Diet is a major lifestyle-related risk factor of various chronic diseases. Dietary intake can be assessed by subjective report and objective observation. Subjective assessment is possible using open-ended surveys such as dietary recalls or records, or using closed-ended surveys including food frequency questionnaires. Each method has inherent strengths and limitations. Continued efforts to improve the accuracy of dietary intake assessment and enhance its feasibility in epidemiological studies have been made. This article reviews common dietary assessment methods and their feasibility in epidemiological studies.

https://www.e-epih.org/upload/pdf/epih-36-e2014009.pdf

Dietary assessment methods in epidemiologic studies.

Validation and reproducibility of food frequency questionnaire for Korean genome epidemiologic study

Validation and reproducibility of food frequency questionnaire for Korean genome epidemiologic study.

Evidence for a major role of genetic factors in the determination of body mass index (BMI) comes from studies of related individuals. However, heritability estimates for BMI vary widely between studies and the reasons for this remain unclear. While some variation is natural due to differences between populations and settings, study design factors may also explain some of the heterogeneity. We performed a systematic review that identified eighty-eight independent estimates of BMI heritability from twin studies (total 140,525 twins) and twenty-seven estimates from family studies (42,968 family members). BMI heritability estimates from twin studies ranged from 0.47 to 0.90 (5th/50th/95th centiles: 0.58/0.75/0.87) and were generally higher than those from family studies (range: 0.24-0.81; 5th/50th/95th centiles: 0.25/0.46/0.68). Meta-regression of the results from twin studies showed that BMI heritability estimates were 0.07 (P=0.001) higher in children than in adults; estimates increased with mean age among childhood studies (+0.012 per year, P=0.002), but decreased with mean age in adult studies (-0.002 per year, P=0.002). Heritability estimates derived from AE twin models (which assume no contribution of shared environment) were 0.12 higher than those from ACE models (P<0.001), whilst lower estimates were associated with self-reported versus DNA-based determination of zygosity (-0.04, P=0.02), and with self-reported versus measured BMI (-0.05, P=0.03). Together, the above factors explained 47% of the heterogeneity in estimates of BMI heritability from twin studies. In summary, while some variation in BMI heritability is expected due to population-level differences, study design factors explained nearly half the heterogeneity reported in twin studies. The genetic contribution to BMI appears to vary with age and may have a greater influence during childhood than adult life.

Variability in the Heritability of Body Mass Index: A Systematic Review and Meta-Regression

The food frequency questionnaire (FFQ) has been used as an important dietary assessment tool in epidemiologic studies, but the usefulness of the FFQ has been debated in recent years. This study was performed to evaluate the relative validities of 3-day food records and the semi-quantitative FFQ. A total of 124 subjects finished 3-day food records (FRs) during each of the four seasons, as well as the FFQ from December 2002 to May 2004. The FFQ was a food based semi-quantitative FFQ including 103 items. Three-day FRs from each season and a randomly selected season were compared with the remaining 9-day FRs. The remaining 9-day FRs, as a reference measurement, were also compared with the FFQ. Pearson’s correlation coefficients between the 3-day FRs and the 9-day FRs were between 0.14 and 0.56. Pearson’s correlation coefficients between the FFQ and the 9-day FRs ranged between 0.07 and 0.41. Average proportions of classification into the same quartiles, adjacent quartiles, and distant quartiles between the 3-day FRs and the 9-day FRs were 35.8%, 40.5%, and 5.2%, respectively. On average, the proportions of classification into the same quartiles, adjacent quartiles, and distant quartiles between the FFQ and the 9-day FRs were 31.1%, 39.4%, and 6.9%, respectively. Three-day FRs showed higher correlations and higher agreement proportions of quartile classification with the 9-day FRs than did the FFQ, but both relative validities of 3-day FRs and the FFQ appear to be acceptable as dietary assessment tools. Further studies for validating food intake by reliable biomarkers are necessary.

/pdf/relative-validities-of-3-day-food-records-and-the-food-238cn5dmjo.pdf

Relative validities of 3-day food records and the food frequency questionnaire

Spousal pairs permit assessment of determinants of diseases related to environment, because they share the same lifestyle and environment. The authors reviewed spouses' concordance for the major coronary risk factors. A search of the MEDLINE, PubMed, and EMBASE databases was performed. Seventy-one papers were selected for a total of 207 cohorts of pairs and 424,613 correlations in more than 100,000 couples. The most strongly correlated within-pairs factors were smoking and body mass index, with overall correlations of 0.23 (95% confidence interval: 0.12, 0.36) and 0.15 (95% confidence interval: 0.05, 0.25), respectively. Statistically significant positive correlations were also found for diastolic blood pressure, triglycerides, total and low density lipoprotein cholesterol, weight, and the waist/hip ratio. The overall odds ratios for concordance in hypertension, smoking, diabetes, and obesity were all statistically significant, ranging from 1.16 to 3.25. Assortative mating influenced concordance for blood pressure, smoking, glucose, low density lipoprotein cholesterol, weight, body mass index, and waist circumference. This systematic review shows a statistically significant positive spousal concordance for the majority of main coronary risk factors. However, the strength of the concordance was markedly different among factors and appeared to be quite modest for all of them. Interventions to reduce cardiovascular risk factors should be addressed jointly to both members of a marital couple.

/pdf/spousal-concordance-for-major-coronary-risk-factors-a-24f3amammx.pdf

Spousal concordance for major coronary risk factors: a systematic review and meta-analysis.

https://www.koreascience.or.kr:443/article/JAKO200211921171107.pdf

A Study on Validity of a Semi-Quantitative Food Frequency Questionnaire for Korean Adults

The goal of this study was to describe the overall genetic contribution of phenotypic variation to cardiovascular disease The study population included 7,589 family members of 1,891 families, derived from Korean Medical Insurance Corporation The risk factors considered were systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), and high serum cholesterol The levels of cardiovascular disease risk factors were adjusted for age, gender, smoking and alcohol drinking Heritability was estimated from the slope of the line linear regression of offspring on mid-parent All risk factors showed positive familial correlations, and correlations were generally lower for spouses than for parent- offspring pairs Spouse correlations showed increasing patterns with age Parents-offspring correlations showed little variation with age, suggesting that the observed correlations with CVD risk factors were primarily due to genetic influences rather than environmental effects Estimated heritabilities were 26% for BMI, 26% for high serum cholesterol, 19% for SBP, and 9% for DBP These results highlight the importance of considering genetic factors in studies of cardiovascular risk factors

Mi Yang Kim

Papers

A Study on Validity of a Semi-Quantitative Food Frequency Questionnaire for Korean Adults

Familial correlation and heritability for cardiovascular risk factors.