by default; and a nutrition coalition holding the policy position that nutrition should be explicitly considered in trade policy. The policy space for nutrition in Vietnam has important potential constraints through written policy, and the trade and nutrition coalitions will need to interact more regularly and constructively in order to foresee where these tensions will arise in practice, and create plans for their mitigation. This study adds to global evidence of free trade agreement impacts on nutrition policy space, and we extend previous work by explaining these actor groupings in the policy space through the theory of advocacy coalitions.

Childhood overweight and obesity are rapidly increasing in urban Vietnam. Dietary patterns are understudied for their association with obesity risk in these children, and it is unclear which parental and societal factors should be targeted in prevention efforts. The study assessed child characteristics, dietary patterns, parental and societal factors for associations with childhood overweight and obesity status in Ho Chi Minh City, Vietnam. A sample of 221 children aged 9–11 years was randomly selected from four Ho Chi Minh City primary schools. Weight, height and waist circumference were measured using standardized methods. Three 24‐h dietary recalls were collected from 124 children, which were used to assess dietary patterns using principal component analysis (PCA). Parents completed a questionnaire about child, parental and societal factors. The overall prevalence of obesity was 31.7% and of combined overweight and obesity 59.3%. Three main dietary patterns from 10 food groups were identified by PCA: traditional (grains, vegetables, meat and meat alternatives), discretionary (snacks and sweetened beverages), and industrialized (fast food and processed meat). Children with higher discretionary diet scores had higher odds of being overweight. Being a boy, screen time over 2 h/day, parental underestimation of child weight status, father's obesity, and household income in the lowest quintile were positively associated with childhood obesity. Future intervention programmes in Vietnam need to consider targeting children's unhealthy diets and parental perceptions of child weight status, as well as focusing on upstream approaches that reduce inequities contributing to childhood obesity and concomitant dietary patterns.