Serum Zinc Is a Major Predictor of Anemia and Mediates the Effect of Selenium on Hemoglobin in School-Aged Children in a Nationally Representative Survey in New Zealand.

BACKGROUND: Zinc, selenium, and vitamin D status of New Zealand (NZ) school-aged children was examined in a national survey in 2002. To our knowledge, however, the role of these micronutrients as predictors of hemoglobin has not been explored despite plausible mechanisms for such relations. OBJECTIVE: We examined the relations of iron, zinc, selenium, and vitamin D status with hemoglobin and anemia in children of New Zealand European and other (NZEO) ethnicity enrolled in the 2002 Children's Nutrition Survey and explored whether zinc mediated the relation between selenium and hemoglobin. METHODS: Multivariate regression was performed to examine the relations of serum micronutrient biomarkers, acute inflammation, socioeconomic status, and body mass index (BMI) with hemoglobin and anemia of NZEO children aged 5-15 y (n = 503). A mediation analysis also investigated direct and indirect (through zinc) relations between selenium and hemoglobin. RESULTS: In total, 4.6% of the children were anemic, 3.2% had depleted iron stores, and none had iron deficiency anemia. The prevalence of low serum zinc (<8.7-10.1 µmol/L depending on age and sex), selenium (<0.82 µmol/L), and 25-hydroxyvitamin D (<50 nmol/L) was 14.1%, 22.9%, and 48.5%, respectively. Major predictors of hemoglobin were serum zinc, age, and BMI-for-age z score (P < 0.001); log ferritin and being female were also statistically significant (P < 0.05). Selenium had an indirect effect that was mediated by zinc, with a significant effect of selenium on zinc (P = 0.002) and zinc on hemoglobin (P < 0.001). Zinc was the only variable associated with anemia risk (OR: 5.49; 95% CI: 1.95, 15.46). CONCLUSIONS: Low serum zinc was an independent risk factor for anemia in NZEO school-aged children and mediated the effect of low selenium on hemoglobin. These findings emphasize the importance of considering multiple micronutrient deficiencies in addition to iron when interpreting anemia and of appreciating the mechanistic interactions that underlie these associations.

Nut consumption is associated with better nutrient intakes: results from the 2008/09 New Zealand Adult Nutrition Survey.

A limited number of studies have examined associations between nut consumption and nutrient intakes or diet quality. None has investigated these associations in the Southern Hemisphere. The purpose of this study was to examine associations between nut consumption and nutrient intakes among adult New Zealanders. Data from the 24-h recalls of 4721 participants from the cross-sectional 2008/09 New Zealand Adult Nutrition Survey (2008/09 NZANS) were used to determine whole nut intake and total nut intake from all sources as well as nutrient intakes. Regression models, both unadjusted and adjusted for potential confounders, were used to estimate differences in nutrient intakes between those consuming and those not consuming nuts. From adjusted models, compared with non-whole nut consumers, whole nut consumers had higher intakes of energy and percentage of energy from total fat, MUFA and PUFA, whereas percentage of energy from SFA and carbohydrate was lower (all P≤0·025). After the additional adjustment for energy intake, whole nut consumers had higher intakes of dietary fibre, vitamin E, folate, Cu, Mg, K, P and Zn (all P≤0·044), whereas cholesterol and vitamin B12 intakes were significantly lower (both P≤0·013). Total nut consumption was associated with similar nutrient profiles as observed in whole nut consumers, albeit less pronounced. Nut consumption was associated with better nutrient profiles, especially a lower intake of SFA and higher intakes of unsaturated fats and a number of vitamins and minerals that could collectively reduce the risk for chronic disease, in particular for CVD.

Cardiorespiratory fitness is positively associated with a healthy dietary pattern in New Zealand adolescents.

OBJECTIVE: To examine the association between cardiorespiratory fitness and dietary patterns in adolescents. DESIGN: Food choice was assessed using the validated New Zealand Adolescent FFQ. Principal components analysis was used to determine dietary patterns. Trained research assistants measured participants' height and body mass. Cardiorespiratory fitness was assessed in a subset of participants using the multistage 20 m shuttle run. The level and stage were recorded, and the corresponding VO2max was calculated. Differences in mean VO2max according to sex and BMI were assessed using t tests, while associations between cardiorespiratory fitness and dietary patterns were examined using linear regression analyses adjusted for age, sex, school attended, socio-economic deprivation and BMI. SETTING: Secondary schools in Otago, New Zealand. SUBJECTS: Students (n 279) aged 14-18 years who completed an online lifestyle survey during a class period. RESULTS: Principal components analysis produced three dietary patterns: 'Treat Foods', 'Fruits and Vegetables' and 'Basic Foods'. The 279 participants who provided questionnaire data and completed cardiorespiratory fitness testing had a mean age of 15·7 (sd 0·9) years. Mean VO2max was 45·8 (sd 6·9) ml/kg per min. The 'Fruits and Vegetables' pattern was positively associated with VO2max in the total sample (ß=0·04; 95%CI 0·02, 0·07), girls (ß=0·06; 95% CI 0·03, 0·10) and boys (ß=0·03; 95% CI 0·01, 0·05). CONCLUSIONS: These results indicate that increase in cardiorespiratory fitness was associated with a healthier dietary pattern, suggesting both should be targeted as part of a global lifestyle approach. Longitudinal studies are needed to confirm this association in relation to health outcomes in New Zealand adolescents.

Serum and erythrocyte folate status of New Zealand women of childbearing age following a countrywide voluntary programme by the baking industry to fortify bread with folic acid.

OBJECTIVE: To estimate the folate status of New Zealand women of childbearing age following the introduction, in 2010, of a new voluntary folic acid fortification of bread programme. DESIGN: The 2011 Folate and Women's Health Survey was a cross-sectional survey of women aged 18-44 years carried out in 2011. The survey used a stratified random sampling technique with the Electoral Roll as the sampling frame. Women were asked about consumption of folic-acid-fortified breads and breakfast cereals in a telephone interview. During a clinic visit, blood was collected for serum and erythrocyte folate measurement by microbiological assay. SETTING: A North Island (Wellington) and South Island (Dunedin) city centre in New Zealand. SUBJECTS: Two hundred and eighty-eight women, of whom 278 completed a clinic visit. RESULTS: Geometric mean serum and erythrocyte folate concentrations were 30 nmol/l and 996 nmol/l, respectively. Folate status was 30-40 % higher compared with women of childbearing age sampled as part of a national survey in 2008/09, prior to the introduction of the voluntary folic acid bread fortification programme. In the 2011 Folate and Women's Health Survey, reported consumption of fortified bread and fortified breakfast cereal in the past week was associated with 25 % (P=0·01) and 15 % (P=0·04) higher serum folate concentrations, respectively. CONCLUSIONS: Serum and erythrocyte folate concentrations have increased in New Zealand women of childbearing age since the number of folic-acid-fortified breads was increased voluntarily in 2010. Consumption of fortified breads and breakfast cereals was associated with a higher folate status.

A profile of New Zealand 'Asian' participants of the 2008/09 Adult National Nutrition Survey: focus on dietary habits, nutrient intakes and health outcomes.

OBJECTIVE: To investigate similarities and differences in dietary habits, nutrient intakes and health outcomes of South Asians (SA) and East and South-East Asians (ESEA) and the New Zealand European and Other (NZEO) group, and to examine differences within 'Asian' subgroups according to duration of residence. DESIGN: Nutrient intake data from 24 h diet recalls and data from the dietary habits questionnaire, anthropometry and biochemical analyses from the cross-sectional 2008/09 Adult National Nutrition Survey in New Zealand were compared for participants categorized as SA, ESEA and NZEO. SUBJECTS: Adults aged 15 years and older (n 2995). SETTING: New Zealand households. RESULTS: SA were more likely to 'never' eat red meat in comparison to NZEO (P<0.001) and among females also in comparison to ESEA (P<0.05). Intakes of fats and some micronutrients (riboflavin, vitamin B6, B12, Se) were lower among SA than NZEO (P<0.05). Lower intakes of Zn and vitamin B12 were reported by SA females compared with ESEA and NZEO females (P<0.05). A higher percentage of SA were obese using ethnic-specific cut-offs, had lower indices of Fe status and reported diagnosed diabetes compared with NZEO and ESEA. Recent SA male migrants had higher intakes of ß-carotene, vitamin C and Ca compared with long-term migrants (P<0.05). CONCLUSIONS: The results of the present study indicate that dietary habits, nutrient intakes, blood profile and body size differ significantly between Asian subgroups. It also provides some evidence for changes in dietary intakes according to duration of residence especially for SA males.

Secular changes in intakes of foods among New Zealand adults from 1997 to 2008/09.

OBJECTIVE: To examine changes in the food choices of New Zealand (NZ) adults, between the 1997 National Nutrition Survey (NNS97) and the 2008/09 NZ Adult Nutrition Survey (2008/09 NZANS). DESIGN: The 2008/09 NZANS and the NNS97 were cross-sectional surveys of NZ adults (aged 15 years and over). Dietary intake data were collected using a computer-based 24 h diet recall. Logistic regression models were used to examine changes over time in the percentage reporting each food group, with survey year, sex and age group (19-30 years, 31-50 years, 51-70 years, ≥71 years) as the variables. SETTING: NZ households. SUBJECTS: Adults aged 19 years and over (NNS97, n 4339; 2008/09 NZANS, n 3995). RESULTS: In the 2008/09 NZANS compared with NNS97, males and females were less likely to report consuming bread, potatoes, beef, vegetables, breakfast cereal, milk, cheese, butter, pies, biscuits, cakes and puddings, and sugar/confectionery (all P<0.001). In contrast, there was an increase in the percentage reporting rice and rice dishes (P<0.001), and among females a reported increase in snacks and snack bars (e.g., crisps, extruded snacks, muesli bars; P=0.007) and pasta and pasta dishes (P=0.017). Although food choices were associated with sex and age group, there were few differential changes between the surveys by sex or age group. CONCLUSIONS: For all age groups there was a shift in the percentage who reported consuming the traditional NZ foods, namely bread, beef, potatoes and vegetables, towards more rice and rice dishes. Declines in the consumption of butter, pies, biscuits, cakes and puddings are congruent with current dietary guidelines.

Diet quality is associated with measures of body fat in adolescents from Otago, New Zealand.

OBJECTIVE: To examine the potential associations between diet quality and multiple measures of body composition in a sample of New Zealand adolescents aged 14-18 years. DESIGN: Cross-sectional survey of eleven high schools in Otago, New Zealand. Each participant completed an online FFQ and a New Zealand Diet Quality Index for Adolescents (NZDQI-A) score was calculated based on variety and adequacy of intake for five major food groups. Besides height and waist circumference measurements, body composition was assessed using segmental bio-impedance analysis. Generalized estimating equations were used to examine associations between diet quality and body composition in models adjusted for sex, age, ethnicity and socio-economic status. SETTING: High schools in Otago, New Zealand. SUBJECTS: High-school students (n 681, 56 % male, mean age 16·1 (sd 1·5) years) participating in the Otago School Students Lifestyle Survey Two. RESULTS: Higher NZDQI-A scores were significantly associated with lower body fat percentage (ß=-0·19; 95 % CI -0·35, -0·04; P=0·014), fat-to-lean mass ratio (ß=-0·26; 95 % CI -0·46, -0·05; P=0·016) and lower fat mass index (ß=-0·23; 95 % CI -0·45, -0·004; P=0·046) after multivariate adjustment. No association was found between NZDQI-A and BMI, waist circumference or waist-to-height ratio. CONCLUSIONS: Diet quality, as measured by NZDQI-A, was associated only with measures of body fat, not measures of overall body size. Measures specific to body fat should be used for more accurate ascertainment of body composition in examining the diet-body composition associations in this age group.

Estimation of serum and erythrocyte folate concentrations in the New Zealand adult population within a background of voluntary folic acid fortification.

National data on the blood folate status of New Zealand adults is lacking. The objective of this study was to describe the blood folate status and examine the predictors of blood folate status in a national sample of adults from New Zealand, a country with voluntary folic acid fortification. The 2008/09 New Zealand Adult Nutrition Survey was a nationwide multistage systematic random cross-sectional survey. Serum and erythrocyte folate concentrations were measured by microbiologic assay. The survey included 4721 participants aged ≥15 y, 3359 of whom provided a nonfasting blood sample. Biochemical folate status was measured in 3277 participants. The median serum and erythrocyte folate concentrations were 23 and 809 nmol/L, respectively. The prevalence of biochemical folate deficiency, defined as plasma folate <6.8 nmol/L or erythrocyte folate <305 nmol/L, was 2%. Having breakfast daily compared with never eating breakfast was associated with 53% higher serum and 25% higher erythrocyte folate concentrations; consumers of fortified yeast extract spread had 17% higher serum and 14% higher erythrocyte folate concentrations than nonconsumers; daily users of folate-containing supplements compared with nonusers had 48% higher serum and 28% higher erythrocyte folate concentrations. The prevalence of biochemical folate deficiency in New Zealand adults is low. Participants who ate breakfast more frequently, consumed folate-fortified yeast, or used a daily folate supplement had higher blood folate concentrations.

Healthy dietary habits score as an indicator of diet quality in New Zealand adolescents.

Adoption of optimal dietary habits during adolescence is associated with better health outcomes later in life. However, the associations between a pattern of healthy dietary habits encapsulated in an index and sociodemographic and nutrient intake have not been examined among adolescents. This study aimed to develop a behavior-based diet index and examine its validity in relation to sociodemographic factors, nutrient intakes, and biomarkers in a representative sample of New Zealand (NZ) adolescents aged 15-18 y (n = 694). A 17-item Healthy Dietary Habits Score for Adolescents (HDHS-A) was developed based on dietary habits information from the 2008/2009 NZ Adult Nutrition Survey. Post hoc trend analyses were used to identify the associations between HDHS-A score and nutrient intakes estimated by single 24-h diet recalls and selected nutritional biomarkers. Being female, not of Maori or Pacific ethnicity, and living in the least-deprived socioeconomic quintile were associated with a higher HDHS-A score (all P < 0.001). HDHS-A tertile was associated positively with intake of protein, dietary fiber, polyunsaturated fatty acid, and lactose and negatively with sucrose. Associations in the expected directions were also found with most micronutrients (P < 0.05), urinary sodium (P < 0.001), whole blood (P < 0.05), serum (P < 0.01), and RBC folate (P < 0.05) concentrations. This suggests that the HDHS-A is a valid indicator of diet quality among NZ adolescents.

Development of a food security measurement tool for New Zealand households.

To determine the prevalence of household food insecurity in New Zealand (NZ), eight food security statements were included in the 1997 National Nutrition Survey of adults. Rasch model analysis was performed to determine whether each food security statement (addressing a food security attribute) was discrete and could be ranked on a unidimensional scale. The NZ model had marginal 'household' reliability (0·60-0·66), good item separation (17·20-17·77) and item infit/outfit values between 0·8 and 1·25. Indices could be ranked by level of severity and represent the experience of household food insecurity in NZ. Categories of food security were assigned and used to predict food choice, and energy and nutrient intakes. Compared with fully secure/almost fully secure households, those that were moderately secure or of low security were less likely to consume the recommended daily servings of fruit and vegetables, and more likely to consume fatty meats. Intake of total fat, saturated, monounsaturated and polyunsaturated fat, cholesterol, lactose and vitamin B12 increased with lower levels of food security. Intakes of glucose, fructose and vitamin C were highest in the fully secure/almost fully secure category. This unique eight-component food security measurement tool has less respondent burden than the US Core Food Security Measure. The relationships between the level of food insecurity and food choice and nutrient intakes illustrate that the most food-insecure households have less healthy diets. This relatively brief population-specific measurement tool is suitable to monitor population food security status, and is a useful marker of nutritional status.

Patterns and predictors of nut consumption: results from the 2008/09 New Zealand Adult Nutrition Survey.

Regular nut consumption is associated with reduced CVD risk. Insight into nut consumption patterns provides important information to help design strategies to encourage intake. The present study aimed to describe nut consumption in terms of the percentage of consumers, mean grams eaten among the population and nut consumers, and to identify the predictors of nut consumption. Data from the 24 h dietary recalls of the 2008/09 New Zealand Adult Nutrition Survey (n 4721) were used to measure nut consumption. On the recall day, the percentages of consumers of whole nuts, nut butters and nuts from hidden sources were 6.9% (n 240), 7.2% (n 346) and 19.2% (n 732), respectively (28.9% (n 1167) combined (total)). The mean grams consumed by the population were relatively low for whole nuts (2.8 g/d), nut butters (0.9 g/d), nuts from hidden sources (1.5 g/d) and total nuts (5.2 g/d). Among consumers, the mean daily grams of whole nuts, nut butters, nuts from hidden sources and total nuts eaten were 40.3, 12.9, 7.8 and 17.9 g/d, respectively. Those aged 15-18 years had the lowest whole nut consumption, but had the highest nut butter consumption. The consumption of total nuts was positively associated with education and socio-economic status, while whole nut consumption was inversely associated with BMI. In conclusion, the low percentage of nut consumers is of concern and new strategies to increase nut consumption are required. Future public health initiatives should be mindful of these patterns and predictors. In particular, different forms of nuts may appeal to different age and socio-economic groups.

Characteristics of fast-food/takeaway-food and restaurant/café-food consumers among New Zealand adults.

OBJECTIVE: To investigate: (i) the percentage of the New Zealand (NZ) population reporting fast food/takeaway food and restaurant/café food per day; (ii) examine demographic factors associated with their use; (iii) quantify their contribution to energy intake; and (iv) describe the specific types of foods reported from both sources. DESIGN: Twenty-four hour diet recalls from the cross-sectional 2008/09 NZ Adult Nutrition Survey were used to identify fast-food and restaurant-food consumers. SETTING: NZ households. SUBJECTS: Adults aged 15 years and older (n 4721). RESULTS: Overall 28 % reported consuming at least one fast food and 14 % a restaurant food within the 24 h diet recall. Fast-food consumption was not associated with level of education or an area-based measure of socio-economic status, but a higher education was positively associated with restaurant-food consumption. Individual factors such as ethnicity, household size, age, sex and marital status were found to be important influences on the use of fast food and restaurant food. Fast-food consumption was more prevalent among participants living in urban areas, young adults (19-30 years) and Maori compared with NZ European and Others. The most frequently reported fast foods were bread-based dishes, potatoes (including fries) and non-alcoholic beverages. CONCLUSIONS: Given the high reported consumption of fast food by young adults, health promotion initiatives both to improve the nutritional quality of fast-food menus and to encourage healthier food choices would likely make a large impact on the overall diet quality of this group.

Dieting status influences associations between dietary patterns and body composition in adolescents: a cross-sectional study.

BACKGROUND: Associations between food choice and body composition in previous studies of adolescents have been inconsistent. This may be due to the body composition measures used, or these associations may be affected by the dieting status of adolescents. The objective of this study was to investigate the association between dietary patterns and body composition in adolescents, and determine if these associations are moderated by dieting status. METHODS: Information on food consumption and current dieting status was collected, using a web-based survey, in 681 adolescents (mean age 15.8 (SD 0.9) years) from schools in Otago, New Zealand. Non-dieters were defined as those reporting not being on a diet as they were "happy with their weight". Principal components analysis (PCA) was used to determine dietary patterns. Body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), fat mass index (FMI), and fat-free mass index (FFMI) were examined as outcomes. Generalized estimating equations were used to examine associations between dietary patterns and body composition. RESULTS: PCA produced three dietary patterns: 'Treat Foods', 'Fruits and Vegetables', and 'Basic Foods'. A standard deviation increase in 'Basic Foods' was associated with a 3.58% decrease in FMI (95%CI -6.14, -0.94) in the total sample. When separate sex analysis was undertaken significant negative associations were found in boys only, between the 'Basic Food' score and WC, WHtR, FMI, and FFMI, while the 'Fruits and Vegetables' pattern was negatively associated with FMI. Associations between 'Treat Foods' and BMI, WC, and WHtR in non-dieters were positive, while these associations were negative for all other participants. CONCLUSIONS: Significant associations were found between dietary patterns and indices of both central and total adiposity, but not BMI. Therefore using only BMI measures may not be useful in this age group. Since our results were significant for boys and not girls, nutrition messages designed to prevent obesity may be particularly important for adolescent boys. As an interaction between dieting status and 'Treat Foods' existed, future studies should also explore the role of dieting when investigating food choice and body composition.

Providing additional money to food-insecure households and its effect on food expenditure: a randomized controlled trial.

OBJECTIVES: Financial constraint is the underpinning determinant of household food insecurity; however, there has been little research examining the impact that increasing the 'money available' to food-insecure households could have on food purchasing. The main objective of the present study was to examine the effect of additional money (in the form of supermarket vouchers) on food expenditure in food-insecure households with children. DESIGN: A parallel randomized controlled trial with a 4-week baseline phase followed by a 4-week intervention phase. Households were randomized to either receive vouchers (coupons) for 4 weeks or a control group that did not receive any vouchers. SETTING: Dunedin, New Zealand. SUBJECTS: Low-income households with children ≥ 18 years) reporting food insecurity (n 214). RESULTS: The mean monetary value of the vouchers received by households was $NZ 17?00 per week. The voucher group spent ≥ NZ 15.20 (95% CI 1.46, 28.94) more per week on food during the intervention phase compared with the control group (P50.030). There were no differences in expenditure between the voucher and the control group for the food groups 'fruit and vegetables' (mean difference: ≥ NZ 0?46; 95% CI 21.97, 2.89; P50.709), 'meat and poultry' (mean difference: ≥ NZ 0.29; 95% CI 23.07, 3.64; P50.866) and 'dairy' (mean difference: ≥ NZ 0.82; 95% CI 20.75, 2.42; P50.302). CONCLUSIONS: Providing money via supermarket vouchers to food-insecure resulted in an increase in overall expenditure on food.

Attitudes to food differ between adolescent dieters and non-dieters from Otago, New Zealand, but overall food intake does not.

OBJECTIVE: There is increasing pressure for adolescents to be thin and this may not always be acted upon in healthy ways; for example, certain foods or food groups may be restricted or meals skipped. As foods are not eaten in isolation it is useful to examine dietary patterns and associated psychosocial factors to better understand eating behaviour. The aim of the present study was to identify correlates of 'dieting' in adolescents from Otago, New Zealand. DESIGN: A web-based survey was conducted in 2009, collecting information on food consumption and factors potentially associated with food consumption. Principal components analysis was used to investigate dietary patterns. Correlates were examined in 1329 students using multiple logistic regression analysis. SETTING: Nineteen secondary schools in the province of Otago, New Zealand. SUBJECTS: Students from school years 9 and 10 (mean age 14.1 (SD 0.7) years). RESULTS: There was no relationship between dieting and dietary patterns. Those not dieting were 17 % (95 % CI 7, 26 %) more likely to eat lunch and 22 % (95 % CI 3, 37 %) more likely to eat an evening meal on one more weekday than those who were dieting. Those who reported dieting were more likely to report healthiness (OR = 2.18, 95 % CI 1.11, 4.26) as an important factor when choosing food and that eating fruit and vegetables makes you better looking. No sex by dieting interaction was found. CONCLUSIONS: In this cohort, while there was no difference in actual food consumption between dieters and non-dieters, there were significant differences in attitudes to food.

Development and validation of a food-based diet quality index for New Zealand adolescents.

BACKGROUND: As there is no population-specific, simple food-based diet index suitable for examination of diet quality in New Zealand (NZ) adolescents, there is a need to develop such a tool. Therefore, this study aimed to develop an adolescent-specific diet quality index based on dietary information sourced from a Food Questionnaire (FQ) and examine its validity relative to a four-day estimated food record (4DFR) obtained from a group of adolescents aged 14 to 18 years. METHODS: A diet quality index for NZ adolescents (NZDQI-A) was developed based on 'Adequacy' and 'Variety' of five food groups reflecting the New Zealand Food and Nutrition Guidelines for Healthy Adolescents. The NZDQI-A was scored from zero to 100, with a higher score reflecting a better diet quality. Forty-one adolescents (16 males, 25 females, aged 14-18 years) each completed the FQ and a 4DFR. The test-retest reliability of the FQ-derived NZDQI-A scores over a two-week period and the relative validity of the scores compared to the 4DFR were estimated using Pearson's correlations. Construct validity was examined by comparing NZDQI-A scores against nutrient intakes obtained from the 4DFR. RESULTS: The NZDQI-A derived from the FQ showed good reliability (r = 0.65) and reasonable agreement with 4DFR in ranking participants by scores (r = 0.39). More than half of the participants were classified into the same thirds of scores while 10% were misclassified into the opposite thirds by the two methods. Higher NZDQI-A scores were also associated with lower total fat and saturated fat intakes and higher iron intakes. CONCLUSIONS: Higher NZDQI-A scores were associated with more desirable fat and iron intakes. The scores derived from either FQ or 4DFR were comparable and reproducible when repeated within two weeks. The NZDQI-A is relatively valid and reliable in ranking diet quality in adolescents at a group level even in a small sample size. Further studies are required to test the predictive validity of this food-based diet index in larger samples.

A comprehensive assessment of urinary iodine concentration and thyroid hormones in New Zealand schoolchildren: a cross-sectional study.

BACKGROUND: Insufficient iodine in children's diets is of concern because thyroid hormones are needed for normal growth and development, particularly of the brain. This study aimed to carry out a comprehensive assessment of the iodine status of New Zealand schoolchildren using a range of biochemical indices suitable for populations (i.e. urinary iodine concentration) and individuals (i.e. thyroid hormones). METHODS: The New Zealand National Children's Nutrition Survey was a cross-‒sectional survey of a representative sample of schoolchildren aged 5-‒14 years. Children were asked to provide a casual urine sample for the determination of urinary iodine concentration (UIC) and a blood sample for the determination of thyroglobulin (Tg), Thyroid Stimulating Hormone (TSH), free thyroxine (fT4) and free triiodothyronine (fT3). RESULTS: The median UIC was 68 µg/L (n = 1153), which falls between 50-‒99 µg/L indicative of mild iodine deficiency. Furthermore, 29% of children had an UIC <50 µg/L and 82% had an UIC <100 µg/L. The median Tg concentration was 12.9 µg/L, which also falls between 10.0-‒19.9 µg/L indicative of mild iodine deficiency. The Tg concentration of children with an UIC <100 µg/L was 13.9 µg/L, higher than the 10.3 µg/L in children with an UIC >100 µg/L (P = 0.001). The mean TSH (1.7 mU/L), fT4 (14.9 pmol/L), and fT3 (6.0 pmol/L) concentrations for these mildly iodine deficient New Zealand children fell within normal reference ranges. CONCLUSIONS: The UIC and Tg concentration indicate that New Zealand schoolchildren were mildly iodine deficient according to WHO/UNICEF/ICCIDD, and both are suitable indices to assess iodine status in populations or groups. The normal concentrations of TSH, fT4 and fT3 of these children suggest that these thyroid hormones are not useful indices of mild iodine deficiency.

Reliability and relative validity of a food frequency questionnaire to assess food group intakes in New Zealand adolescents.

BACKGROUND: Due to the absence of a current and validated food frequency questionnaire (FFQ) for use in New Zealand adolescents, there is a need to develop one as a cost-effective way to assess adolescents' food patterns. This study aims to examine the test-retest reliability and relative validity of the New Zealand Adolescent FFQ (NZAFFQ) to assess food group intake in adolescents aged 14 to 18 years. METHODS: A non-quantitative (without portion size), 72-item FFQ was developed and pretested. Fifty-two participants (aged 14.9 ± 0.8 years) completed the NZAFFQ twice within a two-week period for test-retest reliability. Forty-one participants (aged 15.1 ± 0.9 years) completed a four-day estimated food record (4DFR) in addition to the FFQs to enable assessment of validity. Spearman's correlations and cross-classification analyses were used to examine relative validity while intra-class correlations were additionally used for test-retest reliability. RESULTS: Weekly intakes were estimated for each food item and aggregated into 34 food groups. The median Spearman's correlation coefficient (SCC) between FFQ administrations was 0.71. SCCs ranged from 0.46 for fruit juice or cordial to 0.87 for non-standard milk. The median intra-class correlation coefficient (ICC) between FFQ administrations was 0.69. The median SCC between food groups from the FFQ and the 4DFR was 0.40 with the highest SCC seen for standard milk (0.70). The exact agreement between the methods in ranking participants into thirds was highest for meat alternatives (78%), but lowest for red or yellow vegetables and potatoes (27%). The mean percent of participants misclassified into extreme thirds for food group intake was 12%. CONCLUSIONS: Despite a small sample size, the NZAFFQ exhibited good to excellent short-term test-retest reliability and reasonable validity in ranking the majority of the food group intakes among adolescents aged 14 to 18 years. The comparability of the validity to that in the current literature suggests that the NZAFFQ may be used among adolescent New Zealanders to identify dietary patterns and rank them according to food group intake.

Higher risk of zinc deficiency in New Zealand Pacific school children compared with their Maori and European counterparts: a New Zealand national survey.

Few multi-ethnic national surveys have examined Zn nutriture, despite its importance for optimal growth and development during childhood. We assessed the Zn status of urban and semi-urban children aged 5-15 years from three ethnic groups in New Zealand (NZ) in the 2002 Children's National Nutrition Survey and investigated the factors predisposing them to Zn deficiency. In a 10-month cross-sectional survey, Pacific and Maori children were over-sampled permitting ethnic-specific analyses. Anthropometry, serum Zn and Zn intakes via 24 h recalls were measured. Anthropometric z scores were highest in Pacific children. Overall, mean adjusted serum Zn at 11 years was for males and females, respectively: 11·9 (95% CI 11·5, 12·3) and 12·5 (95% CI 12·0, 12·9) µmol/l in NZ European and Other (NZEO) children (n 395); 11·9 (95% CI 11·4, 12·4) and 12·0 (95% CI 11·4, 12·5) µmol/l in Maori children (n 379); and 11·5 (95% CI 11·1, 11·9) and 11·4 (95% CI 11·1, 11·8) µmol/l in Pacific children (n 589). The predictors of serum Zn were age, serum Se and sex for NZEO children; serum Se and age for Pacific children; and none for Maori children. Pacific children had the highest prevalence of low serum Zn (21 (95% CI 11, 30) %), followed by Maori children (16 (95% CI 12, 20) %) and NZEO children (15 (95% CI 9, 21) %). Prevalence of inadequate Zn intakes, although low, reached 8% for Pacific children who had the lowest Zn intake/kg body weight. Pacific boys but not girls with low serum Zn had a lower mean height-for-age z-score (P < 0·007) than those with normal serum Zn. We conclude that the biochemical risk of Zn deficiency in Pacific children indicates a public health problem. However, a lack of concordance with the risk of dietary Zn inadequacy suggests the need for better defined cut-offs in children.

What children eat during afternoons and evenings: is it important?

OBJECTIVE: To complete a description of the dietary intakes of New Zealand schoolchildren by describing afternoon and evening foods and nutrients. DESIGN: Twenty-four hour dietary recall data from the 2002 Children's Nutrition Survey were analysed to describe food and nutrient intakes during the afternoon (14.00 to 16.59 hours) and evening (17.00 to 23.59 hours). SETTING: New Zealand homes and schools. SUBJECTS: Children (n 2875) aged 5-14 years. RESULTS: Most children consumed something during the afternoon (79 %) and evening (98 %). Children were less likely to consume something during non-school day afternoons; if 11-14 years of age; and when of Pacific ethnicity. Afternoon food consumers had higher daily intakes for most nutrients. Afternoon intake accounted for much of this difference. In the afternoon, children consumed fruit (26 %) and biscuits/crackers (21 %). Evening eating contributed to daily intakes of energy (40 %), fat (43 %), carbohydrate (35 %), sucrose (20 %), glucose (24 %), vitamin A (47 %), Ca (26 %) and Fe (40 %). Children aged 5-6 years consumed a lower proportion of their daily energy intake during the evening than older children. In the evening, just one-third of children consumed vegetables (45 % if including potato/kumara/taro), 19 % fruit and 17 % ate hot chips. Children were more likely to consume vegetables if they also consumed potato/kumara/taro. Twenty-three per cent of children had powdered drinks/cordials, 21 % had soft drinks and 19 % had milk. CONCLUSIONS: Consuming foods/drinks in the afternoon positively influenced macronutrient distribution, increasing the carbohydrate proportion. During the evening 40 % of energy intake was consumed but less than one-half of children consumed vegetables; thus inclusion of vegetables in the evening is important, particularly in meals without potato/kumara/taro.