Sources of variability in dietary intake in two distinct regions of rural India: implications for nutrition study design and interpretation

Assessing the Diets of Young Children and Adolescents in India: Challenges and Opportunities

Sustainably addressing the crisis of undernutrition for children and adolescents in underserved and resource-limited communities will require, among other investments, interventions aimed at optimizing the diets of these vulnerable populations. However, to date, there are substantial global gaps in the collection of dietary data in children and adolescents. This review article summarizes the challenges and opportunities in assessing diet among children and adolescents in India. National surveys in India identify the scale of the triple burden of malnutrition (undernutrition, micronutrient deficiencies and overnutrition) in children and adolescents and assess key nutrition and food security indicators for making informed policy decisions. However, national surveys do not collect data on diet, instead relying on anthropometry, biomarkers of micronutrient deficiencies, and summary measures of diet, such as the WHO infant and young child feeding summary indicators. Sub-national surveys and the scientific literature thus fill important gaps in describing the nutrient intakes of children and adolescents in India; however large gaps remain. Future research can be improved by investments in infrastructure to streamline the assessment of diet in India. The current challenges confronting the collection and analysis of high-quality dietary data occur in both the data collection and data analysis phases. Common methods for assessing diets in low-resource settings-such as 24 h recalls and food frequency questionnaires are particularly challenging to implement well in young children and adolescents due to motivation and memory issues in young respondents. Additionally, there are challenges with parental recall including children having multiple caretakers and meals outside the home. Furthermore, analysis of dietary data is hindered by the lack of affordable, accessible software for dietary data analysis relevant to the diversity in Indian diets. New technologies can address some of the challenges in dietary data collection and analysis, but to date, there are no platforms designed for population-level dietary assessment in India. Public and private sector investment in dietary assessment, as well as collaboration of researchers and the creation of open-source platforms for the sharing of data inputs (local food lists, recipe databases, etc.) will be essential to build infrastructure to better understand the diets of children and adolescents in India and improve dietary interventions in these target groups.

Lean Mass Improvement from Nutrition Education and Protein Supplementation among Rural Indian Women Living with HIV/AIDS: Results from Cluster Randomized Factorial Trial at 18-Month Follow-Up

Loss of lean muscle mass impairs immunity and increases mortality risk among individuals with HIV/AIDS. We evaluated the relative contributions of protein supplementation and nutrition education on body composition among 600 women living with HIV/AIDS in rural Andhra Pradesh, India. We conducted a cluster randomized controlled 2 × 2 factorial trial lasting six months with follow up at twelve and eighteen months. Interventions occurred in the Nellore and Prakasam regions of Andhra Pradesh by trained village women, ASHA (Accredited Social Health Activists), and included: (1) the usual supportive care from ASHA (UC); (2) UC plus nutrition education (NE); (3) UC plus nutritional protein supplementation (NS); (4) combined UC plus NE plus NS. A Bioimpedance Analyzer Model 310e measured body composition. SAS 9.4 analyzed all data. Mixed models using repeated measures evaluated lean mass change from baseline as primary and fat weight and total weight as secondary outcomes. Lean mass change was significantly associated with NS (p = 0.0001), NE (p = 0.0001), and combined NS plus NE (p = 0.0001), with similar associations for secondary outcomes. Stronger associations for total weight were observed with greater ART adherence. Nutritional interventions may improve physiologic response to HIV. Significant increases in lean mass resulted from independent and combined protein supplementation and nutrition education.

Within-Person Variation in Nutrient Intakes across Populations and Settings: Implications for the Use of External Estimates in Modeling Usual Nutrient Intake Distributions

Determining the proportion of a population at risk of inadequate or excessive nutrient intake is a crucial step in planning and managing nutrition intervention programs. Multiple days of 24-h dietary intake data per subject allow for adjustment of modeled usual nutrient intake distributions for the proportion of total variance in intake attributable to within-individual variation (WIV:total). When only single-day dietary data are available, an external adjustment factor can be used; however, WIV:total may vary by population, and use of incorrect WIV:total ratios may influence the accuracy of prevalence estimates and subsequent program impacts. WIV:total values were compiled from publications and from reanalyses of existing datasets to describe variation in WIV:total across populations and settings. The potential impact of variation in external WIV:total on estimates of prevalence of inadequacy was assessed through simulation analyses using the National Cancer Institute 1-d method. WIV:total values were extracted from 40 publications from 24 countries, and additional values were calculated from 15 datasets from 12 nations. Wide variation in WIV:total (from 0.02 to 1.00) was observed in publications and reanalyses. Few patterns by population characteristics were apparent, but WIV:total varied by age in children (< vs. >1 y) and between rural and urban settings. Simulation analyses indicated that estimates of the prevalence of inadequate intake are sensitive to the selected ratio in some cases. Selection of an external WIV:total estimate should consider comparability between the reference and primary studies with regard to population characteristics, study design, and statistical methods. Given wide variation in observed ratios with few discernible patterns, the collection of ≥2 days of intake data in at least a representative subsample in population dietary studies is strongly encouraged. In the case of single-day dietary studies, sensitivity analyses are recommended to determine the robustness of prevalence estimates to changes in the variance ratio.

The impact of a randomized dietary and physical activity intervention on chronic inflammation among obese African-American women

Lifestyle interventions may reduce inflammation and lower breast cancer (BrCa) risk. This randomized trial assessed the impact of the Sistas Inspiring Sistas Through Activity and Support (SISTAS) study on plasma C-reactive protein (CRP), interleukin-6 (IL-6) and Dietary Inflammatory Index (DII). This unblinded, dietary and physical activity trial was implemented in 337 obese (body mass index [BMI] ≥30 kg/m²) African American (AA) women recruited between 2011 and 2015 in South Carolina through a community-based participatory approach with measurements at baseline, 3 months, and 12 months. Participants were randomized into either intervention (n = 176) or wait-list control group (n = 161). Linear mixed-effect models were used for analyses of CRP and IL-6. Baseline CRP was significantly higher in those with greater obesity, body fat percentage, and waist circumference (all p <.01). No difference was observed between groups for CRP or IL-6 at 3 or 12 months; however, improvements in diet were observed in the intervention group compared to the control group (p = .02) at 3 months but were not sustained at 12 months. Although the intervention was not successful at reducing levels of CRP or IL-6, a significant decrease was observed in DII score for the intervention group, indicating short-term positive dietary change.

The Evaluation and Use of a Food Frequency Questionnaire Among the Population in Trivandrum, South Kerala, India

Dietary record tools such as food frequency questionnaire (FFQ) and food diaries (FD) are the most commonly used choices for assessing dietary intakes in most large-scale epidemiological studies. The authors developed a self-administered 360-item food frequency questionnaire (FFQ) to assess dietary intakes amongst a population-based cohort in South Kerala. In the validation study (n = 460), the data were collected using FFQs that were administered on three different occasions which were then compared to 7-day food records. The intake of foods and nutrients was higher as determined by the FFQ than that assessed using food records. Spearman correlations for macro-nutrients ranged from 0.72 for protein to 0.61 for carbohydrates and for micronutrients, from 0.71 for vitamin B6 to 0.34 for magnesium. The correlation was improved with energy-adjusted nutrient intakes. On average, the exact agreement for the macronutrients ranged from 48.2% to 57.1%, and that for micronutrients ranged from 66.7% to 41.9%, with the median percentage of 49.58%. The authors conclude that the FFQ has an acceptable reproducibility, however, there was a systematic trend towards higher estimates with the FFQ for most nutrients compared to the FD records.

Long-Term Effectiveness of a Lifestyle Intervention: A Pragmatic Community Trial to Prevent Metabolic Syndrome

INTRODUCTION

The purpose of this study is to evaluate the long-term effectiveness of a community-based lifestyle education on primary prevention of metabolic syndrome in a middle-income country.

STUDY DESIGN

This study followed 3,180 individuals free of metabolic syndrome who were under the coverage of three health centers in Tehran from 1999 until 2015. They were undergoing triennial examinations resulting in four re-exams. People in one of three areas received interventions consisting of family-, school-, and community-based educational programs, including a face-to-face educational session at baseline. Data were analyzed considering the incidence of metabolic syndrome at each re-exam and also repeated-measure analysis including all re-exams together. Weighting was considered to correct selection bias because of loss to follow-up. Data were analyzed in 2017.

RESULTS

After 3 years, 149 of 852 participants in the intervention and 471 of 2,328 people in control area developed metabolic syndrome at first re-exam resulting in a RR of 0.78 (95% CI=0.67, 0.92). The difference between groups remained unchanged up to the 6-year follow-up (RR=0.79, 95% CI=0.66, 0.93, at second re-exam), but disappeared during the third and fourth re-exams (RR=1.04, 95% CI=0.91, 1.18 and RR=1.03, 95% CI=0.91, 1.16, respectively). Marginal models for longitudinal data showed a significant interaction between intervention and time of re-exams. Further analyses showed that the effect of the intervention might have been rooted in improvement of lipid profile and glucose level.

CONCLUSIONS

In a middle-income country, face-to-face educational sessions followed by a long-term maintenance community-level educational program could reduce the risk of metabolic syndrome for up to 6 years. A booster face-to-face session is recommended to retain this preventive effect.

TRIAL REGISTRATION

This study is registered at Iran Registry for Clinical Trials (http://irct.ir) IRCT138705301058N1.

Dietary inflammatory index is positively associated with serum high-sensitivity C-reactive protein in a Korean adult population

OBJECTIVE

To our knowledge, only a few studies have explored the relationship between the inflammatory potential of diet and serum inflammatory markers in Korean adults. The likely novel aim of this study was to examine the association between the dietary inflammatory index (DII) and serum high-sensitivity C-reactive protein (hs-CRP) in a Korean adult population.

METHODS

A cross-sectional study was conducted using the data set from the Korea National Health and Nutrition Examination Survey (KNHANES) 2015. Korean adults ≥19 y of age with hs-CRP values were included in this study. After excluding individuals with missing variables for covariates, the final analytic sample for the study was 3014 adults (1295 men and 1719 women). DII scores were calculated from a 1-d 24-h dietary recall, and hs-CRP was measured using the immunoturbidimetric method. Multivariable logistic regression analyses were performed to calculate adjusted odds ratios (AORs) and 95% confidence intervals (CIs) to test the effect of the DII score on serum hs-CRP as dichotomous (>2 versus ≤2 mg/L).

RESULTS

A significant association was observed between increasing DII scores and elevated hs-CRP. Korean adults in the highest quintile of the DII (indicating the most proinflammatory diet), compared with the lowest quintile of the DII (indicating the most anti-inflammatory diet), had increased odds of having elevated hs-CRP concentrations (>2 mg/L; AOR, 1.70; 95% CI, 1.07-2.69; P_trend < 0.0001) after controlling for age, sex, education, marital status, alcohol consumption, smoking status, body mass index, high-density lipoprotein cholesterol, and physical activity.

CONCLUSION

Higher DII scores were positively associated with elevated hs-CRP levels in Korean adults. Because inflammation affects the risk for cancer, cardiovascular disease, and other inflammation-related conditions, future studies are warranted to examine the effect of the DII on other inflammatory biomarkers and chronic disease outcomes among the Korean population.

Sistas Inspiring Sistas Through Activity and Support (SISTAS): Study Design and Demographics of Participants

Introduction

Recruiting racial, ethnic, and other underserved minorities into conventional clinic-based and other trials is known to be challenging. The Sistas Inspiring Sistas Through Activity and Support (SISTAS) Program was a one-year randomized controlled trial (RCT) to promote physical activity and healthy eating among AA women in SC to reduce inflammatory biomarkers, which are linked to increased breast cancer (BrCa) risk and mortality. This study describes the development, recruitment, and implementation of the SISTAS clinical trial and provides baseline characteristics of the study participants.

Methods

SISTAS was developed using community-based participatory research (CBPR) approaches. At baseline, study participants completed assessments and underwent clinical measurements and blood draws to measure C-reactive protein (CRP) and interleukin-6 (IL-6). Participants randomized to the intervention received 12 weekly classes followed by nine monthly booster sessions. Post-intervention measurements were assessed at 12-week and 12-month follow-ups.

Results

We recruited a total of 337 women who tended to: be middle-aged (mean age 48.2 years); have some college education; be employed full-time; have Medicare as their primary insurance; be non-smokers; and perceive their personal health as good. On average, the women were pre-hypertensive at baseline (mean systolic blood pressure = 133.9 mm Hg; mean diastolic blood pressure = 84.0 mm Hg) and morbidly obese (mean BMI >40.0 kg/m²); the mean fat mass and fat-free mass among participants were 106.4 lb and 121.0 lb, respectively.

Conclusion

The SISTAS RCT addresses some of the gaps in the literature with respect to CBPR interventions targeting AA women, such as implementing diet and physical activity in CBPR-based studies to decrease BrCa risk.

Inflammatory potential of diet and all-cause, cardiovascular, and cancer mortality in National Health and Nutrition Examination Survey III Study

BACKGROUND

Various dietary components have been studied in relation to overall mortality; however, little is known about the relationship between the inflammatory potential of overall diet and mortality.

MATERIALS AND METHODS

We examined the association between the dietary inflammatory index (DII) and mortality in the National Health and Nutrition Examination Survey III follow-up study. The DII was computed from baseline dietary intake assessed using 24-h dietary recalls (1988-1994). Mortality was determined from the National Death Index records through 2006. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95 % confidence interval (95 % CI). During the follow-up, 2795 deaths were identified, including 1233 due to cardiovascular disease (CVD), and 615 due to cancer, 158 of which were due to digestive-tract cancers.

RESULTS

Multivariate Cox proportional hazards regression analyses, adjusting for age, race, diabetes status, hypertension, physical activity, body mass index, poverty index, and smoking, revealed positive associations between higher DII scores and mortality. Comparing subjects in DII tertile 3 versus tertile 1, significant associations were noted for all-cause mortality (HR_Tertile3vs1 1.34; 95 % CI 1.19-1.51, P _trend < 0.0001), CVD mortality (HR_Tertile3vs1 1.46; 95 % CI 1.18-1.81, P _trend = 0.0006), cancer mortality (HR_Tertile3vs1 1.46; 95 % CI 1.10-1.96, P _trend = 0.01), and digestive-tract cancer mortality (HR_Tertile3vs1 2.10; 95 % CI 1.15-3.84, P _trend = 0.03).

CONCLUSION

These results indicate that a pro-inflammatory diet, as indicated by higher DII scores, was associated with higher risk of all-cause, CVD, and cancer mortality.

Considering the value of dietary assessment data in informing nutrition-related health policy

Dietary assessment has long been known to be challenged by measurement error. A substantial amount of literature on methods for determining the effects of error on causal inference has accumulated over the past decades. These methods have unrealized potential for improving the validity of data collected for research studies and national nutritional surveillance, primarily through the NHANES. Recently, the validity of dietary data has been called into question. Arguments against using dietary data to assess diet-health relations or to inform the nutrition policy debate are subject to flaws that fall into 2 broad areas: 1) ignorance or misunderstanding of methodologic issues; and 2) faulty logic in drawing inferences. Nine specific issues are identified in these arguments, indicating insufficient grasp of the methods used for assessing diet and designing nutritional epidemiologic studies. These include a narrow operationalization of validity, failure to properly account for sources of error, and large, unsubstantiated jumps to policy implications. Recent attacks on the inadequacy of 24-h recall-derived data from the NHANES are uninformative regarding effects on estimating risk of health outcomes and on inferences to inform the diet-related health policy debate. Despite errors, for many purposes and in many contexts, these dietary data have proven to be useful in addressing important research and policy questions. Similarly, structured instruments, such as the food frequency questionnaire, which is the mainstay of epidemiologic literature, can provide useful data when errors are measured and considered in analyses.

Development of a field-friendly automated dietary assessment tool and nutrient database for India

Studies of diet and disease risk in India and among other Asian-Indian populations are hindered by the need for a comprehensive dietary assessment tool to capture data on the wide variety of food and nutrient intakes across different regions and ethnic groups. The nutritional component of the India Health Study, a multicentre pilot cohort study, included 3908 men and women, aged 35-69 years, residing in three regions of India (New Delhi in the north, Mumbai in the west and Trivandrum in the south). We developed a computer-based, interviewer-administered dietary assessment software known as the 'NINA-DISH (New Interactive Nutrition Assistant - Diet in India Study of Health)', which consisted of four sections: (1) a diet history questionnaire with defined questions on frequency and portion size; (2) an open-ended section for each mealtime; (3) a food-preparer questionnaire; (4) a 24 h dietary recall. Using the preferred meal-based approach, frequency of intake and portion size were recorded and linked to a nutrient database that we developed and modified from a set of existing international databases containing data on Indian foods and recipes. The NINA-DISH software was designed to be easily adaptable and was well accepted by the interviewers and participants in the field. A predominant three-meal eating pattern emerged; however, patterns in the number of foods reported and the primary contributors to macro- and micronutrient intakes differed by region and demographic factors. The newly developed NINA-DISH software provides a much-needed tool for measuring diet and nutrient profiles across the diverse populations of India with the potential for application in other South Asian populations living throughout the world.

Sources of variation in nutrient intake and the number of days to assess usual intake among men and women in the Seoul metropolitan area, Korea

Sources of variation in nutrient intake have been examined for Western diets, but little is known about the sources of variation and their differences by age and sex among Koreans. We examined sources of variation in nutrient intake and calculated the number of days needed to estimate usual intake using 12 d of dietary records (DR). To this end, four 3 d DR including two weekdays and one weekend day were collected throughout four seasons of 1 year from 178 male and 236 female adults aged 20-65 years residing in Seoul, Korea. The sources of variation were estimated using the random-effects model, and the variation ratio (within-individual:between-individual) was calculated to determine a desirable number of days. Variations attributable to the day of the week, recording sequence and seasonality were generally small, although the degree of variation differed by sex and age (20-45 years and 46-65 years). The correlation coefficient between the true intake and the observed intake (r) increased with additional DR days, reaching 0·7 at 3-4 d and 0·8 at 6-7 d. However, the degree of increase became attenuated with additional days: r increased by 13·0-26·9 % from 2 to 4 d, by 6·5-16·4 % from 4 to 7 d and by 4·0-11·6 % from 7 to 12 d for energy and fifteen nutrients. In conclusion, the present study suggests that the day of the week, recording sequence and seasonality minimally contribute to the variation in nutrient intake. To measure Korean usual dietary intake using open-ended dietary instruments, 3-4 d may be needed to achieve modest precision (r>0·7) and 6-7 d for high precision (r>0·8).

Within- and between-individual variation in energy and nutrient intake in Japanese adults: effect of age and sex differences on group size and number of records required for adequate dietary assessment

BACKGROUND

Information on within- and between-individual variation in energy and nutrient intake is critical for precisely estimating usual dietary intake; however, data from Japanese populations are limited.

METHODS

We used dietary records to examine within- and between-individual variation by age and sex in the intake of energy and 31 selected nutrients among Japanese adults. We also calculated the group size required to estimate mean intake for a group and number of days required both to rank individuals within a group and to assess an individual's usual intake, all with appropriate arbitrary precision. A group of Japanese women (younger: 30-49 years, n = 58; older: 50-69 years, n = 63) and men (younger: 30-49 years, n = 54; older: 50-76 years, n = 67) completed dietary records for 4 nonconsecutive days in each season (16 days in total).

RESULTS

Coefficients of within-individual variation and between-individual variation were generally larger in the younger group than in the older group and in men as compared with women. The group size required to estimate a group's mean intake, and number of days required to assess an individual's usual intake, were generally larger for the younger group and for men. In general, a longer period was required to rank women and older adults.

CONCLUSIONS

In a group of Japanese adults, coefficients of within-individual variation and between-individual variation, which were used to estimate the group size and number of records required for adequate dietary assessment, differed by age, sex, and nutrient.

Association between milk and milk product consumption and anthropometric measures in adult men and women in India: a cross-sectional study

BACKGROUND

The nutritional aetiology of obesity remains unclear, especially with regard to the role of dairy products in developing countries.

OBJECTIVE

To examine whether milk/milk product consumption is associated with obesity and high waist circumference among adult Indians.

METHODS

Information on plain milk, tea, curd and buttermilk/lassi consumption assessed using a Food Frequency Questionnaire was obtained from the cross-sectional sib-pair designed Indian Migration Study (3698 men and 2659 women), conducted at four factory locations across north, central and south India. The anthropometric measures included were Body Mass Index (BMI) and Waist Circumference (WC). Mixed-effect logistic regression models were conducted to accommodate sib-pair design and adjust for potential confounders.

RESULTS

After controlling for potential confounders, the risk of being obese (BMI ≥ 25 kg/m(2)) was lower among women (OR = 0.57;95%CI:0.43-0.76;p ≤ 0.0001) and men (OR = 0.67;95%CI: 0.51-0.87;p = 0.005), and the risk of a high WC (men: >90 cm; women: >80 cm) was lower among men (OR = 0.71;95%CI:0.54-0.93;p = 0.005) and women (OR = 0.79;95%CI:0.59-1.05;p>0.05) who consume ≥1 portions of plain milk daily than those who do not consume any milk. The inverse association between daily plain milk consumption and obesity was also confirmed in sibling-pair analyses. Daily tea consumption of ≥ 1 portion was associated with obesity (OR = 1.51;95%CI:1.00-2.25;p>0.050) and high WC (OR = 1.65;95%CI:1.08-2.51;p>0.019) among men but not among women but there was no strong evidence of association of curd and buttermilk/lassi consumption with obesity and high waist circumference among both men and women.

CONCLUSIONS

The independent, inverse association of daily plain milk consumption with the risk of being obese suggests that high plain milk intake may lower the risk of obesity in adult Indians. However, this is an observational finding and uncontrolled confounding cannot be excluded as an explanation for the association. Therefore, confirmatory studies are needed to clarify this relationship.

Variance sources and ratios to estimate energy and nutrient intakes in a sample of adolescents from public schools, Natal, Brazil

OBJECTIVE: The aim of this study was to describe the sources of dietary variance, and determine the variance ratios and the number of days needed for estimating the habitual diet of adolescents. METHODS: Two 24 hour food recalls were used for estimating the energy, macronutrient, fatty acid, fiber and cholesterol intakes of 366 adolescents attending Public Schools in Natal, Rio Grande do Norte, Brazil. The variance ratio between the intrapersonal and interpersonal variances, determined by Analysis of Variance, was calculated. The number of days needed for estimating the habitual intake of each nutrient was given by the hypothetical correlation (r)>0.9 between the actual and observed nutrient intakes. RESULTS: Sources of interpersonal variation were higher for all nutrients and in both genders. Variance ratios were <1 for all nutrients and higher in women. Two 24 hour dietary recalls were enough to assess energy, carbohydrate, fiber and saturated and monounsaturated fatty acid intakes accurately. However, the accurate assessment of protein, lipid, polyunsaturated fatty acid and cholesterol intakes required three 24 hour recalls. CONCLUSION: Interpersonal dietary variance in adolescents was greater than intrapersonal variance for all nutrients, resulting in a variance ratio of less than 1. Two to three 24 hour recalls, depending on gender and the study nutrient, are necessary for estimating the habitual diet of this population.

The effect of community-based education for lifestyle intervention on the prevalence of metabolic syndrome and its components: tehran lipid and glucose study

BACKGROUND

It has been shown that life style modification may decrease the prevalence of metabolic syndrome, but this intervention has not been reported in community setting.

OBJECTIVES

Effect of lifestyle modification on prevalence of metabolic syndrome and its components were assessed in an urban population.

MATERIALS AND METHODS

In 6870 participants of Tehran Lipid and Glucose Study aged 20-74 years, the prevalence of metabolic syndrome and its components were measured before and after a 3.6 years interval. Lifestyle intervention was employed at a community level including 2961 individuals and also 3909 subjects which were recruited as controls. Logistic regression analysis was adjusted for age, sex and medications.

RESULTS

After 3.6 years, the rise in the prevalence of metabolic syndrome was less prominent in intervention than control group (P < 0.002 for increase of metabolic syndrome prevalence between groups), with an OR of 0.84 (confidence interval 0.75-0.95). After intervention the prevalence of abdominal obesity, elevated fasting glucose levels, elevated triglyceride and low HDL cholesterol were more prominent in control group, as compared to intervention group.

CONCLUSIONS

Community based lifestyle modifications in Tehranian adults delayed rise in the prevalence of metabolic syndrome and some of its components.

Seasonal effect on nutrient intake in adults living in Southern Brazil

The objective of this study was to investigate the effect of seasonality on nutrient intake in healthy adults from the southernmost metropolitan area of Brazil. The dietary intake (24-hour dietary recall on six different days) in a sample of 162 adults (114 women), aged 20 to 69, was obtained during the year 2007. The nutrient intake was averaged for each season and adjusted for energy intake using the residual method. The effect of season on energy, macro and micro-nutrient intake was investigated based on the Generalized Estimate Equations (GEE) model. There were statistically significant differences between seasons for carbohydrate and total fat intake after controlling for gender, age, education, and interactions. In summer carbohydrate intake was higher than other seasons while the total fat intake was lower. These findings highlight the importance of considering seasonal variations not only for evaluating dietary intake but also nutrition and public health policy recommendations, particularly in adult populations living in temperate regions.

Sources of variation of energy and nutrient intake among adolescents in São Paulo, Brazil

The aim of the current study was to describe the sources of variation of energy and nutrient intake and to calculate the number of repetitions of diet measurements to estimate usual intake in adolescents from São Paulo, Brazil. Data was collected using 24-hour dietary recalls (24hR) in 273 adolescents between 2007 and 2008. Individuals completed a repeat 24hR around two months later. The sources of variation were estimated using the random effect model. Variance ratios (within-person to between-person variance ratio) and the number of repetitions of 24hR to estimate usual intake were calculated. The principal source of variation was due to within-person variance. The contribution of day of week and month of year was less than 8%. Variations ranged from 1.15 for calcium to 7.31 for vitamin E. The number of 24hR repeats required to estimate usual intake varied according to nutrient and gender, numbering 15 for males and 8 for females.

Multi-center feasibility study evaluating recruitment, variability in risk factors and biomarkers for a diet and cancer cohort in India

BACKGROUND

India's population exhibits diverse dietary habits and chronic disease patterns. Nutritional epidemiologic studies in India are primarily of cross-sectional or case-control design and subject to biases, including differential recall of past diet. The aim of this feasibility study was to evaluate whether a diet-focused cohort study of cancer could be established in India, providing insight into potentially unique diet and lifestyle exposures.

METHODS

Field staff contacted 7,064 households within three regions of India (New Delhi, Mumbai, and Trivandrum) and found 4,671 eligible adults aged 35-69 years. Participants completed interviewer-administered questionnaires (demographic, diet history, physical activity, medical/reproductive history, tobacco/alcohol use, and occupational history), and staff collected biological samples (blood, urine, and toenail clippings), anthropometric measurements (weight, standing and sitting height; waist, hip, and thigh circumference; triceps, sub-scapula and supra-patella skin fold), and blood pressure measurements.

RESULTS

Eighty-eight percent of eligible subjects completed all questionnaires and 67% provided biological samples. Unique protein sources by region were fish in Trivandrum, dairy in New Delhi, and pulses (legumes) in Mumbai. Consumption of meat, alcohol, fast food, and soft drinks was scarce in all three regions. A large percentage of the participants were centrally obese and had elevated blood glucose levels. New Delhi participants were also the least physically active and had elevated lipids levels, suggesting a high prevalence of metabolic syndrome.

CONCLUSIONS

A high percentage of participants complied with study procedures including biological sample collection. Epidemiologic expertise and sufficient infrastructure exists at these three sites in India to successfully carry out a modest sized population-based study; however, we identified some potential problems in conducting a cohort study, such as limited number of facilities to handle biological samples.

The number of 24 h dietary recalls using the US Department of Agriculture's automated multiple-pass method required to estimate nutrient intake in overweight and obese adults

Objective

To determine the number of 24 h dietary recalls required to adequately estimate nutrient intake in overweight and obese adults using the US Department of Agriculture's (USDA) automated multiple-pass method (AMPM). In addition, the study quantified sources of variation in dietary intake, such as day of the week, season, sequence of diet interviews (training effect), diet interviewer, body weight and within- and between-subject variances in the intake of selected nutrients.

Design

Adults having a BMI of ≥ 28 but <38 kg/m2 were included in the study. The USDA's AMPM was used to obtain 24 h dietary recalls every 10 d for 6 months. Dietary intake data were analysed to adequately estimate the number of 24 h recalls necessary to assess nutrient intake. Variance component estimates were made by using a mixed-model procedure.

Setting

The greater Washington, DC, metropolitan area.

Subjects

Adults (34 men and 39 women) aged 35–65 years.

Results

Overweight and obese adults completed fourteen 24 h dietary recalls. Utilizing within- and between-subject variances requires 5–10 and 12–15 d of 24 h dietary recalls in men and women, respectively, to estimate energy and macronutrient intakes in a 6-month period. Within- and between-subject variances were the major contributors to variance in nutrient intakes. Day of the week, season, sequence, diet interviewer and body weight had little impact on variance.

Conclusions

This information is valuable for researchers planning to conduct studies on free-living individuals that include the collection of dietary intake data.

A minimum of six days of diet recording is needed to assess usual vitamin K intake among older adults

There is a growing interest in the role of vitamin K in health, especially in aging populations. Knowledge of inter- and intra-individual variability of dietary vitamin K intake could be useful to accurately assess usual intake and rank participants in epidemiological studies. Our objectives were to: 1) estimate the variance components of vitamin K intake; 2) investigate whether day of the week, season, and energy intake are factors related to intra-individual variance; and 3) calculate the requisite number of days to achieve desired degrees of accuracy for estimating individual vitamin K intake, ranking individuals and estimating regression coefficient. Vitamin K intake was assessed in 939 older adults (67-84 y) enrolled in the Québec Longitudinal Study on Nutrition and Successful Aging study using 2 sets of 3 nonconsecutive multiple-pass 24-h dietary recalls (24HR) collected 6 mo apart. Each set included 2 weekdays and one weekend day. Intra- to inter-individual variance ratios for vitamin K intake were 3.2 (95% CI = 2.6-3.9) overall, 2.6 (95% CI = 2.1-3.5) for men, and 3.7 (95% CI = 2.9-5.0) for women. Day of the week (weekdays) and season (May to October) were positively and significantly associated with vitamin K intake but explained a negligible part of intra-individual variation (<1%). Adjusting for energy intake explained <7% of variance and did not affect the variance ratio. Six to 13 24HR are required to properly rank individuals according to their usual vitamin K intake and limit attenuation of the regression coefficient. These results should be considered in studies planning to assess vitamin K intakes in older adults.

Women in resource-poor settings are at risk of inadequate intakes of multiple micronutrients

A systematic review was conducted to identify all studies that were published between 1988 and 2008 reporting micronutrient intakes of women in resource-poor settings. Inclusion criteria were study location (resource-poor), dietary assessment method (24-h recall, estimated/weighed record, or locally validated FFQ), energy and 1 or more micronutrient intakes reported (vitamin A, vitamin B-6, vitamin B-12, vitamin C, thiamin, riboflavin, niacin, folate, iron, or zinc), age range (15-50 y), sample size (≥30), and sex (female). Of the 1560 papers identified, 52 papers were included. Results showed that, except for vitamin A (29%), vitamin C (34%), and niacin (34%), the reported mean/median intakes in over 50% of studies were below the Estimated Average Requirement (EAR). Folate intake was most often below EAR (91% of studies). Regional differences were apparent for intakes of vitamins A, C, and B-6 and riboflavin; mean/median intakes in Latin America exceeded the EAR, whereas in Asia, reported mean/median intakes of vitamin C, vitamin A, and riboflavin were below the EAR in 47, 50, and 77% of the studies, respectively, as was the case for vitamin B-6 in 75% of the studies in Africa. These results suggest that inadequate intakes of multiple micronutrients are common among women living in resource-poor settings and emphasize the need for increased attention to the quality of women's diets. There is a need for more high-quality studies of women's micronutrient intakes.

Vitamin A fortification of wheat flour: considerations and current recommendations

BACKGROUND

Vitamin A deficiency is a major public health nutrition problem, affecting an estimated 190 million preschool-aged children and 19 million pregnant and lactating women globally, and 83 million adolescents in Southeast Asia alone. Its consequences (disorders) include xerophthalmia (the leading cause of early childhood blindness), increased severity of infection, anemia, and death. Because vitamin A deficiency is largely due to chronic dietary insufficiency of preformed vitamin A and proactive carotenoids, food fortification can offer an effective approach to prevention.

OBJECTIVE

To provide guidance on fortifying wheat and maize flour milled in industrial rollers for national fortification programs in countries where vitamin A deficiency is considered a public health problem.

METHODS

Critical review of the literature on the dietary gap in vitamin A intake and levels of wheat flour intake among risk groups as a basis for determining vitamin A fortificant levels. Additional review of efficacy evidence, safety and cost considerations, and country experiences related to wheat-flour fortification with vitamin A.

RESULTS

Mill-rolled wheat flour is a technically fortifiable, centrally processed food vehicle that, where routinely and adequately consumed by target groups, should be considered a candidate for fortification. Vitamin A can be stable in flour under typical, ambient conditions, with processing losses estimated at approximately 30%, depending on source and premix conditions.

CONCLUSIONS

Factors to guide a decision to fortify flour with vitamin A include the extent of deficiency, availability of other food vehicle options, the centrality of milling, market reach and population intake distributions of the flour products, the dietary vitamin A intake required, and associated costs. Large gaps persist in knowledge of these factors, which are needed to enable evidence-based fortification in most countries, leaving most decisions to fortify guided by assumptions. Where flour can and should be fortified, guidelines are given for providing nearly 25% of the Recommended Dietary Allowance for vitamin A to vulnerable groups consuming varying ranges of flour products. The costs will vary according to the level of fortification.

Effects of migration on food consumption patterns in a sample of Indian factory workers and their families

OBJECTIVES

To study the impact of migration on food consumption among Indian factory workers and their siblings and spouses.

DESIGN

A cross-sectional study was conducted to assess diet using an interviewer-administered semi-quantitative FFQ from which intake of 184 commonly consumed food items was obtained.

SETTINGS

Participants recruited from factory sites in Bangalore, Lucknow, Nagpur and Hyderabad.

SUBJECTS

The sample comprised 7049 participants (41·6 % female), and included urban, migrant and rural groups.

RESULTS

Thirteen food items were eaten by the greatest proportion of individuals on a daily basis. These were all indigenous foods. The proportion of people consuming tandoori roti, dal with vegetables, potato and ghee on a daily basis was highest in the urban sample, intermediate in the migrant group and lowest in the rural group (P ≤ 0·01). The proportion of individuals consuming Western food on a weekly basis followed a similar trend.

CONCLUSIONS

The diet of this sample is predominantly indigenous in nature, irrespective of migration status, with the prevalence of daily Western food consumption being minimal.

Number of 24-hour diet recalls needed to estimate energy intake

PURPOSE

Twenty-four-hour diet recall interviews (24HRs) are used to assess diet and to validate other diet assessment instruments. Therefore it is important to know how many 24HRs are required to describe an individual's intake.

METHOD

Seventy-nine middle-aged white women completed seven 24HRs over a 14-day period, during which energy expenditure (EE) was determined by the doubly labeled water method (DLW). Mean daily intakes were compared to DLW-derived EE using paired t tests. Linear mixed models were used to evaluate the effect of call sequence and day of the week on 24HR-derived energy intake while adjusting for education, relative body weight, social desirability, and an interaction between call sequence and social desirability.

RESULTS

Mean EE from DLW was 2115 kcal/day. Adjusted 24HR-derived energy intake was lowest at call 1 (1501 kcal/day); significantly higher energy intake was observed at calls 2 and 3 (2246 and 2315 kcal/day, respectively). Energy intake on Friday was significantly lower than on Sunday. Averaging energy intake from the first two calls better approximated true energy expenditure than did the first call, and averaging the first three calls further improved the estimate (p=0.02 for both comparisons). Additional calls did not improve estimation.

CONCLUSIONS

Energy intake is underreported on the first 24HR. Three 24HRs appear optimal for estimating energy intake.

Seasonal variations in physical activity and implications for human health

This review explores the implications of seasonal changes in physical activity for fitness and human health. Photosensitivity and nutrient shortages mediate animal hibernation via the hypothalamus and changes in leptin and ghrelin concentrations. Opportunities for hunting and crop cultivation determine seasonal activity in under-developed human societies, but in developed societies temperature and rainfall are dominant influences, usually over-riding innate rhythms. Both questionnaire data and objective measurements show that many groups from children to the elderly increase their physical activity from winter to spring or summer. Measurements of maximal oxygen intake and muscle strength commonly show parallel seasonal changes. However, potential effects upon body mass and body fat may be counteracted by changes of food intake; subsistence agriculturists sometimes maintain or increase physical activity at the expense of a decrease in body mass. In developed societies, body fat commonly increases during the winter, with parallel changes in blood lipids, blood pressure and blood coagulability; moreover, these changes are not always fully reversed the following summer. Most developed societies show increased all-cause and cardiac mortalities in the winter. Health consequences of seasonal variations in physical activity including an increased vulnerability to cardiac catastrophe and a year-by-year increase in total body fat seem most likely if the average level of physical activity for the year is low. Public health recommendations should underline the importance of maintaining physical activity during adverse environmental conditions by adapting clothing, modifying behaviour and exploiting any available air-conditioned indoor facilities.

Seasonal variation in food intake, physical activity, and body weight in a predominantly overweight population

OBJECTIVE

To describe seasonal variation in food intake, physical activity, and body weight in a predominantly overweight population.

DESIGN

A longitudinal observational study.

SETTING

Most of the study participants were recruited from a health maintenance organization (HMO) in central Massachusetts, USA. Additional individuals of Hispanic descent were recruited from outside of the HMO population to increase the ethnic diversity of this sample.

SUBJECTS

Data from 593 participants, aged 20-70, were used for this investigation. Each participant was followed quarterly (five sampling points: baseline and four consecutive quarters) for 1-year period. Body weight measurements and three 24-h dietary and physical activity recalls were obtained on randomly selected days (including 2 weekdays and 1 weekend day) per quarter. Sinusoidal regression models were used to estimate peak-to-trough amplitude and phase of the peaks.

RESULTS

Daily caloric intake was higher by 86 kcal/day during the fall compared to the spring. Percentage of calories from carbohydrate, fat and saturated fat showed slight seasonal variation, with a peak in the spring for carbohydrate and in the fall for total fat and saturated fat intake. The lowest physical activity level was observed in the winter and the highest in the spring. Body weight varied by about 1/2 kg throughout the year, with a peak in the winter (P<0.001 winter versus summer). Greater seasonal variation was observed in subjects who were male, middle aged, nonwhite, and less educated.

CONCLUSIONS

Although there is seasonal variation in diet, physical activity and body weight, the magnitude of the change is generally small in this population.

SPONSORSHIP

US National Heart, Lung and Blood Institute.

Sources of variation in nutrient intakes among men in Shanghai, China

BACKGROUND AND OBJECTIVE

Random errors, from any source, will attenuate epidemiological risk estimates. Before we launched the Shanghai Men's Health Study (SMHS), a large population-based cohort study investigating the diet-cancer association among Chinese men, a dietary calibration study was conducted among 96 men aged 40-75 years (mean age 56.5 years), with biweekly 24-hour dietary recalls (24HDRs) implemented over a 1-year period. Data from this study were analysed to evaluate the nature and magnitude of variances for intake of 26 nutrients among SMHS participants, to compare variance ratios of 26 nutrients among Chinese men and women and individuals in other studies, and to estimate the number of 24HDRs required for future dietary calibration studies in similar populations.

DESIGN

Ninety-six healthy, free-living men in Shanghai were administered biweekly 24HDR interviews 24 times over a 1-year period. To assess between-individual and within-individual contributions to variance, a mixed effects model was fitted and ratios of within-individual to between-individual (sigma(w)(2)/sigma(b)(2)) dietary intake variances were computed.

SETTING

Shanghai, China.

RESULTS

In agreement with reports from studies conducted in the USA and many other countries, we found that within-individual variances were usually larger than between-individual variances in dietary intake for all nutrients. The sum of all other variation (e.g. weekday and weekend, seasonal, interviewer) accounted for less than 5% of total variation. Ratios of within- to between-individual variances (for log-transformed data) ranged from 1.25 for carbohydrate intake to near 8 for delta-tocopherol intake.

CONCLUSIONS

The results of this study suggest that among middle-aged and elderly Chinese men in Shanghai, within- and between-individual variation account for more than 95% of the total variation for 26 nutrients. Further dietary validation studies in the same population could be adequately carried out with only 12 days of dietary recalls, if 100 participants were enrolled.

Variation in nutrient intakes among women in Shanghai, China

BACKGROUND

In 1997, we launched a large population-based cohort study, the Shanghai Women Health Study (SWHS), to investigate diet in relation to cancer risk among 74 943 Chinese women. Simultaneously, a dietary calibration study was conducted among 200 SWHS participants with biweekly 24-h dietary recall (24HDR) over a 1-y period in order to evaluate the validity and reliability of the SWHS food frequency questionnaire (FFQ).

OBJECTIVE

The objectives of the current study were to evaluate the nature and magnitude of variances for intake of 26 nutrients among SWHS participants, and to estimate the number of 24HDR needed for estimate intake of the 26 nutrients examined in the study population.

DESIGN

In all, 1-y biweekly 24HDR collected from 200 healthy, free-living women aged between 40 and 70 y, who participated in the SWHS dietary calibration study, was analyzed by mixed effects model and ratios of within-individual and between-individual dietary intake variances (sigma(w)(2)/sigma(b)(2)) were estimated.

RESULTS

In agreement with reports from studies conducted in the US, we found that within-individual variances were larger than between-individual variances in dietary intake of most nutrients. The sum of all other variation (eg, weekday and weekend, seasonal, interviewer) accounted for less than 5% of total variation. Ratios of within- to between-individual variances (for log transformed data) ranged from 1.05 (carbohydrate) to 2.79 (fat) for macronutrient intake, 1.74 (niacin) to 8.48 (delta-tocopherol) for vitamin intake, and 1.35 (phosphorus) to 5.59 (sodium) for mineral intake.

CONCLUSIONS

The results of this study suggest that within- and between-individual differences in nutrient intake are the major sources of variation in this population of adult Chinese women. Cultural practices as well as seasonal supply and consumption patterns of vegetable intake are likely the major contributors to the variation. Implications of these results are discussed.

Opportunities for cancer epidemiology in developing countries

Most cancer epidemiology studies involve people living in North America and Europe, which represent only a fraction of the global population. The wide variety of dietary, lifestyle and environmental exposures, as well as the genetic variation among people in developing countries can provide valuable new information on factors that contribute to cancer or that protect against it. What are the challenges and advantages to performing large epidemiological studies in developing nations?

Nutrient intake of first generation Gujarati Asian Indian immigrants in the U.S

OBJECTIVE

To examine the nutrient intake of Gujarati Asian Indian immigrants in the U.S. and the influence of length of residence in the U.S. and socioeconomic status (SES) on their macronutrient intake.

METHODS

Subjects were male (n = 90) and female (n = 99) Gujarati Asian Indian immigrants over the age of 45. Each participant completed a 24-hour dietary recall. Dietary recalls were analyzed using Food Processor nutrient analysis software. Participants were classified into recent immigrants (<10 years length of residence in the U.S.) and long-term immigrants (>10 years length of residence in the U.S.) and into low, medium and high education groups, based on highest level of education achieved, to examine the influence of these variables on their macronutrient intake.

RESULTS

The macronutrient contributions to the total energy intake of these Gujarati Asian Indian immigrants were as follows: carbohydrate 57%, protein 12% and total fat 33%. The diets were low in cholesterol (<100 mg/day) and high in dietary fiber (>/=25 g/day). Reported intakes of vitamin D, calcium (women only), potassium (women only), copper and zinc were less than two-thirds of the recommendations. Significant differences (p < 0.05) in macronutrient intake were observed based on length of residence in the U.S. and SES. Regression analysis indicates age, total energy intake, length of residence in the U.S. and SES to have a significant influence on the nutrient intake of these Gujarati Asian Indian immigrants.

CONCLUSION

The nutrient intakes of these Gujarati Asian Indian immigrants indicate both inadequacies and excesses of select macro and micronutrients. These nutrient inadequacies and excesses can impact overall health and risk of chronic diseases of these individuals. Further investigation of the influence of the diets of these immigrants on their health is warranted.

Dietary exposures and oral precancerous lesions in Srikakulam District, Andhra Pradesh, India

OBJECTIVE

To test the effect of dietary nutrients on oral precancerous lesions in a reverse-smoking (i.e. smoking with the glowing end inside the mouth) population in South India.

DESIGN

Case-control. Cases with precancerous lesions were matched to an equal number of lesion-free controls matched on age (+/- 5 years), sex and village. All subjects used tobacco in some form. Dietary data were obtained using an interviewer-administered food-frequency questionnaire, designed for use in this population. All interviews were conducted blinded to the disease status of the subject. Data were analysed using logistic regression.

SETTING

Nineteen rural villages in Srikakulam District, Andhra Pradesh.

SUBJECTS

From a survey of 6007 tobacco users, 485 (79% women) were found to have precancerous, mostly palatal, lesions (cases), and 487 lesion-free subjects were selected as controls.

RESULTS

All eligible subjects consented to participate and nearly all (> 99%) had complete data for analyses. Reverse smoking was the most common form of tobacco use among cases (81.9%) and controls (73.5%), and reverse smokers were 5.19 times more likely than chewers to have these lesions (95% confidence interval = 1.35, 19.9). After controlling for relevant covariates, including the type of tobacco use, protective linear effects were observed for zinc (70% reduction across the interquartile range, P < 0.002), calcium (34% reduction, P < 0.002), fibre (30% reduction, P < 0.009), riboflavin (22% reduction, P < 0.03) and iron (17% reduction, P < 0.05).

CONCLUSIONS

Several dietary nutrients appear to protect against oral precancerous lesions that are strongly associated with reverse smoking. The results of this study indicate scope for targeting dietary factors in preventing oral cancer, which should be coupled with aggressive anti-tobacco use efforts.