The use of external within-person variance estimates to adjust nutrient intake distributions over time and across populations

OBJECTIVE: To examine the utility of using external estimates of within-person variation to adjust usual nutrient intake distributions. DESIGN: Analyses of the prevalence of inadequate intake of an example nutrient by the Estimated Average Requirement (EAR) cut-point method using three different methods of statistical adjustment of the usual intake distribution of a single 24-hour recall in Russian children in 1996, using the Iowa State University method for adjustment of the distribution. First, adjusting the usual intake distribution with day 2 recalls from the same 1996 sample (the correct method); second, adjusting the distribution using external variance estimates derived from US children in 1996; and third, adjusting the distribution using external estimates derived from Russian children of the same age in 2000. We also present prevalence estimates based on naive statistical analysis of the unadjusted distribution of intakes. SETTING/SUBJECTS: Children drawn from the Russia Longitudinal Monitoring Survey in 1996 and 2000 and from the 1996 Continuing Survey of Food Intakes by Individuals. RESULTS: When the EAR cut-point method is applied to a single recall, the resulting prevalence estimate in this study is inflated by 100-1300%. When the intake distribution is adjusted using an external variance estimate, the prevalence estimate is much less biased, suggesting that any adjustment may give less biased estimates than no adjustment. CONCLUSIONS: In moderately large samples, adjusting distributions with external estimates of variances results in more reliable prevalence estimates than using 1-day data.     

Inadequate intakes of dietary zinc among pregnant women from subsistence households in Sidama, Southern Ethiopia

OBJECTIVE: To assess the prevalence of zinc inadequacy based on dietary intakes and plasma zinc concentrations and, simultaneously, the prevalence of inadequate intakes of energy, protein, calcium and iron. DESIGN: A cross-sectional study of a convenience sample of subsistence farming households in Sidama, Southern Ethiopia. SUBJECTS: Dietary intakes were calculated from 1-day weighed food records and 40 repeats from 99 pregnant women in the third trimester using analysed values of major staple foods for zinc, iron, calcium and phytate. The distribution of observed intakes was adjusted for usual intakes and the prevalence of inadequacy estimated using the estimated average requirement (EAR) cutpoint method. Prevalence of inadequacy for zinc, protein and iron intakes were compared with those based on biochemical measures. RESULTS: Prevalence of zinc inadequacy was very high: 99% for US FNB EAR and 100% for IZiNCG EAR compared to 72% based on low plasma zinc concentrations. Corresponding prevalence estimates for iron were much lower: 4% for inadequate intakes based on US FNB EAR vs. 8.7% for iron deficiency anaemia (haemoglobin < 110 g l-1; ferritin < 12 microg l-1) and 32.3% for low storage iron. Prevalence of inadequacy for protein was 100% for adjusted intakes and 91% for serum albumin < 32 g l-1. For calcium, 74% were at risk for inadequate intakes. CONCLUSION: The high prevalence of inadequate intakes of zinc and protein was reasonably consistent with those based on biochemical measures. Such dietary deficits could be overcome by regular consumption of cellular animal protein. In contrast, both dietary and biochemical measures of iron inadequacy were low.     

24-hour national dietary survey data: how do we interpret them most effectively?

OBJECTIVE: To illustrate the effect of common mistakes when using 24-hour national dietary survey data to estimate the prevalence of inadequate nutrient intakes. DESIGN: Raw data on nutrient intake from the Australian 1995 National Nutrition Survey were adjusted for within-person variance using standard techniques and corrected for underreporting using the criteria of Goldberg et al. The distributions for six nutrients were compared with current dietary reference values from the UK, USA and Australia. SETTING: A national sample of the Australian population with a 61.4% response rate. RESULTS: Adjusting for within-person variance reduced the range of nutrient intakes to 66-80% of the raw data range and the proportion with intakes below the estimated average requirement (EAR) by up to 20%. Excluding underreporters further reduced the proportion below the EAR by up to 10%. Using the dietary reference values from different countries also resulted in some markedly different estimates. For example, the prevalence of low folate intakes ranged from < 1 to 92% for adult women depending on the reference used. Except for vitamin A and protein, the prevalence of low intakes was invariably higher for women than for men. CONCLUSIONS: Estimates of the prevalence of low nutrient intakes based on raw 24-hour survey data are invariably misleading. However, even after adjustment for within-person variance and underreporting, estimates of the prevalence of low nutrient intakes may still be misleading unless interpreted in the light of the reference criteria used and supported by relevant biochemical and physiological measures of nutritional status.     

Assessment of intake inadequacy and food sources of zinc of people in China

OBJECTIVES: To assess the intake inadequacy and food sources of zinc of people in China. DESIGN AND SUBJECTS: Diets of 68 962 subjects aged 2-101 years (urban 21 103, rural 47,859) in the 2002 China National Nutrition and Health Survey were analysed. Dietary intake was assessed using 24-hour recall for three consecutive days. Zinc intake inadequacy was calculated based on values suggested by the World Health Organization. RESULTS: The median zinc intake ranged from 4.9 mg day- 1 (urban girls, 2-3 years) to 11.9 mg day-1 (rural males, 19+ years). The zinc density of urban residents (2-3 to 19+ years) was 5.0-5.3 mg day-1 (1000 kcal)-1, significantly higher than that of their rural counterparts (4.7-4.8 mg day-1 (1000 kcal)-1). Differences in food sources of zinc from cereal grains (27.4-45.1 vs. 51.6-63.2%) and animal foods (28.4-54.8 vs. 16.8-30.6%) were found between urban and rural residents. Zinc from vegetables and fruits (8.2-13.8 vs. 9.7-12.4%) and legumes (1.3-3.3 vs. 2.5-3.4%) was comparable between urban and rural residents. The proportion of zinc intake inadequacy ranged between 2.8% (urban females, 19+ years) and 29.4% (rural lactating women). Rural residents had higher proportions of zinc intake inadequacy than their urban counterparts. Significantly higher proportions of zinc inadequacy were found in the category of phytate/zinc molar ratio >15 for both rural and urban residents. CONCLUSIONS: About 20% of rural children are at risk of inadequate zinc intake, with phytate as a potential important inhibitor. Moreover, lactating women are also considered a vulnerable group.     

Underreporting of energy intake from a self-administered food-frequency questionnaire completed by adults in Montreal

BACKGROUND: Energy intake determined from self-reported dietary assessment methods may be underreported. Therefore, it is important that such methods be validated against another with known validity for energy intake or energy expenditure. METHODS: We investigated potential underestimation of energy intake obtained from our semi-quantitative food-frequency questionnaire (FFQ) administered between 2000 and 2001 in the metropolitan area of Montreal, Canada. The study population included 246 adults aged 18 to 82 years. The ratio of energy intake to estimated basal metabolic rate (EI/BMR) was used to assess underreporting and physical activity was determined from self-administered questions. Comparison of the EI/BMR ratio with the Goldberg statistical cut-off allowed us to detect individuals who were low energy reporters (LERs). LERs and non-LERs were compared to determine if they differed on sociodemographic, anthropometric and lifestyle variables. RESULTS: The EI/BMR ratio was 1.26 for men and 1.32 for women. LERs represented 43% of the sample of individuals. Male LERs accounted for 54% compared with 35% among females. Underreporting of energy intake was highest in men and individuals who were older, heavier, with higher body mass index and lower education level. A higher proportion of male LERs perceived their financial situation as adequate while a greater proportion of female LERs considered themselves poor. CONCLUSION: Our data suggest that underreporting of energy intake from the FFQ was considerable and may bias dietary interpretation. As this was uneven across the sample, it is crucial to recognise the characteristics of LERs in order to increase the validity of reported energy intake.     

Energy, macro- and micronutrient intake among a true longitudinal group of South African adolescents at two interceptions (2000 and 2003): the Birth-to-Twenty (Bt20) Study

OBJECTIVE: This study reports on the energy, macro- and micronutrient intakes of a true longitudinal group of 143 urban black South African children from the Birth-to-Twenty (Bt20) study at two interceptions (2000 and 2003) when they were 10 and 13 years old, respectively. METHODS: Subjects resided in the urban Johannesburg/Soweto area of the Gauteng Province in South Africa. Dietary intake was assessed using a semi-quantitative food-frequency questionnaire. The coded data were analysed using SAS. RESULTS: Mean daily intake of energy, all six macronutrients and most micronutrients (17/19) increased from 2000 to 2003. Of the 19 micronutrients investigated, the mean daily intake of eight (calcium, iron, zinc, vitamin A, riboflavin, nicotinic acid, pantothenic acid and biotin) fell below the recommended dietary allowance (RDA) at both interceptions. More than 70% of the children consumed less than the RDA for these same eight nutrients. From 2000 to 2003, there was a decrease in the percentage of children falling below the RDA for energy (from 73 to 59%), but an increase in the percentage of children falling below the RDA for most of the micronutrients. There was a positive percentage change in mean daily intake for all 26 macro- and micronutrients from 2000 to 2003. CONCLUSION: Mean daily intake of nutrients increased from 2000 to 2003, but intakes for most micronutrients were still below the RDA at both interceptions for a large percentage of the children. The study has provided valuable information on the nutrient intake and change in intake over time among a longitudinal group of South African adolescents.     

Joint Modeling of Spatial Variability and Within-Row Interplot Competition to Increase the Efficiency of Plant Improvement

Trials in the early stages of selection are often subject to variation arising from spatial variability and interplot competition, which can seriously bias the assessment of varietal performance and reduce genetic progress. An approach to jointly model both sources of bias is presented. It models genotypic and residual competition and also global and extraneous spatial variation. Variety effects were considered random and residual maximum likelihood was used for parameter estimation. Competition at the residual level was examined using two special simultaneous autoregressive models. An equal-roots second-order autoregressive (EAR(2)) model is proposed for trials where competition is dominant. An equal-roots third-order autoregressive (EAR(3)) model allows for competition and spatial variability. These models are applied to two yield data sets from an Australian sugarcane selection program. One data set is in the paper and the other is in supplementary material available online. To determine the effect of simultaneously adjusting for spatial variability and interplot competition on selection, the percentages of superior varieties in common in the top 15% for the joint model and classical approaches were compared. Agreement between the two approaches was 45 and 84%. Hence, for some trials there are large differences in varieties advanced to the next stage of selection.     

Improving the nutritional status of food-insecure women: first, let them eat what they like

OBJECTIVE: To determine the extent to which identified nutrient inadequacies in the dietary intakes of a sample of food-insecure women could be ameliorated by increasing their access to the 'healthy' foods they typically eat. DESIGN: Merged datasets of 226 food-insecure women who provided at least three 24-hour dietary intake recalls over the course of a month. Dietary modelling, with energy adjustment for severe food insecurity, explored the effect of adding a serving of the woman's own, and the group's typically chosen, nutrient-rich foods on the estimated prevalence of nutrient inadequacy. SETTING AND SUBJECTS: One study included participants residing in 22 diverse community clusters from the Atlantic Provinces of Canada, and the second study included food bank attendees in Toronto, Ontario, Canada. Of the 226 participants, 78% lived alone with their children. RESULTS: While nutritional vulnerability remained after modelling, adding a single serving of either typically chosen 'healthy' foods from women's own diets or healthy food choices normative to the population reduced the prevalence of inadequacy by at least half for most nutrients. Correction for energy deficits resulting from severe food insecurity contributed a mean additional 20% improvement in nutrient intakes. CONCLUSIONS: Food-insecure women would sustain substantive nutritional gains if they had greater access to their personal healthy food preferences and if the dietary compromises associated with severe food insecurity were abated. Increased resources to access such choices should be a priority.     

Incorporating parameter uncertainty into prediction intervals for spatial data modeled via a parametric variogram

In spatial predictions, researchers usually treat the estimated theoretical variogram parameters as known without error and ignore the variability of the parameter estimators. Although the prediction is still unbiased, the prediction error is usually underestimated. Therefore, the coverage probability of the prediction interval usually is lower than the nominal probability. A simulation study is performed to show how the coverage probability for prediction relates to the true range and sill of an exponential variogram. This article proposes two parametric bootstrap methods to incorporate the variability of the corresponding parameter estimators. A simulation study is performed to evaluate the coverage probability of these proposed methods. Finally, we apply the parametric bootstrap methods to a real dataset and compare the results with those from naive (i.e., treating estimated parameters as known) and Bayesian methods.     

Validity and reproducibility of two semi-quantitative alcohol frequency questionnaires for the Colombian population

OBJECTIVE: To determine the relative validity and reproducibility of two alcohol intake frequency questionnaires (AFQ-A; AFQ-B), designed to classify subjects according to their alcohol intake level, in Bucaramanga, Colombia. METHOD: One hundred and nine randomly selected subjects, aged between 20 and 60 years, completed three 30-day semi-quantitative alcohol intake records (30-DR). The AFQs were applied three months after the last 30-DR. AFQ-A contained 53 items; AFQ-B contained five items, with the alcoholic drinks for AFQ-B selected by Max_r. The correlation and agreement between alcohol intake assessed with the AFQs and the 30-DR were obtained using Pearson's correlation coefficient (r), Lin's concordance correlation coefficient (rhoC), Spearman's rank correlation coefficient (rS), Bland and Altman's limits of agreement (LOA) and Cohen's weighted kappa statistic (Kw). RESULTS: The reproducibility of the 30-DR was poor; rS ranged from 0.33 to 0.41. The reproducibility of the AFQs was higher, with rS between 0.50 and 0.73. The agreement (Kw) of the 30-DR and the AFQs was 0.40. The lower and upper LOA were between -56.4% and -11.0%. The AFQs and 30-DR were well correlated. Assessment of relative validity between the two methods yielded r values for alcohol between 0.52 and 0.60, which reduced to 0.20-0.29 after energy adjustment. CONCLUSIONS: These AFQs may be useful to rank subjects according to their alcohol intake. The AFQ-B is easy and quick to apply, and is also highly cost-effective.     

Nutrition and the burden of disease in New Zealand: 1997-2011

OBJECTIVE: To estimate the burden of disease due to selected nutrition-related risk factors (high total blood cholesterol, high systolic blood pressure, high body mass index (BMI) and inadequate vegetable and fruit intake) in 1997, as well as the burden that could potentially be avoided in 2011 if small, favourable changes in the current risk factor distribution were to occur. DESIGN: Data on risk factor levels, disease burden and risk associations were combined using comparative risk assessment methodology, a systematic approach to estimating both attributable and avoidable burden of disease. Disease outcomes assessed varied according to risk factor and included ischaemic heart disease, stroke, type 2 diabetes mellitus and selected cancers. SETTING: New Zealand. RESULTS: Approximately 4500 deaths (17% of all deaths) in 1997 were attributable to high cholesterol, 3500 (13%) to high blood pressure, 3000 (11%) to high BMI and 1500 (6%) to inadequate vegetable and fruit intake. Taking prevalence overlap into account, these risk factors were estimated jointly to contribute to approximately 11 000 (40%) deaths annually in New Zealand. Approximately 300 deaths due to each risk factor could potentially be avoided in 2011 if modest changes were made to each risk factor distribution. CONCLUSIONS: High cholesterol, blood pressure and BMI, as well as inadequate vegetable and fruit intake, are major modifiable causes of death in New Zealand. Small changes in the population distribution of these risk factors could have a major impact on population health within a decade.     

台湾地区溪流生态基础流量推估——和平溪上游案例研究

在研究山区河川的水理计算方法时有争议,尚未有定论,一般研究河川基础流量以采用历史流量评估法及水理评估法为常用的量化方式。本研究主要以“历史流量评估法”进行生态基础流量分析。依据面积与流量经验值估算,本研究推估之最小生态基础流量约为0.32～0.95cms;依照日本一般生态基础流量计算标准,则维护生态最小放流量应为1.06cms。利用Tennant法计算生态基础流量时应随时间季节及水文条件变化。推估值于丰水期之基础流量应为1.46cms,枯水期应为0.61cms。若按日流量延时曲线之95%为分析基础,则查询     

Internal and external validation strategies for the evaluation of long-term effects in NIR calibration models

Some of the practical aspects of long-term calibration-set building are presented in this study. A calibration model able to predict the Kolbach index for brewing malt is defined, and four different validations and resampling schemes were applied to determine its real predictive power. The results obtained demonstrated that one single performance criterion might be not sufficient and can lead to over- or underestimation of the model quality. Comparing a simple leave-one-sample-out cross-validation (CV) with two more challenging CVs with leave-N-samples-out, where the resamplings were repeated 200 times, it is demonstrated that the error of prediction value has an uncertainty, and these values change according to the type and the number of validation samples. Then, two kinds of test-set validations were applied, using data blocks based on the sample collection's year, demonstrating that it is necessary to consider long-term effects on NIR calibrations and to be conservative in the number of factors selected. The conclusion is that one should be modest in reporting the prediction error because it changes according to the type of validation used to estimate it and it is necessary to consider the long-term effects.     

An urban-rural comparison of the prevalence of the metabolic syndrome in Eastern China

OBJECTIVE: To assess the impact of urbanisation on the prevalence of the metabolic syndrome in Chinese adults. DESIGN: As part of a community-based cross-sectional survey conducted in 2002, a sample from rural and urban populations in East China was obtained. The metabolic syndrome is defined by the National Cholesterol Education Program Adult Treatment Panel III criteria (ATP III) and the modified ATP III, which recommended a lower waist circumference cut-off for Asians.Setting Field sites in Jiangxi and Anhui provinces and the Jing'an District of Shanghai, China. SUBJECTS: A total of 529 non-pregnant, non-lactating urban and rural adults, aged 20-64 years without diagnosed diabetes. RESULTS: Dwelling in urban areas was associated with higher dietary fat intake and slightly lower total energy intake, and with significantly lower occupational physical activity. Using the ATP III criteria, the prevalence of the metabolic syndrome was significantly higher for urban than rural men (12.7 vs. 1.7%, P < 0.001), and was similar between urban and rural women (10.1 vs. 9.7%, P = 0.17). These urban-rural differences were greatly enhanced when the modified ATP III criteria for the syndrome were used, for men (34.3 vs. 2.7%, P < 0.01) and women (24.1 vs. 11.4%, P = 0.07). The Asian waist circumference cut-offs (90 and 80 cm for men and women, respectively) had a better combination of sensitivity and specificity in identifying other metabolic disorders, which included high glucose, high blood pressure, high triglycerides and low high-density lipoprotein cholesterol, for this population.Conclusion For the Chinese population, urban dwelling was associated with higher prevalence of the metabolic syndrome, especially in men.     

Dilution errors in aflatoxin determinations caused by compounds extracted from peanuts

Several methods have been developed to analyze peanuts for aflatoxin by using thin layer chromatography (TLC). These methods depend on solvent extraction of aflatoxin from a sample of the product. Unfortunately, solvent solutions used to extract aflatoxin from peanuts also extract measurable quantities of other compounds such as oils, fats, sugars, and protein. The volume of these extracted compounds causes error in measuring the proportion of the solvent solution analyzed for aflatoxin. Also, because the cleanup procedures for some methods are inadequate, the volume of some of these extracted compounds also causes error in measuring the proportion of the extracted aflatoxin placed on TLC plates. These 2 errors cause underestimation of aflatoxin concentrations by approximately 11, 14, and 5% for the CB method, the modified version of the BF method generally used for raw peanuts, and a water slurry method, respectively. The correction specified by the CB method for fats in the extraction solvent reduces the approximate error for the CB method from 11 to 1%.     

Separate estimates of portion size were not essential for energy and nutrient estimation: results from the Southern Community Cohort food-frequency questionnaire pilot study

OBJECTIVE: A food-frequency questionnaire (FFQ) was developed to assess habitual dietary intake in the Southern Community Cohort Study (SCCS), a prospective epidemiological study to analyse disparities in cancer and other chronic diseases between African-Americans and Whites. DESIGN: Frequency and portion size estimates were obtained for each of 104 foods. Daily intakes of 13 food groups, energy and 18 nutrients were computed. Each participant's rank and quintile classification of nutrient intakes was determined with and without the use of the subject's reported portion size. SUBJECTS: The sample was obtained from the SCCS pilot study conducted in Tennessee, Mississippi and Florida, and consisted of 209 adults, 54% African-American, with a mean (standard deviation) age of 57.1 (12.5) years. RESULTS: Correlations between the ranks from the two methods of estimation were high, ranging from 0.66 to 0.94 for food groups and 0.81 to 0.94 for nutrients. Pearson correlations were similarly high for food groups and nutrients. Concordance in exact quintile rank across the nutrient indices ranged from 52 to 70%, rising to 90-99% for concordance within adjacent quintiles. CONCLUSIONS: To reduce the respondents' burden and to increase data completeness, the assignment of a uniform portion size when scoring the SCCS FFQ was considered acceptable.     

Ein Verfahren zur Gewinnung der Gleichgewichts-Bodenporenlösung

A procedure for obtaining the equilibrium soil pore solution A percolation system for 100 cm³ soil cores is presented. Only filter materials with negligeable interferring properties are used, and during percolation an air filled porosity is maintained. Results from soil cores of a spruce site show, that conventional homogenization of soil samples may lead to a great loss of information about the variability of acidity parameters and to an underestimation of the real soil acidification in the rhizosphere.     

Development and simulated validation of a food-frequency questionnaire for the Colombian population

OBJECTIVE: To develop a food-frequency questionnaire (FFQ) useful for ranking of nutrient intakes. DESIGN: Subjects consuming their regular diet completed 7 days of weighed intake registry (7-WIR). Foods for the FFQ were selected by stepwise multiple regression. The FFQ was then completed for each subject using data on individual food consumption from the 7-WIR. The correlation and agreement between the extrapolated FFQ and the 7-WIR data were assessed using Spearman's rank correlation coefficients (rS) and Bland and Altman's limits of agreement (LOA). SETTING: Bucaramanga, Colombia. SUBJECTS: We studied 97 randomly selected 20-40-year-old subjects. RESULTS: Sixty foods were selected for the FFQ. The 7-WIR and the extrapolated FFQ intake estimates correlated well. rS was 0.58 for energy, 0.53 for carbohydrate, 0.50 for total fat, and 0.48 for protein. For micronutrients, rS varied from 0.46 (manganese) to 0.71 (vitamin B12). FFQ average intake estimates were 83%, 80%, 86.2% and 86.4% of 7-WIR estimates for energy, carbohydrate, total fat and protein, respectively. LOA for these nutrients ranged between 45% and 165%. FFQ micronutrient intakes were on average 96% (median) of those from the 7-WIR, and the median lower and upper LOA were 50% and 203%. However, there was no indication that the degree of agreement varied with the level of intake. CONCLUSIONS: According to our simulated validation, this FFQ may be useful to rank subjects by nutrient intake. Its validity against standard independent measurements and its applicability to other subsets of the Colombian population should be carefully considered.     

Comparing methods for handling missing values in food-frequency questionnaires and proposing k nearest neighbours imputation: effects on dietary intake in the Norwegian Women and Cancer study (NOWAC)

OBJECTIVE: To investigate item non-response in a postal food-frequency questionnaire (FFQ), and to assess the effect of substituting/imputing missing values on dietary intake levels in the Norwegian Women and Cancer study (NOWAC). We have adapted and probably for the first time applied k nearest neighbours (KNN) imputation to FFQ data. DESIGN: Data from a recent reproducibility study were used. The FFQ was mailed twice (test-retest) about 3 months apart to the same subjects. Missing responses in the test FFQ were imputed using the null value (frequencies = null, amount = smallest), the sample mode, the sample median, KNN, and retest values. SETTING: A methodological substudy of NOWAC, a national population-based cohort. SUBJECTS: A random sample of 2000 women aged 46-75 years was drawn from the cohort in 2002 (response 75%). The imputation methods were compared for 1430 women who completed at least 50% of the test FFQ. RESULTS: We imputed 16% missing values in the overall test data matrix. Compared to null value imputation, the largest differences in estimated dietary intake were seen for KNN, and for food items with a high proportion of missing. Imputation with retest values increased total energy intake, indicating that not all missing values are caused by respondents failing to specify no consumption, and that null value imputation may lead to underestimation and misclassification. CONCLUSION: Missing values in FFQs present a methodological challenge. We encourage the application and evaluation of newer imputation methods, including KNN, which may reduce imputation errors and give more accurate intake estimates.     

Misperceptions, inactivity and maternal factors may drive obesity among Barbadian adolescents

OBJECTIVES: To describe (1) the prevalence of overweight and obesity and their association with physical activity; (2) the effect of different cut-off points for body mass index (BMI) on weight status categorisation; and (3) associations of weight status with perceptions of body size, health and diet quality. DESIGN: A cross-sectional study. SETTING: Secondary schools in Barbados. SUBJECTS: A cohort of 400 schoolchildren, 11-16 years old, selected to study physical education practices. RESULTS: Prevalence of overweight (15% boys; 17% girls) and obesity (7% boys; 12% girls) was high. Maternal obesity, as defined by the International Obesity Task Force (IOTF) BMI cut-off points, predicted weight status such that reporting an obese mother increased the odds of being overweight by 5.25 (95% confidence interval: 2.44, 11.31). Physical activity was inversely associated with weight status; however levels were low. Recreational physical activity was not associated with weight status in either category. Overweight subjects tended to misclassify themselves as normal weight and those who misclassified perceived themselves to be of similar health status to normal-weight subjects. The National Center for Health Statistics and IOTF BMI cut-off points produced different estimates of overweight and obesity. CONCLUSIONS: Our findings suggest that inadequate physical activity and ignorance related to food and appropriate body size are promoting high levels of adiposity with a strong contribution from maternal obesity, which may be explained by perinatal and other intergenerational effects acting on both sexes. Prevalence studies and local proxy tools for adiposity assessment are needed.