Diet-disease Relationships Research Articles

A nutrient pattern characterized by vitamin A, C, B6, potassium, and fructose is associated with reduced risk of insulin\u2010related disorders: A prospective study among participants of Tehran lipid and glucose study

BackgroundInsulin-related disorders, including insulin resistance, insulin insensitivity, and insulinemia, is considered early predictors of major chronic disease risk. Using a set of correlated nutrient as nutrient patterns to explore the diet-disease relationship has drawn more attention recently. We aimed to investigate the association of nutrient patterns and insulin markers’ changes prospectively among adults who participated in the Tehran Lipid and Glucose Study (TLGS).Methods For the present study, 995 men and women aged 30–75 years, with complete information on insulin and dietary intake in survey III TLGS, were selected and followed three years until survey IV. Dietary intakes at baseline were assessed using a valid and reliable food frequency questionnaire (FFQ). Nutrient patterns were derived using principal component analysis (PCA). We extracted five dominant patterns based on the scree plot and categorized them into quartiles. Linear regression analysis was conducted to investigate the association between Nutrient patterns and three-year insulin markers changes, including fasting insulin, HOMA-IR, and HOMA-S.ResultsThe mean (SD) age and BMI of participants (43.1 % male) were 46.2(10.9) year and 28.0(4.7) kg/m2, respectively. The median (IQR, 25, 75) of 3 years changes of insulin, HOMA-IR and HOMA-S were 0.35 (− 1.71, 2.67) mU/mL, 0.25 (− 0.28, 0.84) and − 6.60 (− 22.8, 7.76), respectively. In the fully adjusted model for potential confounders, per each quartile increment of the fifth nutrient pattern, the β coefficients (95 % CI) of changes in insulin, HOMA-IR, and HOMA-S were − 0.36 (− 0.62, − 0.10); P value = 0.007, -0.10 (-0.19, -0.01); P value = 0.022, and 1.92 (0.18, 3.66); P value = 0.030, respectively. There were no significant association between other nutrient patterns and insulin related indices.ConclusionsPresent study showed that high adherence to a nutrient pattern rich in vitamin A, vitamin C, pyridoxine, potassium, and fructose is inversely associated with 3-years changes in insulin, HOMA-IR, and directly associated with HOMA-S.

Dietary exposures in childhood and adulthood and cardiometabolic outcomes: a systematic scoping review.

Associations between diet and cardiometabolic outcomes are often based on a single measurement of diet in adulthood. Dietary exposures in childhood are thought to influence cardiometabolic disease development and individuals' diets can change over time, therefore dietary exposure in childhood and over long periods are both important to consider. This scoping review aimed to identify and characterise the literature on associations between diet measured in both childhood and adulthood and cardiometabolic outcomes. Seven databases were searched; eligible evidence sources were original analyses published as a journal article in English. Exposures included measures of dietary intake, diet quality and eating behaviours measured in both childhood and adulthood with at least five years between first and last measurements. Cardiometabolic outcomes included measures of anthropometry, biochemistry, vascular structure/function and disease states/scores. We identified 37 eligible articles from nine cohort studies. Dietary exposures were measured between two and eight times and most often assessed by food frequency questionnaire or diet history. The dietary exposures most frequently examined were protein, fat, carbohydrate, fruit, vegetables, sugar-sweetened beverages and breakfast. Cardiometabolic outcomes were predominantly based on risk markers. Authors utilised a variety of analytical approaches to transform and analyse repeated measures of diet, providing insights relevant to different lifespan nutrition concepts. The literature on associations between diet in childhood and adulthood and cardiometabolic outcomes is limited, but such studies have great potential to extend our knowledge in ways only possible with repeated measures of diet over time. Further research is needed to develop the evidence base for diet-disease relationships from a life course perspective, accounting for diet in both childhood and adulthood.

Exploration of the Principal Component Analysis (PCA) Approach in Synthesizing the Diet Quality of the Malaysian Population.

(1) Background: One of the most main dietary assessments is through a posteriori application. Although extensive research has incorporated dietary assessment of a population through a posteriori application, this study is the first to examine the Malaysian population and use an a posteriori method and principal component analysis (PCA) to assess the dietary patterns of the Malaysian population. The correlation between all dietary patterns derived via PCA and selected nutrient intake were determined in this sample of study; (2) Methods: A total of 3063 respondents (18 to 59 years old) covering Peninsular Malaysia, Sabah, and Sarawak, participated in this study. PCA was applied on the food frequency questionnaire collected from the respondents, and descriptive statistics and PCA were performed using SPSS version 21; (3) Results: Six patterns were identified: “traditional”, “ prudent”, “ modern”, “western”, “Chinese”, and “combination” diets. All together, these six patterns were able to explain 45.9% of the total variability. Few components derived from the factor loadings showed positive association with several nutrient markers. The traditional dietary pattern showed a moderate, positive correlation with total protein and total sugar intake, there was a significant moderate correlation between the prudent dietary pattern and dietary fibre, and there was a moderate positive association between the Chinese dietary pattern and total energy; and (4) Conclusions: The exploration of the PCA approach above may provide justification for assessment of dietary patterns rather than reliance on single nutrients or foods to identify potential connections to overall nutritional wellbeing as well as to explore the diet–disease relationship. However, study of pattern analysis must be conducted among the Malaysian population to produce validity and reproducibility for this dietary approach in light of the numerous methodological issues that arise when performing PCA.

Diet Quality, Saturated Fat and Metabolic Syndrome.

Indices reflecting overall diet quality are used globally in research to predict the risk of various diseases and metabolic disorders such as metabolic syndrome (MetS). Such indices are built to measure adherence to current dietary guidelines or to best assess the diet–disease relationship. Although mostly food-based, dietary guidelines often include recommendations to limit saturated fatty acid (SFA) intake in order to prevent cardiovascular diseases. However, not all diet quality indices consider SFA in their definition of diet quality. Additionally, the relationship between SFA consumption and the development of MetS remains unclear. The purpose of this short review was to explore the association between MetS and various diet quality indices and dietary patterns, with a focus on how SFA contributes to these associations.

Demographic, Behavioural and Anthropometric Correlates of Food Liking: A Cross-sectional Analysis of Young Adults.

The degree to which foods are liked or disliked is associated with dietary intake and health behaviours. However, most food liking research has focused on single foods and nutrients and few studies have examined associations with demographics and health behaviours. Thus, this study aimed to investigate the association between food liking and socio-demographics, health behaviours, diet quality and body mass index (BMI) in a sample of young Australian adults. Data from 1728 undergraduate students (21.8 (standard deviation [SD] 6.0) years; 76% female) were used. Food liking scores and a diet quality index (Dietary Guideline Index, DGI) were estimated from a Food Liking Questionnaire and Food Frequency Questionnaire (FFQ), respectively. Multivariate linear regression analyses were used to assess the association between food liking and correlates. Young adults with higher liking for encouraged core foods were older, female, did their own food shopping, consumed less packaged foods and had better diet quality. Higher liking for discretionary foods and beverages was associated with less healthy behaviours, such as smoking, higher BMI and lower diet quality. These results suggest that food liking measures may offer an appropriate methodology for understanding influences on young adults’ food choices, adding to the body of literature investigating the potential for food liking scores to assess diet–disease relationships.

Development, validation and utilisation of dish-based dietary assessment tools: a scoping review.

To summarise the existing evidence of development, validation and current status of utilisation of dish-based dietary assessment tools. Scoping review. Systematic search using PubMed and Web of Science. We identified twelve tools from seventy-four eligible publications. They were developed for Koreans (n 4), Bangladeshis (n 2), Iranians (n 1), Indians/Malays/Chinese (n 1), Japanese (n 3) and Chinese Americans (n 1). Most tools (10/12) were composed of a dish-based FFQ. Although the development process of a dish list varied among the tools, six studies classified mixed dishes based on the similarity of their characteristics such as food ingredients and cooking methods. Tools were validated against self-reported dietary information (n 9) and concentration biomarkers (n 1). In the eight studies assessing the differences between the tool and a reference, the mean (or median) intake of energy significantly differed in five studies, and 26-83 % of nutrients significantly differed in eight studies. Correlation coefficients for energy ranged from 0·15 to 0·87 across the thirteen studies, and the median correlation coefficients for nutrients ranged from 0·12 to 0·77. Dish-based dietary assessment tools were used in fifty-nine studies mainly to assess diet-disease relationships in target populations. Dish-based dietary assessment tools have exclusively been developed and used for Asian-origin populations. Further validation studies, particularly biomarker-based studies, are needed to assess the applicability of tools.

Diet-disease relationships: Recent advances in nutritional epidemiology

Nutritional epidemiology currently studies the diet-disease relationships. In order to evaluate these associations, an accurate estimation of nutritional exposure is essential. Traditional dietary questionnaires are being complemented with the measurement of nutritional biomarkers. New methodologies, including the use of new dietary assessments, metabolomics for increasing the quantity and quality of biomarkers, and statistical approaches to combine both techniques, are required to move forward this field. In this review, we have selected five of the more relevant accomplishments in this field as examples of the importance of dietary factors in the prevention of non-communicable diseases. This theoretical knowledge needs to be finally translated by public health experts into dietary recommendations to the general population.

Traditional Self-Reported Dietary Instruments Are Prone to Inaccuracies and New Approaches Are Needed.

Background: Diet is a modifiable behavior that influences an individual's health. Because of this, diet assessment is an important component of public health surveillance, evaluating response to community health interventions, and monitoring individual compliance to medical interventions. Diet assessments are usually performed using one of three basic methods: diet recall, diet diaries, or food frequency questionnaires. Although these three assessment instruments have displayed a strong agreement between themselves, when reported intake is compared with intake measured using quantitative nutrient biomarkers, investigators have identified systematic misreporting errors for all three of these self-reported dietary instruments.Aims: This work aims to summarize the state of knowledge regarding misreporting and why it impedes diet–health research and to introduce advances in the collection and the treatment of dietary data.Methods: This work reviews and summarizes published data on misreporting and the recent efforts to reduce such errors.Results: The evidence demonstrates a strong and consistent systematic underreporting of energy intake (EIn) across adults and children studies. Underreporting of EIn has been found to increase with body mass index (BMI), and the differences between macronutrient reports indicate that not all foods are underreported equally. Protein is least underreported, but which specific foods are commonly underreported are not known.Conclusions: Because energy underreporting varies as a function of BMI, self-reported EIn should not be used for the study of energy balance in the study of obesity. The between-individual variability in the underreporting of self-reported intake of energy and other nutrients attenuates diet–disease relationships. Recent efforts to correct for underreporting have reduced misreporting of diet outcomes, but improvements have been incremental in nature and more research is needed to validate and extend these efforts.

Identification of an Obesogenic Dietary Pattern Using Partial Least Squares in a Nationally-Representative Sample of Canadian Adults

Abstract Objectives Hybrid methods of dietary patterns analysis have emerged as a unique and informative way to study diet-disease relationships in nutritional epidemiology research. The objectives of this research were to identify an obesogenic dietary pattern using weighted PLS in nationally-representative Canadian survey data, and to identify key foods and/or beverages associated with the defined obesogenic pattern. Methods Data from one 24-hr dietary recall data from the cross-sectional Canadian Community Health Survey-Nutrition (CCHS) 2015 (n = 12,110 adults) were used. Weighed partial least squares (wPLS) was used to identify an obesogenic dietary pattern from 40 standardized food and/or beverage categories using the variables energy density, fibre density, and total fat as outcomes. The association between the derived dietary pattern and likelihood of obesity was examined using weighted multivariate logistic regression. Key dietary components highly associated with the derived pattern were identified. Results Compared to quartile one (i.e., those least adherent to an obesogenic dietary pattern), those in quartile four had a 2.40-fold increased odds of being obese (OR = 2.40, 95% CI = 1.91, 3.02, P-trend < 0.0001) with a monotonically increasing trend. Using a factor loading significance cut-off of ≥|0.17|, three food/beverage categories loaded positively for the derived obesogenic dietary pattern: fast food, carbonated drinks and salty snacks. Seven food/beverage categories loaded negatively (i.e., in the protective direction): consumption of whole fruits, orange vegetables, “other” vegetables (including vegetable juice), whole grains, dark green vegetables, legumes and soy, and pasta and rice. Conclusions This study pinpoints key dietary components that are associated with obesity and consumed among a nationally-representative sample of Canadians adults. Compared to a similarly-defined obesogenic diet identified by our research group in 2004, the top contributors to a Canadian-specific obesogenic diet in 2015 have remained consistent. This evidence may aid in developing targeted policies and dietary interventions for obesity and chronic disease prevention. Funding Sources Supported by grants from the Burroughs Wellcome Fund Innovation in Regulatory Science Award and the Canadian Institutes of Health Research.

Age-and Sex-Specific Analyses of Diet Quality and 4-Year Weight Change in Nonobese Adults Show Stronger Associations in Young Adulthood

Background:Although the general importance of diet quality in the prevention of unintentional weight gain is known, it is unknown whether its influence is age or sex dependent. Objectives:The aim of this study was to investigate whether the strength of the association between diet quality and 4-y weight change was modified by age and sex. Methods:From the Dutch population-based Lifelines Cohort, 85,618 nonobese adult participants (age 18–93 y), recruited between 2006 and 2013, were included in the study. At baseline, diet was assessed with a 110-item food-frequency questionnaire. The Lifelines Diet Score, based on international evidence for diet-disease relations at the food group level, was calculated to assess diet quality. For analyses, the score was divided in quintiles (Qs). Body weight was objectively measured at baseline and after a median follow-up of 44 mo (25th–75th percentile: 35–51 mo). In between, body weight was self-reported twice. Linear mixed models were used to investigate the association between diet quality and weight change by sex and in 6 age categories (18–29, 30–39, 40–49, 50–59, 60–69, and ≥70 y). Results:Mean 4-y weight change decreased over age categories. Confounder-adjusted linear mixed models showed that the association between diet quality and weight change was modified by sex (P-interaction = 0.001). In women,the association was also modified by age (P-interaction = 0.001). Poor diet quality was most strongly associated withweight gain in the youngest men [Q1 compared with Q5: +0.33 kg/y (95% CI: 0.10, 0.56)] and women [+0.22 kg/y (95%CI: 0.07, 0.37)]. In contrast, in women aged ≥70 y, poor diet quality was associated with greater weight loss [–0.44 kg/y(95% CI: –0.84, –0.05)] Conclusions:Poor diet quality was related to higher weight gain, especially in young adults. Oppositely, among women aged≥70 y, poor diet quality was related to higher weight loss. Therefore, a healthful diet is a promising target for undesirable weight changes in both directions.

Basic knowledge about healthy eating in medical graduates

Introduction: the promotion of a healthy lifestyle is an imperative need to both reduce the risk of non-communicable diseases associated with lifestyle, and prevent their progression. Objective: to evaluate the basic knowledge about healthy eating of a cohort of graduates from medical school. Method: a descriptive research was conducted through a review of the inclusion of a nutrition subject matter in the curriculum of medical schools. A food knowledge questionnaire was administered to 80 physicians at the first level of care who had graduated five years before the research. Results: the correct answers to the questionnaire obtained on average 64.96 points out of a possible score of 113. There was a weak association between scores for "diet-disease relationship" and "source of nutrition" (p = 0.016). In the curriculum of the reviewed medical schools, biochemistry courses are privileged over nutrition courses. The nutrition courses imparted in medical schools do not have a minimum of hours, and are not structured to train health promotion capabilities. The participants had low scores in all areas. Conclusions: it is necessary that nutrition courses be reconfigured to face the pandemic of non-communicable diseases and their consequences both in patients and in health systems.

Knowledge of nutrition among students in a dental teaching institution in Kerala

Introduction: Basic education about nutrition can be extremely beneficial for medical and dental professionals. It is very important that, dental students are taught about nutrition during their course of study as this will help in developing a holistic approach in treating patients. As limited literature is available regarding the nutritional knowledge among dental students, the present study was done to assess the same among students in a dental teaching institution. Materials and Methods: The awareness of dietary recommendations, knowledge of food sources and nutrients and diet–disease relationship was assessed among clinical students of a dental teaching institute in Kerala, through a 13-point self-administered questionnaire. Analysis was done based on two groups (undergraduate [UG] students and post-graduate [PG] students). Results: A total number of 140 responses were obtained. UG students comprised 31.4% while PG students comprised 68.6% of the study population. Majority (>75%) of the participants in both groups (UG and PG) felt that there is a need to consume more vegetables and fibers and less amounts of sugary and fatty foods. Among the PG students, most respondents (36%) opined that sugar contained more calories for the same weight while 34% of PG students and 44% of UG students reported that starchy food contained more calories. While more than 95% of participants associated diabetes to sugar consumption, there was a mixed response for kidney disease (47.7% in PG and 53.1% in UG; P

Association between diet quality indicators and nonalcoholic fatty liver disease: The FLiO study

AbstractIntroductionDietary components are contributing factors in the development of Nonalcoholic fatty liver disease (NAFLD). The glycaemic index (GI), glycaemic load (GL) and total antioxidant capacity (TAC) have been considered potential dietary tools influencing diet–disease relationships. The aim of this study was to evaluate associations of the dietary GI, GL, TAC and insulin resistance (IR) condition with hepatic fat in NAFLD adults.Material and methods: 112 overweight/obese adults with NAFLD (age: 50.8 ± 9 years old) were included in the trial. Dietary intake was assessed by a validated 137-item food frequency questionnaire (FFQ). Anthropometric, glycemic and lipid profiles, fatty liver quantification by magnetic resonance imaging (MRI) and IR measured by the Homeostatic Model Assessment of IR (HOMA-IR) were assessed at baseline. This study was registered as FLiO: Fatty Liver in Obesity study; NCT03183193.Results: The median of liver fat content by MRI was 6.4 (3.8–10.9) in the recruited population. Participants with higher liver fat content showed significantly increased values of glucose, insulin, HbA1c and HOMA-IR than those with lower liver fat content (p < 0.05). Correlation analyses revealed relevant positive associations of hepatic fat with GI (r = 0.17; p = 0.077) and GL (r = 0.19; p = 0.047). Also, a negative association between liver fat content and TAC (r = -0.22; p = 0.023) was found. Linear regression analyses were used to examine the associations of hepatic fat and dietary quality indicators as well as IR adjusted for potential confounders (sex, age and physical activity). The final models showed that HOMA-IR, GI, GL and TAC were able to explain between 22.4 and 22.8 % (p < 0.001) of the variability of liver fat content.DiscussionThe pathophysiology of NAFLD is thought to be associated with dietary determinants that contribute to metabolic dysregulation such as IR, ectopic liver fat deposition and hepatic damage. In accordance with other authors, we suggest that monitoring GI, GL and TAC may be useful approaches for the dietary treatment of NAFLD since they are related to hepatic fat. Additionally, it is important to highlight the essential role of IR in NAFLD as a key mediator in the development of NAFLD. Certainly, findings of the present study revealed a significant association of hepatic fat accumulation and IR.In summary, GI, GL and TAC are potential markers of diet quality, with an impact on susceptible population at hepatic risk.

Prospective associations between a food-based Indian Diet Quality Score and type 2 diabetes risk among South Indian adults (CURES-154)

Background: Asian Indians are culturally different and have diverse dietary and culinary habits. Further, there are potential biological differences in metabolism due to genetic or cultural factors. This warrants the development of a unique population-specific food-based diet score for prevention of noncommunicable disorders. Materials and Methods: Dietary intake was assessed using a validated food frequency questionnaire in 1033 adults who participated in the 10-year follow-up study of Chennai Urban Rural Epidemiological Study (CURES). The diet score was developed considering eight food groups and one major cooking oil that were either significantly associated with a higher or lower risk of incident type 2 diabetes (T2D). The foods that showed a protective effect was assigned higher scores and vice versa for foods that increased the risk of diabetes assigned the lower. We further assessed the effect of Indian Diet Quality score (IDQS) and three popular diet quality indices: the Healthy Eating Index-2015 (HEI), the Dietary Approach to Stop Hypertension (DASH), and Diabetes Diet Score (DDS) in relation to the risk of incidence of diabetes among Indian population. Results: Higher IDQS is associated with a significant lower risk of diabetes incidence; however, no such significant association was observed with diet quality indices (DASH, HEI-2015, and DDS) and diabetes incidence. This warrants the need for population-specific diet score for Indians. Conclusion: Higher IDQS was associated with a lower risk of T2D among South Indian adults. Thus, IDQS can be a suitable tool to identify the diet–disease relationship especially in a population with diverse dietary intakes.

Evaluating USA’s New Nutrition and Supplement Facts Label: Evidence from a Non-hypothetical Choice Experiment

In May 2016, the FDA published new rules for Nutrition and Supplement Facts label formats and contents, which take effect in 2019. The revised labelling is designed to help consumers make better-informed product choices in support of a healthier diet. Changes in nutrition label requirements include the prominent display of “calories per serving” and “serving size” as well as updated nutritional requirements and information reflecting contemporary scientific knowledge about diet–disease relationships. No other known study however has directly examined whether these new upcoming changes will help consumers make healthier choices. To fill this void, we conducted a non-hypothetical choice experiment on “light” and “original” strawberry yogurt products at a major public University in the USA. Using a generalized mixed logit model with a scale parameter to account for taste heterogeneity among participants, we find that the new label changes food choice behavior. Specifically, we find that the new label reduces consumer’s preferences for both original and low-fat yogurts. This finding is evident among the more health-conscious subsample. It is possible that the new label generates an “alarm” effect given the revised features on calories, added sugar and serving size, especially among those who are more nutrition and health conscious and those who use labels for nutrient information.

Biostatistical Analysis on Chronic Disease Risk

Introduction: Approximately one-third of all college students aged 18-29 were classified as overweight or obese, increasing their risk for chronic disease. Nutritional knowledge is an important first step to developing strategist to improve the food choices of college students and promote healthy lifestyle behaviors. Therefore, the purpose of this study was to determine the current nutritional knowledge of students enrolled in courses within the Human Performance and Leisure Studies (HPLS) Department at Hubei University of Technology (HBUT). Methods: Paper based surveys were used to administer the 56-question Nutritional Knowledge Questionnaire (NKQ) for students enrolled in HPLS courses in spring 2017. Results: Response rate was 65.6% (n=236). Gender distribution was equal among the surveyed students (45.3% male vs. 53.8% females). The majority reported majoring in sports science and fitness management (SSFM) (76.7%), were between 18-24 years old (86.9%) with a self-identified ethnic origin of Chinese Xinjiang person (89.8%). The average nutritional knowledge score was 49.2 +/- 9.8 or 44.8%. Knowledge of diet-disease relationship was higher in females (5.4 +/- 1.9) compared to males (4.8 +/- 2.3), p = 0.03. Conclusion: In this study, we found a need to improve nutritional knowledge in college students enrolled in select HPLS courses in the spring of 2017 at HBUT. The findings highlight a gap in nutrition education and the opportunity to develop courses or programs aimed at healthful eating for students majoring in SSFM or attending HBUT.

The Impact of a Community-Based Food Education Program on Nutrition-Related Knowledge in Middle-Aged and Older Patients with Type 2 Diabetes: Results of a Pilot Randomized Controlled Trial.

The purpose of this study was to evaluate the impact of a community-based food education program on nutrition-related knowledge in middle-aged and older patients with type 2 diabetes (T2D). Participants (n = 36; 65.9 ± 6.0 years old) were recruited in primary health care to a 9-month community-based lifestyle intervention program for patients with T2D and randomly assigned to an exercise program (control group; n = 16) or an exercise program plus a food education program (experimental group; n = 20). Nutrition-related knowledge was assessed through a modified version of the General Nutrition Knowledge Questionnaire. The increase in total nutrition-related knowledge score and sources of nutrients area score was significantly higher in the experimental group compared to the control group. No significant changes in nutrition-related knowledge were found between groups in dietary recommendations and diet-disease relationship areas, although improvements were observed. This community-based food education program, with the use of easy to implement strategies (short-duration lectures and dual-task problem solving activities during exercise), had a positive and encouraging impact on nutrition-related knowledge in middle-aged and older patients with T2D.

Qualified Health Claim Language affects Purchase Intentions for Green Tea Products in the United States.

Qualified health claims (QHC) describe diet–disease relationships and summarize the quality and strength of evidence for a claim. Companies assert that QHCs increase sales and take legal action to ensure claims reflect their interests. Yet, there is no empirical evidence that QHCs influence consumers. Using green tea as a case study, this study investigated the effects of QHCs on purchase intentions among adults 55 years and older living in the US. An online survey using a between-subjects design examined QHCs about the relationship between green tea and the reduced risk of breast and/or prostate cancer or yukichi fruit juice and the reduced risk of gastrocoridalis, a fictitious relationship. QHCs written by a green tea company generated greater perceptions of evidence for the relationship, greater confidence in green tea and cancer, and increased purchase intentions for green tea than other QHCs. Factors that mitigated the claim’s effects on purchase intentions are: Race/ethnicity; age; importance of health claims; supplement use; health; worry about health/becoming sick with cancer; worry that led to dietary change; green tea consumption; and familiarity with the green tea–cancer. Consumers who made health-related dietary change in the past year and consider health claims important indicated greater purchase intentions than others.

Reproducibility of Dietary Biomarkers in a Multiethnic Asian Population.

Dietary biomarkers allow for study of diet and disease risk relationships, but a key requirement is that these biomarkers are reproducible and reflect long-term diet. This study assesses reproducibility of selected dietary biomarkers in a multi-ethnic Asian population, and quantifies diet-disease relationship attenuation arising from use of a single biomarker measurement. Intra-class correlation coefficients (ICC) are used to evaluate the reproducibility of urinary isoflavone and enterolignan, total plasma fatty acid (FA), and serum carotenoid concentrations measured 4 months apart in adult Singapore residents (ethnic Chinese, n 59; Malay, n 46; Indian, n 56). Total carotenoid ICC is 0.75 (95% confidence interval (CI) 0.68, 0.81), ranging from 0.63 to 0.84 for individual carotenoids. FA ICC (median) is 0.74 (inter-quartile range 0.70-0.78). Total isoflavone ICC (95% CI) is 0.21 (0.06-0.35). Total enterolignan ICC is 0.42 (0.28, 0.54). Attenuation factors associated with a single time point measure ranged from 0.74 to 0.94 for carotenoids and FAs, and 0.42 to 0.70 for isoflavones and enterolignans. In a multi-ethnic Asian population, single measures of most serum carotenoids and plasma FAs likely represent habitual diet, whereas reproducibility of urinary isoflavones and enterolignans is moderate, possibly due to rapid excretion.

Reproducibility of dietary intakes of macronutrients, specific food groups, and dietary patterns in 211 050 adults in the UK Biobank study.

To detect modest associations of dietary intake with disease risk, observational studies need to be large and control for moderate measurement errors. The reproducibility of dietary intakes of macronutrients, food groups and dietary patterns (vegetarian and Mediterranean) was assessed in adults in the UK Biobank study on up to five occasions using a web-based 24-h dietary assessment (n 211 050), and using short FFQ recorded at baseline (n 502 655) and after 4 years (n 20 346). When the means of two 24-h assessments were used, the intra-class correlation coefficients (ICC) for macronutrients varied from 0·63 for alcohol to 0·36 for polyunsaturated fat. The ICC for food groups also varied from 0·68 for fruit to 0·18 for fish. The ICC for the FFQ varied from 0·66 for meat and fruit to 0·48 for bread and cereals. The reproducibility was higher for vegetarian status (κ > 0·80) than for the Mediterranean dietary pattern (ICC = 0·45). Overall, the reproducibility of pairs of 24-h dietary assessments and single FFQ used in the UK Biobank were comparable with results of previous prospective studies using conventional methods. Analyses of diet-disease relationships need to correct for both measurement error and within-person variability in dietary intake in order to reliably assess any such associations with disease in the UK Biobank.