Search

Current statistical methods of disaggregating populations by ethnic or cultural identity wrongly assume cultural invariance within an ethnic population over time and place. Calculating risk factors between ethno-cultural populations also wrongly assumes homogeneity of risk, obscuring what may be distinct sub-populations with very different demographics, risk profiles, and health outcomes. The Cultural Cohort Approach (CCA) proposes a novel method for understanding within-ethnic population difference, whereby cultural identity is framed as the enduring membership of multiple related cultural cohorts, rather than the contextual and unstable measure of ethnic group affiliation currently used. It predicts that multiple cultural cohorts exist inside an ethno-cultural population, that these cultural cohorts are resilient and culturally distinct, exist over generations, and can divide at pre-existing social or economic stratifications in response to powerful external forces. The cultural cohort approach unites history, extant identity theories and research to identify and describe these within-ethnic cultural cohorts. The measurement of a Māori cultural cohort joins existing Māori identity research, historical documents, and personal accounts to enumerate distinct Māori cultural cohorts, describe relationships between cultural cohorts, and exclude unrelated cultural cohorts. Across three distinct components of this thesis the Cultural Cohort Approach (CCA) is first described and a worked example of its use in identifying Māori cultural cohorts given. Second, these hypothesised cultural cohorts were mapped to a cross-sectional data collection wave of Māori participants (n=3287, born between 1941 and 1955) from Massey University’s longitudinal Health, Work and Retirement (HWR) study in a test of the CCA’s predictive accuracy using latent class analysis. Third, longitudinal HWR study data for Māori participants (n=1252, born between 1941 and 1955) was used in a second worked

Background: Describing the effect of the diet on obesity risk as simply excessive energy intake, does not factor in the patterning (spacing, skipping and timing), or format (food combinations and nutrient content) of meals consumed or the specific eating behaviours that contribute to weight gain. In addition to this, chronotype, may also play a role in the complex aetiology of obesity. Being a very late (=evening type, ET) or early chronotype (=morning type, MT) not only determine preferred sleep- and wake-times but may also influence mealtimes, nutritional composition of meals and eating behaviour. This may impact the circadian timing system and in the long-term, result in weight gain, obesity, and poor metabolic function. Aims: To explore the diet in-depth (eating patterns and eating behaviours) as it relates to different chronotypes and metabolic health markers of New Zealand (NZ) European and Pacific women with different body fat profiles and varied metabolic disease risk factors. Methods: This research formed part of the PRedictors linking Obesity and gut Microbiome (PROMIsE) cross-sectional study that was conducted at the Massey University in Auckland, NZ. Healthy women, between the ages of 18 and 45 years were recruited based on healthy BMI (18.5 -24.9 kg/m²) and obese BMI (≥30 kg/m²) within NZ European (n = 162) and Pacific (n = 142) ethnic groups. Chronotype, was assessed using the Munich Chronotype Questionnaire. Fasting venous blood samples were collected to assess metabolic biomarkers (hormones, lipid profile and glucose homeostasis). Anthropometrical measurements included, body mass index (BMI), and whole-body total fat percentage (BF%), android-and gynoid- fat mass were assessed using dual-energy x-ray absorptiometry. Five-day food records were used to assess dietary intake. The Three Factor Eating Questionnaire and the Eating Attitude Test -26 was used to assess eating behaviour and - attitudes. Results: Half of participants were intermediate type (IT

Both adolescent and athlete populations have been identified as at-risk groups when it comes to sleep timing, duration and quality. The aetiology of sleep issues within these populations is disparate, leading to the question of whether adolescent athletes are at particular risk considering that they span both groups. Few studies, however, have investigated the sleep patterns and behaviours of elite adolescent athletes during their everyday lives. Fewer still have attempted to intervene to improve sleep/wake patterns and behaviour where sleep concerns have been identified within adolescent athlete cohorts. This thesis comprised two studies, the first with a group of elite adolescent swimmers and the second with rowers. Swimmers and rowers were chosen as both sporting codes have traditionally high early morning training demands. Early morning training has been identified as a predominant driver of sleep loss for athlete groups making these cohorts of particular interest. Both studies included baseline monitoring for two weeks to identify the athletes’ typical sleep patterns during a normal training phase that took place during the school term. Following baseline, both athlete groups received educational training on sleep with specific sleep advice being tailored to each group using data gathered during baseline. In addition to the sleep educational material, the swimmers also had one of their early morning training sessions moved to another day of the week to try and provide them with consecutive days free of early morning training while the rowers received blue light-blocking glasses to try to limit night-time exposure to blue light. Baseline data from both groups revealed that sleep timing as well as sleep duration varied significantly across the days of the week. Sleep duration was significantly truncated on school nights before early morning training (6.7 hours) compared to school nights before mornings without training (8.8 hours). The curtailed sleep was linked

Background: Ageing and obesity, which impair muscle protein synthesis (MPS), are associated with muscle mass and muscle strength loss in older adults. It is recognised that adequate protein intake, distribution and sources contribute to increased MPS and muscle mass in older adults. However, little is known about protein intake, distribution, and sources in New Zealand (NZ) older adults. Furthermore, it is unclear whether dietary protein influences muscle strength. Objectives: This thesis explored muscle strength, muscle mass and dietary protein intake, distribution and sources in community-dwelling older adults living in NZ. To meet this objective, the role of obesity in the relationship between muscle mass and muscle strength was examined. This was followed by an investigation of protein intake, distribution and sources, and their association with muscle strength. Methods: Data were obtained from the Researching Eating Activity and Cognitive Health (REACH) study, a cross-sectional study aimed at investigating dietary patterns and associations with cognitive function and metabolic syndrome in older adults aged 65 to 74 years. Isometric grip strength was measured using a hand grip strength dynamometer (JAMAR HAND). Body fat percentage and appendicular skeletal muscle mass (ASM) (sum of lean mass in the arms and legs) were assessed using dual-energy X-ray absorptiometry (Hologic, QDR Discovery A). The ASM index was calculated by ASM (kilograms, kg) divided by height (meters, m) squared. Dietary intake was collected using a 4-day food record, and the data was entered into FoodWorks 10. Data on absolute daily protein intake (grams, g) were generated. According to the peaks of protein consumption throughout the day, days were divided into three meals: breakfast, mid-day, and the evening meals. Protein sources were classified as meat and fish; plant; or dairy and egg protein sources based on the primary type of protein found in food. The relative protein intakes (g/kg) p

Background: Basic training for military recruits is a physically demanding course that is generally a sudden change from an individual’s habitual lifestyle. Female recruits have physiological disadvantages in comparison to males, which contribute to lower aerobic fitness and higher risk of musculoskeletal injuries. Nutrition related health, including iron and vitamin D status, dietary intake and body composition is essential to support the health and physical fitness of female recruits. However, little is known about how these nutrition related health factors change during completion of basic training, their determinants or associations with measures of physical fitness in female recruits in the New Zealand Army. Objectives: The objectives of this research in females undertaking 16-weeks of basic training in the New Zealand Army were to 1) characterise iron status in female recruits during basic training and investigate associations with physical fitness; 2) investigate associations between iron stores, dietary patterns and non-dietary determinants of iron stores in female recruits at the commencement of basic training; 3) characterise vitamin D status in female recruits during basic training and investigate potential determinants at the commencement of basic training; and 4) characterise body composition, physical fitness and dietary intake during basic training and investigate associations between these three factors in female recruits. Methods: Data were collected at weeks 1 and 16 of basic training from female recruits who enlisted in the New Zealand Army between February 2014 and March 2016. Demographic, lifestyle and medical history information were self-reported via an online questionnaire at week 1. Dietary intake data from a food frequency questionnaire (FFQ) administered online and body composition measurements were collected at weeks 1 and 16. Body composition was determined by the InBody230 bioelectrical impedance analyser and included body mass (BM), sk

Jockeys work at close to their physiological capacity during a race. However, despite the pivotal role of the jockey in the success of racing, there are limited data published on the physiological challenges of race riding and the influence of muscular fatigue on the jockeys during a race and over their careers. Until the sport-specific physiological demands of race riding are quantified, the development of evidence-based sport specific and potentially performance enhancing jockey training programmes cannot be realised. Successful training interventions require knowledge of the physiological demands and performance characteristics of the specific sport. Therefore, the aims of this thesis were to characterise the injury risk, performance and career longevity of jockeys in relation to their overall and specific, training and competition level physiological demands. Using race-day records of 786 jockeys riding over 14 years (2005 – 2019) of Thoroughbred racing in New Zealand (n = 421,596 starts), descriptive statistics, uni- and multi- variable analyses and Kaplan Meier survival curves, it was determined that jockeys with higher competitive workloads performed better, had fewer falls and longer careers than those with lower competitive workloads. A nationwide online survey completed by 40% of the jockey population in New Zealand identified that the main form of exercise for jockeys was riding in training and racing. This indicated that jockeys with higher competitive workloads may have a greater degree of sport specific fitness from regular competitive riding that jockeys with lower workloads (or apprentice jockeys beginning their career) are unable to gain through simply riding track-work and trial rides. The ride specific physiological demands, body displacements and muscle activities of jockeys were determined by instrumenting jockeys with heart rate (HR) monitors, global positioning system (GPS), accelerometers (body displacement) and electromyographic clothing (re

Climate change continues to expose an increasing proportion of the global population to more frequent extreme heat events. Concurrently, our society has seen an increase in the number of women that participate in physically demanding leisure time (exercise and sport) and occupational activity. Yet, limited research has been conducted to understand the female physiological responses to exercise-heat stress, especially when considering their various ovarian hormone profiles. This thesis expands our understanding of the female physiological responses to heat stress from different perspectives. Firstly, previous evidence has demonstrated that ambient heat stress amplifies the increase in the cytokine interleukin-6 following exercise, an up-regulator of hepcidin - the hormone that downregulates iron metabolism. In Chapter Five iron sufficient females’ serum iron parameters and hepcidin levels following a self-paced cycling work trial were compared in temperate and hot conditions, and different menstrual phases. IL-6 and hepcidin both increased post-exercise (198% and 38%, respectively), interestingly, neither were affected by ambient temperature or menstrual phase (all p>0.15). Chapter Six determined the measurement error of a 30-min self-paced cycling protocol in moderate, warm-dry and warm-humid environments using thirty-three athletic women distinguished by their ovulatory status and ovarian hormone concentrations. With an ICC=0.90, p<0.01, and a mean CV of 4.7%, SEM of 3.8 kJ (2.1 W) and reliable bias of -2.1 kJ (-1.2 W), it was confirmed that this protocol has high test-retest reproducibility that is not influenced by ambient environment or a female’s hormonal/ovulatory status. Finally, in order to better predict females’ risk for exertional heat stress, Chapter Seven attempted to clarify the role of the ovarian hormones when explaining the variance of the core temperature response using the 30-min self-paced cycling protocol from Chapter Six in thirty-six trained w

The persistence of Māori health inequities, exacerbated by deficit narratives, underscores the importance of conducting research on the strengths and capabilities whānau possess and use in their daily lives in order to actively rethink and redesign health promotion practice in Aotearoa New Zealand in a way that will be beneficial for whānau. Focusing on health promotion within an Indigenous context, this thesis synthesises results from three case studies about whānau-centred initiatives where Māori (Indigenous to New Zealand) values and practices are foundational. A kaupapa whānau research framework, developed in collaboration with whānau, draws on mātauranga (Māori epistemologies/ways of knowing) expressed in pūrākau (epistemological narratives), tikanga (cultural principles), te reo (Māori language), and lived experience, which serve as the foundation for the methodology employed in this research. The findings illustrate the diversity and potential capabilities of whānau-centred initiatives in addressing Māori health inequities, emphasising the critical role of whānau in improving Māori health and wellbeing. A conceptual framework, Tū Kahikatea, is developed to present findings demonstrating the connection between the values underpinning the initiatives and their outcomes. Furthermore, the framework emphasises how whānau-centred initiatives can aid whānau in achieving mana motuhake (mana achieved through collective self-determination and control over one’s own destiny). Consistent with an Indigenous approach to health promotion, this research indicates that health promotion activities that take into account Māori worldviews and values, as well as those generated within Māori communities, will have a greater influence on Māori health outcomes than programmes that take a top-down, single issue approach to health promotion. As part of a global movement for more inclusive healthcare that prioritises Indigenous voices and knowledge systems, this research bridges the ga

Palestinian refugees at long-term Lebanese camps are at increased anaemia risk. Adolescent Palestinians at these camps, with their disproportionately high poverty burdens, are at particular risk, though little-to-no data are available to describe this. Anaemia in Lebanon has been attributed, largely, to inadequate intake of bioavailable iron. This may occur when a population is reliant on non-haem iron food sources to meet nutrient needs, as is often the case in long-term camp settings. No studies are currently available that describe adolescent Palestinian diets at Lebanese camps. There is also a dearth of studies exploring food preparation practices that may be harnessed to optimise iron bioavailability from consumed foods at these camps. This study used an embedded mixed-methods design to evaluate anaemia prevalence, iron source food consumption, and micronutrient dietary diversity (DDS-M) for a group of adolescent Palestinians (n = 66) at the Beddawi refugee camp in North Lebanon. The study also explored household plant-food use and preparation, with particular reference to dark leafy greens, and plant-food valuation with household food preparers (FPs). Anaemia prevalence for adolescents was 29%. Median DDS-M was 4 [IQR = 1.63, range = 2-6]. Grain-based foods were consumed by the largest proportion of adolescents (100%), followed by milk source foods (84.8%) and fruits (59.1%). Jute mallow, chicory, parsley and spinach were the dark leafy greens used by the largest proportions of households (> 80%). Household use of a subset of dark leafy greens was positively associated with adolescent DDS-M (rho = 0.31, S = 14303, p-value = 0.03). All FPs reported plant food valuation; however, FPs in households with non-anaemic adolescents related plant food valuation responses with more detailed nutrient and health rationales than FPs in households with anaemic adolescents. Lemon juice, capsicum and chilli were among foods commonly reported to be co-consumed with plant meals

Fumigants are widely used in shipping containers and on export logs for biosecurity reasons. This thesis aimed to: (i) assess concentrations of fumigants and off-gassed chemicals in closed containers; (ii) identify container characteristics associated with high concentrations; (iii) assess personal exposure levels of workers exposed to these chemicals; and (iv) assess whether exposed workers report more neuropsychological symptoms. Air samples were collected from 490 sealed containers and at opening of 46 containers, and 193 personal full-shift air samples were collected for 133 container handlers, 15 retail workers, 40 workers loading export logs, and 5 fumigators. Samples were analysed by Selected Ion Flow Tube Mass Spectrometry for several common fumigants and harmful chemicals frequently found in shipping containers. Levels were compared to the New Zealand Work Exposure Standard (WES) and the Threshold Limit Value (TLV). A neuropsychological symptom questionnaire was completed by 274 container handlers, 38 retail workers, 35 fumigators, 18 log workers, and a reference group of 206 construction workers. Fumigants were detected in 11.4% of sealed containers (ethylene oxide 4.7%; methyl bromide 3.5%). Chemicals other than fumigants were detected more frequently, particularly formaldehyde (84.7%). Some cargo types (e.g. rubber products) and countries of origin (e.g. China) were associated with higher chemical concentrations. Fumigants were detected in both fumigated and non-fumigated containers. Ambient chemical concentrations in closed and just opened containers regularly exceeded the NZ WES and TLV. Personal exposure measurements never exceeded the NZ WES, although for 26.2% of samples the TLV for formaldehyde was exceeded. Duration spent unloading containers was associated with higher levels of ethylene oxide, C2-alkylbenzenes and acetaldehyde. Exposed workers were more likely to report ≥10 symptoms, and particularly for the fatigue domain. Longer cumulative dura

Indians constitute the second-largest immigrant group in New Zealand. Asthma symptoms are often underestimated among Indian immigrants in New Zealand and other Western countries, resulting in increased morbidity and avoidable hospitalisations. Indian immigrant children's asthma has received little attention in the literature. Furthermore, research rarely includes children's voices, despite Article 12 of the United Nations Convention on the Rights of the Child, which guarantees their freedom of expression. The current study addresses these gaps by exploring the asthma experiences of Indian immigrant children and their family caregivers. The researcher adopted a constructivist grounded theory design, with social constructionism as its theoretical framework. Children (8–17 years of age) and their family carers were recruited through general practices, schools, and various Indian cultural associations in the Greater Wellington region. Intensive, semi-structured interviews were conducted with participants in a setting of their choice. The interviewing of children under 14 years of age was facilitated by drawing and photography. Concurrent data collection and analysis took place, accompanied by memoing. “Navigating asthma—The immigrant child in a tug-of-war” was the resultant grounded theory, in which the tug-of-war was the basic social process. Two types of tug-of-war were observed: one between the Indian and New Zealand cultures, and another between children’s and their family carers’ preferences. The three major categories in this theory, which corresponded to the three phases of the child's asthma journey, included being fearful, seeking support, and clashing cultures. These phases followed a cyclic pattern. During their asthma battle, participants often reflected on their own experiences and modified their plans as they learnt more from their own lives and social networks. This helped them cope with varying levels of fear in different situations. The theory explains

This thesis explores communication infrastructures at the margins of Indigeneity to understand Māori health and wellbeing meanings, challenges, strategies and solutions, articulated by whānau whose voices have been ignored, or not sought. Māori health and wellbeing understandings, forged amidst ongoing colonial processes of socioeconomic and health inequities, are best articulated by Māori with these lived experiences. The communication platforms established by the settler colonial state are infused with power dynamics that determine the communication rules including who can speak, what can be said and how that should be delivered. The privileging of communicative spaces to experts, leaders, and community champions, shaped by the underlying ideology of whiteness that organises the settler colonial state, forecloses the space to those not fitting these categories. Māori health and wellbeing meanings emphasise the totality of Whakapapa as a basis for communicating health and wellbeing. Kaupapa Māori theory, and Whakapapa as a super-connector of relationships both in the spiritual and physical domains, anchored the research. Rooted in Māori epistemology, the enduring intergenerational relationship between health and land formed the basis for the participants’ understandings of health and wellbeing. Positioned also in dialogue with the Culture-Centered Approach (CCA), we foreground whānau voices through the co-creation of voice infrastructures at the margins of Indigeneity, with whānau members candidly sharing lived experiences navigating health and wellbeing through the establishment of the Feilding advisory group. The interplay of land, rivers and health is a dominant theme. Strategies for improving health and wellbeing include co-creating communicative infrastructures, such as platforms for voices to emerge at the margins of Indigeneity. The campaigns documented buttress the importance of regaining stolen land, (re)connecting to land through the collective establishm