Winsome R. Parnell

A Longitudinal Study of Breastfeeding and Weaning Practices During the First Year of Life in Dunedin, New Zealand

OBJECTIVE To investigate infant feeding practices during the first year of life in a group of white infants in Dunedin, New Zealand. DESIGN Prospective study of infants from birth to 12 months of age. PARTICIPANTS A self-selected sample of 74 white mothers and their infants born in Dunedin, New Zealand, between October 1995 and May 1996. Statistical analyses Regression analyses were performed to determine factors associated with successful breastfeeding initiation and duration. RESULTS Among mothers, 88% (n=65) initiated breastfeeding, 42% (n=31) were exclusively breastfeeding at 3 months, and 34% (n=25) were partially breastfeeding at 12 months. Intention to breastfeed increased the likelihood of successful breastfeeding initiation. Mothers who reported that they did not have enough breastmilk tended to exclusively breastfeed for a shorter period of time. Tertiary education and exclusively breastfeeding at 1 month were associated with a longer duration of breastfeeding. Perception of breastfeeding in public as embarrassing was associated with a shorter duration of breastfeeding. Among infants, 45% (n=33) were given nonmilk foods before 4 months of age, and 69% (n=51) were given unmodified cows milk as a beverage before 12 months. APPLICATIONS Breastfeeding rates in this study, although higher than in many Western countries, were still lower than current recommendations. Our findings suggest that women should be taught how to increase their breastmilk supply. Parents should also be informed of the importance of delaying the introduction of nonmilk foods until their infant is 4 to 6 months of age and cows milk until they are 12 months of age. Society also needs to address the social issue of embarrassment many mothers feel when breastfeeding in public.

Dietary intakes of 6-24-month-old urban South Island New Zealand children in relation to biochemical iron status.

OBJECTIVE To investigate food sources and intakes of iron, and dietary factors associated with serum ferritin levels in 6-24-month-old children. DESIGN A cross-sectional survey employing proportionate cluster sampling was conducted in 1998/1999. Dietary intakes were assessed using a non-consecutive 3-day weighed food record. Serum ferritin and C-reactive protein were analysed from non-fasting venepuncture blood samples and general sociodemographic data were collected. SETTING Cities of Christchurch, Dunedin and Invercargill, New Zealand. SUBJECTS Randomly selected healthy 6-24-month-old non-breast-feeding children (n = 226). RESULTS Total iron intakes (+/- standard deviation (SD)) among non-breast-feeding infants (< 12 months old; n = 42) and toddlers (> or = 12 months old; n = 184) were 8.4 +/- 2.9 mg day(-1) and 5.0 +/- 2.5 mg day(-1), respectively. Fifteen per cent of infants and 66% of toddlers were at risk of inadequate iron intakes. Main sources of dietary iron were infant formula (60%) for infants and cereals (31%) for toddlers. Meat contributed on average 2% and 10% of dietary iron in the infant and toddler diets, respectively. Dietary factors positively associated with serum ferritin were intakes of iron and vitamin C, whereas intakes of calcium and dietary fibre were negatively associated. For each 1% increase in percentage of energy from iron-fortified formula concomitant with a 1% decrease from dairy products, there was a 4.2% increased odds of replete iron stores (ferritin > or = 20 microg l(-1)). CONCLUSIONS Toddlers were at higher risk of sub-optimal iron intakes than infants. Results suggest that a diet high in bioavailable iron is important for optimising the iron stores of young children in New Zealand.

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

BackgroundDue 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.MethodsA 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.ResultsWeekly 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%.ConclusionsDespite 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.

Exploring the relationship between sugars and obesity.

OBJECTIVE Investigate the relationship between body mass index (BMI) and intake of sugars and fat in New Zealand adults and children. DESIGN Secondary analyses of National Nutrition Survey (1997) and Childrens Nutrition Survey (2002) data for the New Zealand population. BMI calculated from height and weight; fat, sugars and sucrose (used as a surrogate for added sugars) intakes estimated from 24-hour diet recall. Ethnic-specific analyses of childrens data. Relationships (using linear regression) between BMI and sugars/sucrose intakes; per cent total energy from fat; mean total energy intake from sucrose. Subjects classified into diet-type groups by levels of intake of fat and sucrose; relative proportions of overweight/obese children in each group compared with that of normal weight subjects using design-adjusted chi2 tests. SETTING New Zealand homes and schools. SUBJECTS 4379 adults (15+ years); 3049 children (5-14 years). RESULTS Sugars (but not sucrose) intake was significantly lower among obese compared to normal weight children. In adults and children, those with the lowest intake of sugars from foods were significantly more likely to be overweight/obese. Sucrose came predominantly from beverages; in children, 45% of this was from powdered drinks. Sucrose intake from sugary beverages was not related to BMI. Per cent total energy (%E) from sucrose was significantly inversely related to %E from fat among adults and children. Proportions of overweight/obese adults or children in each diet-type group did not differ from that of normal weight individuals. CONCLUSIONS Current sugars or sucrose intake is not associated with body weight status in the New Zealand population.

Serum selenium concentrations and dietary selenium intake of New Zealand children aged 5-14 years

Serum Se concentrations and dietary Se intakes have been determined in relation to age, sex, ethnicity, region and index of deprivation in a nationally representative sample of New Zealand children aged 5-14 years from the 2002 National Childrens Nutrition Survey. Dietary intake was assessed from computer-assisted, multiple-pass 24 h diet recall interviews (n 3275). Serum Se concentrations were obtained from a subset of urban-based children (n 1547). Mean (95 % CI) serum Se concentration in children was 0.96 (0.93, 1.00) micromol/l. Males (1.00 micromol/l) had higher serum Se levels than females (0.93 micromol/l; P = 0.027). Mäori children had lower serum Se than Pacific Islands children (P = 0.038) and New Zealand European and Other children (P = 0.005). Children in the Upper North Island (1.06 micromol/l) had higher mean serum Se values than those in the Lower North Island (0.98 micromol/l, P < 0.0005) and South Island (0.79 micromol/l, P < 0.0005), and serum Se in the Lower North Island was higher than that in the South Island (P < 0.0005). Mean dietary Se intake was 36 (34, 37) microg/d. The intakes of children aged 5-6 years (31 microg/d) were lower than those of children aged 7-10 and 11-14 years (35 and 38 microg/d, respectively; P < 0.00 005) and the intakes of 7-10-year-olds were lower than those of 11-14-year-olds (P = 0.002). Serum Se was associated with dietary Se after adjusting for all variables, including region (P = 0.006). The Se status of our children falls in the middle of the international range of serum Se concentrations, but that for children in the South Island is among the lowest values reported and may be a cause for concern.

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

BackgroundAssociations 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.MethodsInformation 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.ResultsPCA 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.ConclusionsSignificant 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.

Higher risk of zinc deficiency in New Zealand Pacific school children compared with their Māori 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 Childrens National Nutrition Survey and investigated the factors predisposing them to Zn deficiency. In a 10-month cross-sectional survey, Pacific and Māori 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 Māori 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 Māori children. Pacific children had the highest prevalence of low serum Zn (21 (95% CI 11, 30) %), followed by Māori 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.

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

Nutrients and foods consumed by New Zealand children on schooldays and non-schooldays.

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.

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

OBJECTIVE To describe and compare food and nutrient intakes in New Zealand (NZ) children on schooldays and non-schooldays. DESIGN Secondary analysis of cross-sectional data from the NZ 2002 Childrens Nutrition Survey. Dietary intake was assessed using computer-assisted multi-pass 24 h dietary recalls in the home. Data were adjusted for survey weightings to be representative of the NZ population. The effect of day category on nutrient intake, and likelihood of consumption of food categories were determined using linear and logistic regression. SETTING NZ homes and schools. SUBJECTS A total of 2572 children (538 non-schooldays and 2034 schooldays) at the age of 5-14 years. RESULTS There were differences in the proportion consuming some food groups between schooldays and non-schooldays, although the majority of nutrient intakes including energy did not differ by day category. Mean cholesterol intake was higher on non-schooldays; dietary fibre and available carbohydrate, in particular sucrose and fructose, were higher on schooldays. Hot chips were twice as likely to be consumed on a non-schoolday. Soft drink consumption was higher on non-schooldays for Māori/New Zealand European and others and powdered drinks/cordial consumption did not vary by day category. More children consumed snack bars (normal weight, obese), fruit, sandwiches, biscuits/crackers and snack foods on schooldays. There was no difference in consumption of pies/sausage rolls by day category. CONCLUSIONS The proportion of consumers of a variety of foods differed significantly between non-schooldays and schooldays; few nutrient intakes differed. The present study indicates that family food, wherever it is consumed, is the mainstay of nutrition for NZ schoolchildren.