Dose-Response Relationship between Western Diet and Being Overweight among Teachers in Malaysia.

The rising prevalence of overweight and obesity is partly due to nutrition transition. The reported association between dietary patterns and overweight/obesity has been controversial because of inconsistent results and weak observed associations. Although it has been hypothesized that an unhealthy diet can increase obesity risk, none of the previous studies have examined the dose-response association using nonlinear dose-response analyses. This study aimed to examine the dose-response association between major dietary patterns and overweight/obesity. This was a cross-sectional study involving teachers selected through stratified multistage sampling from public schools in three Malaysian states. Dietary intake was assessed using a food frequency questionnaire, and two major dietary patterns (Western and Prudent diet) were extracted using factor analysis. Logistic regression followed by trend analysis was used to test the difference in odds of overweight and obesity in each quintile of diet score. A further analysis using restricted cubic spline models was performed to examine the dose-response associations of dietary patterns with odds of overweight/obesity. The logistic regression analysis showed that participants with the highest quintile of Western diet score were 1.4 times more likely to be overweight/obese compared to those in the lowest quintile (95% CI: 1.11, 1.83, p-trend < 0.001). The odds of overweight/obesity showed a significant increasing trend across quintiles of Western diet among both men and women (p-trend < 0.001). In the dose-response analysis, a positive linear association (Pnonlinearity = 0.6139) was observed where overweight/obesity was more likely to occur among participants with a Western diet score greater than a mean score of zero. There was an inverse trend of odds of overweight/obesity across quintiles of Prudent diet score, significant only for men (p for trend < 0.001). Linear association was found between Prudent diet score and odds of overweight/obesity among both men (Pnonlinearity = 0.6685) and women (Pnonlinearity = 0.3684) in the dose-response analysis. No threshold at the level of adherence to Prudent diet was linked to odds of overweight/obesity. Dose-response analysis indicated that women with a Western diet score greater than zero were more likely to be overweight or obese among women. In men, higher adherence to Western diet was associated with increased odds of overweight/obesity, while greater adherence to Prudent diet decreased the odds of overweight/obesity. Promoting and enhancing the consumption of Prudent diet and limit in Western diet may be used to guide the development of evidence-based diet interventions to curb overweight and obesity.

Consistency and Generalizability of Dietary Patterns in a Multiethnic Working Population.

BACKGROUND: Dietary pattern analysis is a complementary method to nutrient analysis in evaluating overall diet-disease hypotheses. Although studies have been conducted to derive dietary patterns among Malaysians, their consistency across subgroups has not been examined. OBJECTIVE: The study aimed to derive dietary patterns empirically and to examine the consistency and generalizability of patterns across sex, ethnicity, and urban status in a working population. DESIGN: This was a cross-sectional study using data from the Clustering of Lifestyle Risk Factors and Understanding its Association with Stress on Health and Well-Being among School Teachers in Malaysia study collected between August 2014 and November 2015. Dietary intake was assessed using a food frequency questionnaire, and dietary patterns were derived using factor analysis. PARTICIPANTS/SETTING: Participants were teachers from selected public schools from three states in Peninsular Malaysia (n=4,618). MAIN OUTCOME MEASURES: Dietary patterns derived using factor analysis. STATISTICAL ANALYSES PERFORMED: Separate factor analysis was conducted by sex, ethnicity, and urban status to identify dietary patterns. Eigenvalue >2, scree plot, Velicer's minimum average partial analysis, and Horn's parallel analysis were used to determine the number of factors to retain. The interpretability of each dietary pattern was evaluated. The consistency and generalizability of dietary patterns across subgroups were assessed using the Tucker congruence coefficient. RESULTS: There was no subgroup-specific dietary pattern found. Thus, dietary patterns were derived using the pooled sample in the final model. Two dietary patterns (Western and Prudent) were derived. The Western dietary pattern explained 15.4% of total variance, characterized by high intakes of refined grains, animal-based foods, added fat, and sugar-sweetened beverages as well as fast food. The Prudent dietary pattern explained 11.1% of total variance and was loaded with pulses, legumes, vegetables, and fruits. CONCLUSIONS: The derived Western and Prudent dietary patterns were consistent and generalizable across subgroups of sex, ethnicity, and urban status. Further research is needed to explore associations between these dietary patterns and chronic diseases.

Validation of a food frequency questionnaire to assess dietary cholesterol, total fat and different types of fat intakes among Malay adults.

BACKGROUND: Cardiovascular diseases are the major cause of death in Malaysia. Evidence shows that dietary fat intake is one of the important risk factors for cardiovascular disease. However, studies assessing the association of fatty acids and risk of cardiovascular diseases in Malaysia are scarce. Therefore, this study aimed to develop and validate a food frequency questionnaire (FFQ) assessing total fat and different types of fat among Malay adults in Malaysia. METHODS: A 100 food item FFQ focused on dietary cholesterol, total fat, saturated fat, monounsaturated fat and polyunsaturated fat intake for the past one month was developed and validated against 3-day dietary record (DR) among 151 Malay participants. Validity was assessed through the reliability and agreement of two methods. Intra-class correlation (ICC) coefficients were used to assess reliability; while regression analysis and classification into categories were used to assess agreement of the two methods. RESULTS: The mean nutrient intakes tended to be higher in FFQ compared to DR. The developed FFQ showed excellent reliability with ICC coefficients ranging from 0.92-0.98. Regression analysis demonstrated an acceptable agreement between FFQ and DR for total fat and different types of fat intakes. There were a relatively high proportion of subjects being correctly classified (into same or adjacent category) and only a small number of grossly misclassification for total energy, fat, dietary cholesterol, saturated fat and unsaturated fat occurred. CONCLUSION: This FFQ is valid in assessing absolute total energy, total fat and types of fat intakes among Malay adults.