Massey Documents by Type
Permanent URI for this communityhttps://mro.massey.ac.nz/handle/10179/294
Browse
13 results
Search Results
Item Effect of green-lipped mussel (Perna canaliculus) supplementation on faecal microbiota, body composition and iron status markers in overweight and obese postmenopausal women: a randomised, double-blind, placebo-controlled trial.(Cambridge University Press, 2023-05-18) Abshirini M; Coad J; Wolber FM; von Hurst P; Miller MR; Tian HS; Kruger MCThe present study aimed to determine the effect of whole meat GSM powder on gut microbiota abundance, body composition and iron status markers in healthy overweight or obese postmenopausal women. This was a 3-months trial involving forty-nine healthy postmenopausal women with body mass index (BMI) between 25 and 35 kg/m2 who were randomly assigned to receive 3 g/d of either GSM powder (n 25) or placebo (n 24). The gut microbe abundance, serum iron status markers and body composition were measured at the baseline and the end of the study. The between-group comparison at the baseline showed a lower abundance of Bacteroides and Clostridium XIVa in the GSM group compared with the placebo (P = 0⋅04). At the baseline, the body fat (BF)% and gynoid fat% were higher in the GSM group compared with the placebo (P < 0⋅05). No significant changes were found in any of the outcome measures, except for ferritin levels that showed a significant reduction over time (time effect P = 0⋅01). Some trend was observed in bacteria including Bacteroides and Bifidobacterium which tended to increase in the GSM group while their abundance decreased or remained at their baseline level in the control group. Supplementation with GSM powder did not result in any significant changes in gut microbe abundance, body composition and iron markers compared with placebo. However, some commensal bacteria such as Bacteroides and Bifidobacteria tended to increase following supplementation with GSM powder. Overall, these findings can expand the knowledge surrounding the effects of whole GSM powder on these outcome measures in healthy postmenopausal women.Item Drivers of obesity : associations of physical activity, sedentary behaviour and diet on metabolic health and the gut microbiota : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Science at Massey University, Tāmaki Makaurau, Aotearoa New Zealand(Massey University, 2023) Slater, JoanneBackground: Regular physical activity (PA) and limited time spent sedentary are important for almost all aspects of health, including prevention and treatment of obesity. Aim: To describe the PA and sedentary behaviour (SB) of healthy, lean and obese, Pacific and NZE women, aged 18-45 years; and to explore the associations of PA and SB with diet, BF%, biomarkers of metabolic health, and gut microbiota composition. Methods: Pacific (n = 142) or NZE (n = 162) women aged 18–45 years with a self- reported body mass index of either 18.5–25.0 kg/m2 or ≥30.0 kg/m2 were recruited. Whole body dual-energy X-ray absorptiometry was used to subsequently stratify participants as either low (<35%) or high (≥35%) BF%. Eight-day accelerometery assessed PA and SB levels. Meeting the PA guidelines was defined as accumulation of ≥ 30 minutes of moderate or greater intensity activity on ≥ 5 days per week OR 150 minutes of moderate to vigorous PA (MVPA) per week. Dietary intake was assessed using a 5-day food record. Fasting blood was analysed for biomarkers of metabolic health, and whole body dual-energy X-ray absorptiometry was used to estimate body composition. Bulk DNA was extracted from faecal samples and the metagenomic sequences associated with the microbiota were analysed using MetaPhlAN and QIIME2 software. Adjusted multivariate regression models were conducted to explore the associations between PA, SB and diet, body composition and biomarkers of metabolic health, and between PA, SB and gut microbiota composition. Results: Less than half Pacific women were meeting the PA guidelines (high-BF%; 39% and low-BF%; 47%) versus 81% of low-BF% and 65% of high-BF% NZE women. Low-BF% Pacific women were more sedentary than all other women (p<0.05): Pacific low- 10.4 and high-BF% 9.93 and NZE low- 9.69 and high-BF% 9.96 hours/day. Every additional 10-minutes spent in MVPA was associated with 0.9% lower total and trunk fat and 0.7% lower gynoid fat in all women (p<0.05). Among Pacific women; every 100 cpm increase in total PA was associated with 6% lower fasting plasma insulin. Every 10-minute increase in MVPA was associated with 8% lower fasting plasma insulin in both ethnic groups (p<0.05). Among NZE women, every one-hour increase in sedentary time was associated with 0.8% higher gynoid fat (p<0.05), and longer weighted median sedentary bout length was associated with higher BF% (gynoid fat 0.3%, total body 0.4%, trunk 0.4%, android 0.4% and visceral fat 0.4% (p<0.05)) and 14% higher C-reactive protein (CRP) (p<0.05). No associations between SB and body composition or metabolic markers were found among Pacific women. There was no significant difference in average total energy intake between Pacific and NZE women or BF% groups. No women were consuming more than the carbohydrate AMDR (>65% total energy). Pacific women’s mean daily starch intake was significantly higher than NZE women (g/day, and % total energy intake). Only the NZE low-BF% groups mean fibre intake was above the recommended daily intake of ≥25g/day. All the women that were in the lowest quartile of fibre intake, and particularly the NZE women, had a lower odds of meeting the PA guidelines (OR 0.72 (p=0.008) and OR 0.66 (p=0.021) respectively) compared to women in the top three quartiles of fibre intake. All the women that were in the lowest quartile of polyunsaturated fat intake, especially Pacific women had a lower odds of meeting the PA guidelines compared women in the top three quartiles (0.76, p=0.027 and OR 0.67, p=0.030 respectively). Among NZE women, every one SD increase in total PA (197 cpm/day) was associated with 36.3% higher relative abundance of Erysipelotrichaceae (p=0.031) and 37.9% lower relative abundance of Verrucomicrobiaceae (p=0.029). Every one SD increase in SB (1.45 hours/day) was associated with a 28% lower relative abundance of Erysipelotrichaceae (p=0.030). Every one SD increase in NZE women’s total PA was associated with 23.1% higher Firmicutes:Bacteroidetes ratio (p=0.031), whereas among Pacific women, every 1 SD increase in MVPA was associated with 22.8% lower (p=0.034) Firmicutes:Bacteroidetes ratio. Conclusion: Increased time spent in PA of all intensities and breaking-up prolonged SB was associated with healthier body composition and lower metabolic disease risk in Pacific and NZE women. Compared to NZE, the impact of increased total PA on fasting insulin may be greater in Pacific women and inflammation may be a pathway through which SB impacts cardiovascular risk, especially for NZE women. Although higher total PA and lower SB was associated with some aspects of the gut microbiota composition, more needs to be known about the mechanisms driving associations between PA SB and the gut microbiota to enable these findings to be interpreted.Item Muscle strength and muscle mass in older adults : a focus on protein intake, distribution, and sources : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Science at Massey University, Albany, New Zealand(Massey University, 2023) Hiol, Anne NadineBackground: 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) per day, meal, and source were calculated by dividing the absolute protein intake (g) by each participant's body weight (kg). Statistical analyses: A linear regression analysis was performed to determine the association between muscle mass and muscle strength. This analysis was conducted on males and females based on obesity classifications using body fat percentage (obesity ≥ 30% males, ≥ 40% females). The relative protein intake was compared against a cut-off value of 1.2 g of protein per kg body weight (g/kg BW) per day. The distribution of protein across the three meals was expressed as the coefficient of variance (CV), the average of total protein intake per main meal and the number of meals exceeding 0.4 g/kg BW of protein across the day. Sources of protein intake were assessed at breakfast, mid-day and the evening meals. Results are presented as a percentage of the total protein intake for each meal. Finally, linear regression analyses were conducted separately in males and females to investigate the relationships between BMI- muscle strength and protein intake, distribution and sources, accounting for relevant confounders. Results: Muscle mass was a significant predictor of muscle strength in non-obese participants. However, in participants with obesity, muscle mass was no longer a significant predictor of muscle strength. More than half of the participants had a protein intake of < 1.2 g/kg BW per day (62% females, 57% males). Protein intake was unevenly distributed throughout the day (CV = 0.48 for males and females) and was inadequate for reaching 0.4 g/kg BW at breakfast (for both males and females) and at the mid-day meal for males. The main sources of protein at breakfast were milk (28%), breakfast cereals (22%), and bread (12%); at the mid-day meal, bread (18%), cheese (10%) and milk (9%); and at the evening meal, meat provided over half the protein (56%). In females, relative protein intake was positively associated with muscle strength adjusted BMI (BMI-muscle strength) (r2 = 0.15, ρ < 0.01). Protein derived from either dairy and egg (ρ = 0.03); and plant sources (ρ < 0.01) was related to BMI-muscle strength but not protein from meat and fish (ρ = 0.55). Greater frequency of protein consumption of at least 0.4 g/kg BW per meal was associated with BMI-muscle strength (ρ = 0.01), but the coefficient of variance for protein intake distribution was not related to BMI-muscle strength (ρ = 0.47). There was no relationship between BMI-muscle strength and total daily protein intake, protein from meat and fish; dairy and egg; and plant-based sources, or distribution defined as frequency of protein consumption of at least 0.4 g/kg BW per meal or CV in male older adults. Conclusions: Obesity should be considered when measuring associations between muscle mass and muscle strength in older adults. A higher BMI-adjusted muscle strength was associated with consuming more protein each day and a higher frequency of consumption of a meal containing at least 0.4 g/kg BW; and from dairy and egg; and plant food sources in female older adults. There was no correlation between protein intake, distribution and sources and muscle strength in males. Protein intake was less than 1.2 g/kg BW per day and 0.4 g/kg BW per meal for a large proportion of older adults. At breakfast and the mid-day meals the main sources of protein were from cereals and dairy products, and from meat sources at the evening meal. Further research is needed to investigate how best to optimise protein intake to increase and maintain muscle mass and muscle strength in older adults from the general population.Item The link between dietary diversity and body composition in New Zealand European, Māori and Pacific women : the women's EXPLORE study : a thesis presented in partial fulfilment of the requirements for the degree Master of Science in Nutrition and Dietetics, Massey University, Albany, New Zealand(Massey university, 2019) Bell, Catherine AnneEating a diverse diet improves diet quality and nutritional adequacy, but may be higher in energy and discretionary foods, which are associated with obesity. We aimed to utilise a newly validated dietary diversity questionnaire (DDQ) to explore the dietary diversity and food variety of New Zealand European, Māori and Pacific women and how dietary diversity and food variety may link to different body composition profiles (BCPs). Women’s (n=235) waist circumference, body mass index and body fat percentage (BF%) was used to categorise them into one of three BCP groups (normal-fat, hidden-fat, apparent- fat). Dietary intake was assessed using a Food Frequency Questionnaire (energy and nutrients), alongside a validated DDQ, which assessed participants dietary diversity and food variety scores (DDS and FVS). Dietary diversity was high (88%, 22/25) whilst food variety was comparatively low (31%, 78/237), especially within carbohydrates, fruits, vegetables and seafood. Overall, DDS and nutritious-DDS was lower for Pacific participants (P<0.005), whilst discretionary-FVS was higher for Māori and Pacific participants (both P<0.001). Regarding obesity, nutritious-DDS was higher in participants with a non-obese BMI (P=0.024) and BF% (P=0.029), compared to obese participants. Both DDS and N-DDS negatively correlated to WC and BF% (P<0.005). Participants in the highest tertile of DDS and nutritious-DDS had a lower WC (P=0.015, P<0.001), BMI (P=0.048, P=0.004), and BF% (P=0.002, P=0.011), despite consuming more energy (P=0.016). We were unable to demonstrate any significant anthropometric differences between tertiles of discretionary DDS nor discretionary FVS. Our results support previous prospective studies, showing that consuming an increased variety of nutritious foods may be associated with reduced female obesity, possibly more so than omitting discretionary foods. Health promotion should encourage exchanging rather than excluding, discretionary foods.Item Iron deficiency and risk factors in pre-menopausal females living in Auckland, New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Nutrition and Dietetics, Massey University, Albany, New Zealand(Massey University, 2019) Lim, KimberleyBackground: Iron Deficiency (ID) is the most common nutrient deficiency worldwide, affecting one third of the world’s population. In New Zealand (NZ), the highest rates are found within pre-menopausal females, with previously identified risk factors for ID including low meat intake, heavy menstruation and blood donation. Emerging risk factors such as inflammation and obesity are yet to be explored in NZ, along with the master hormone of iron regulation, hepcidin. Objectives: To describe iron and hepcidin status within premenopausal females, and identify risk factors for ID. Methods: Females (n=170) aged 18–45 were recruited. Biomarkers of iron status were measured: Serum ferritin (Sf), haemoglobin, soluble transferrin receptor, hepcidin as well as inflammatory markers C-reactive protein and interluekin-6. Body composition was measured using bioelectrical impedance analysis, and lifestyle factors were assessed using questionnaires, including a previously validated food frequency questionnaire. Variables known to potentially influence iron status were entered into multiple linear regression analysis to identify predictors of Sf. Results: Iron deficiency was confirmed in 55.8% of participants (Sf < 30µg·L-1). Prevalence of ID did not differ significantly (p=0.141) between South Asians (64.3%), NZ Europeans (51.6%), and those of other ethnicities (45.5%). Hepcidin concentrations were higher in those who were iron sufficient (Sf ≥ 30µg·L-1) (6.62nM vs 1.17nM, p<0.001). South Asian females had higher hepcidin (8.78nM) concentrations, compared to NZ Europeans (6.28nM) and those of other ethnicities (4.89nM) (p=0.026). The higher hepcidin concentrations in South Asian participants are possibly associated with these participants having a higher BMI (p<0.001), body fat percentage (p<0.001) and interlukein-6 (p<0.001) than NZ Europeans and other ethnicities. Hepcidin (β=0.082, p<0.001) and frequency of meat intake (β=0.058, p=0.001) were identified as significant predictors of Sf in NZ Europeans. Hepcidin was the only identified predictor of Sf in South Asians (β=0.138, p<0.001) and those of other ethnicities (β=0.117, p<0.002). Conclusion: The study confirms a positive relationship between hepcidin and Sf in NZ females, highlighting hepcidin’s potential as an emerging biomarker to identify ID. Furthermore, there were differences in hepcidin levels between ethnicities, which may be linked to higher levels of body fat and inflammation.Item Investigating the relationships between body fat distribution, metabolic biomarkers and endocrine regulators in Pacific and New Zealand European women : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Nutrition and Dietetics, Massey University, Albany, New Zealand(Massey University, 2019) Mickleson, Laura JaneBackground: The burden of overweight and obesity continues to rise throughout the world, including New Zealand (NZ). Obesity prevalence differs among ethnic groups in NZ and this is associated with considerable health inequities. For example, Pacific peoples living in NZ have higher rates of obesity‐related health issues, compared to NZ Europeans. Understanding the link between body composition and metabolic health is essential for the development of more effective preventative and intervention strategies for different population groups, who may have different metabolic disease risk profiles. Aims: This research aims firstly, to investigate metabolic biomarkers and endocrine regulators in two distinct groups of women with different body fat profiles (normal and obese) and of high metabolic disease risk (Pacific women) or moderate metabolic disease risk (NZ European women); and secondly, to compare different approaches of assessing body composition and fat distribution and their relationship with metabolic and endocrine profiles. Design: A cross‐sectional study conducted in 304 Pacific and NZ European women aged 18‐45 years. Anthropometry, a range of body composition and fat distribution measurement approaches, metabolic biomarkers (including lipids, markers of glucose metabolism and inflammation markers) and endocrine regulators (insulin and leptin) will be investigated. Outcomes: Total body fat percentage (BF%) measured by bioelectrical impedance analysis (BIA) correlated strongly with BF% measured by dual X‐ray absorptiometry (DXA). Waist‐to‐hip ratio (WHR) had weak associations with android fat percentage and BF% measured by DXA, whereas waist circumference (WC) and waist‐to‐height ratio (WHtR) performed better in this respect. Anthropometric measurements had similar correlations with total body fat percentage and regional fat depots for both ethnic groups. For each ethnicity, women in the high body mass index (BMI) group had higher circulating concentrations of fasting insulin, fasting glucose, glycosylated haemoglobin (HbA1c), triglycerides and total cholesterol to high‐density lipoprotein (TC/HDL) ratios, and lower circulating HDL cholesterol concentrations in comparison with the normal BMI group. Gynoid fat percentage had weak associations with circulating cardio‐metabolic risk factors, including low‐density lipoprotein cholesterol (LDL‐C), triglycerides, HbA1c, fasting insulin and fasting glucose concentrations. On the other hand, android and visceral fat percentages had stronger, positive associations with these cardio‐metabolic risk factors. Furthermore, BF% measured by DXA and BMI explained a similar amount (57.1% and 49.7% respectively) of the variance in leptin concentrations. Conclusion: Our findings suggest that in a New Zealand population with markedly different body fat profiles, assessment of WC, WHtR and BMI are effective tools for assessing adiposity and the associated cardio‐metabolic disease risk factors in a clinical setting, whereas WHR does not appear to be a useful tool. This thesis research provides strong evidence that these clinically important and effective tools should continue to be used in dietetic practice, across different population groups with different metabolic disease risks and different body fat profiles.Item New pathways to obesity prevention and metabolic health : the relationship between diet and the gut microbiome : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Science at Massey University, Tāmaki Makaurau, Aotearoa New Zealand(Massey University, 2020) Renall, NikkiBackground Diet is one of the key drivers of the global obesity epidemic. Based on the results of rodent experiments, the gut microbiota may play an important role in this multifaceted disease. Additionally, the microbiota is known to be influenced by the habitual diets consumed by humans. Aims and objectives The aim of this PhD research was to characterise the habitual dietary intake of two New Zealand populations (Pacific and New Zealand European (NZE) women) with different metabolic disease risk and body fat profiles (lean and obese). The first objective of the research was to explore the relationship between habitual macronutrient intake in relation to body fat content and metabolic health markers. The second objective was to characterise a posteriori dietary patterns (derived from multiple days of dietary assessment) and to explore the association with body fat content and metabolic health markers. The third objective was to explore the characteristics of microbiota composition in relation to habitual diet (dietary patterns, foods, and nutrients), body fat content and metabolic health markers. Methods Between July 2016 and September 2017, Pacific (n=126) and NZE (n=161) women, aged 18-45 years, living in Auckland, New Zealand, were recruited to a cross-sectional study, based on their body mass index (lean and obese) and stratified as having low (<35 % body fat) or high (≥35 % body fat) body fat percentage (BF%). Dietary intake was assessed using a 5-day estimated, non-consecutive, food record and a validated semi-quantitative food frequency questionnaire, which were used to calculate habitual dietary intake using the National Cancer Institute (NCI) method. Body composition and BF% were assessed by dual-energy x-ray absorptiometry. Fasting blood samples were analysed for metabolic biomarkers (lipid and glucose profiles). Bulk DNA was extracted from faecal samples and the metagenomic sequences associated with the microbiota were analysed using MetaPhlAN and QIIME2 software. Enterotypes characterising the microbiotas of the participants were predicted in R and the species that defined enterotypes were determined using STAMP software. A posteriori dietary patterns were identified using principal component analysis. Adjusted multivariate regression models were conducted to explore the association between BF% and habitual macronutrient intake and adherence to dietary patterns, as well as the association between microbiota composition and habitual diet. Results There were no significant differences in BF% between Pacific and NZE women (p=0.498). Higher energy adjusted habitual dietary fibre (DF) intake was associated with lower BF% (β= -0.35, p≤ 0.001) for both Pacific and NZE women, and this relationship became stronger after further adjustments for protein (g/day), total carbohydrate (g/day), and total fat (g/day) intake (β= -0.47, p≤ 0.001). Women in the highest tertile of DF intake were older, had lower concentrations of fasting plasma insulin, and lower socioeconomic deprivation levels. Four dietary patterns that explained 30.9 % of the observed variance in habitual diet were identified. Higher adherence to dietary patterns characterised by core foods (the “colourful vegetable, plant protein, and dairy” and “fruit, starchy vegetables, and nuts” patterns) were inversely associated with BF%. In contrast, patterns characterised by more ‘discretionary’ foods (“sweet and fat rich carbohydrate”) and less diversity of core foods (“animal meat and fat”) were positively associated with BF% for both Pacific and NZE women. Three enterotypes were identified by higher relative abundance of specific bacterial species: enterotype 1 was characterised by Pacific and NZE women (n=146) and the abundances of Faecalibacterium prausnitzii and Eubacterium rectale. Enterotype 2 (n=70) was characterised by Pacific women, Bifidobacterium adolescentis, Bifidobacterium bifidum, and Lactobacillus ruminis; and by higher BF%, visceral adipose tissue, and concentrations of fasting insulin. Enterotype 3 (n=70) was predominately found in older NZE women with lower deprivation, and characterised by Akkermansia muciniphila, Ruminococcus bromii, Subdoligranulum species, and Methanobrevibacter smithii. Adherence to the “colourful vegetables, plant protein, and dairy” dietary pattern was positively associated with enterotypes 1 and 3 and negatively with enterotype 2. Conclusion Consuming more core foods rich in dietary fibre was associated with enterotypes 1 and 3, including lower adiposity and metabolic disease risks. In contrast, consuming more discretionary foods was associated with enterotype 2, higher adiposity and metabolic disease risks. This PhD research highlights habitual diet-microbiota-host associations, which are similar for a population of women with different metabolic disease risk, body fat profiles, and deprivation levels. Whether the microbiota is a cause or consequence of metabolic health has yet to be elucidated. However, habitually consuming more core foods rich in dietary fibre is associated with microbiota composition, and lower metabolic disease risks.Item Investigating eating behaviours as predictors of body composition and dietary intake in New Zealand European, Māori and Pacific women - the women's EXPLORE study : a thesis presented in partial fulfilment of the requirements for the degree Master of Science in Nutrition and Dietetics, Massey University, Albany, New Zealand(Massey University, 2018) Shepherd, Katrina JadeBackground/Aim: Internationally, eating behaviour has been linked with an optimal and adverse body composition in women. However no study to date has examined eating behaviour in female New Zealand ethnic groups. Therefore, the aim of this study was to investigate eating behaviours as predictors of different body composition factors and dietary intake in New Zealand European (NZE), Māori and Pacific women, aged 16-45 years, participating in the women’s EXPLORE study. Methods: Women (N=368) were assessed for basic anthropometry, total adiposity, regional adipose distribution and lean mass using height, weight, circumferences, dual x-ray absorptiometry and air-displacement plethysmography. Body composition profiles (normal-fat, hidden-fat and apparent-fat) were established using parameters of body mass indices and body fat percentages. The validated Three-Factor Eating Questionnaire (TFEQ) and New Zealand Women’s Food Frequency Questionnaire were both used to examine eating behaviour and dietary intake, respectively. The TFEQ examined Restraint (Flexible and Rigid), Disinhibition (Habitual, Emotional and Situational) and Hunger (Internal and External). Combinations of behaviour (sub-groups) were established from the main categories and also examined. Results: Restraint was significantly higher in NZE than Pacific women (p = 0.015). Disinhibition was significantly higher in the apparent-fat profile than normal-fat profile (p < 0.001). Likewise, Hunger was significantly higher in Pacific (p < 0.001) and the apparent-fat profile (p = 0.034) than NZE women and women with normal-fat profile, respectively. Adverse tendencies of Habitual Disinhibition, and External Hunger were more prominent in Pacific and the apparent-fat profile than NZE women and normal-fat profile, respectively (all p < 0.05). External Hunger was more prominent in the hidden-fat profile than normal-fat profile (p = 0.001). When accounting for age and ethnicity the most significant predictors of BMI and BF % were Restraint (p = 0.007 and p = 0.005 respectively), Disinhibition (both p < 0.001), Habitual Disinhibition (both p < 0.001) and Emotional Disinhibition (both p < 0.001). Non-ideal behaviour combinations (Low Restraint High Disinhibition and High Hunger High Disinhibition) generally corresponded to significantly higher body composition markers and dietary intake (p < 0.05). Pacific women were three times more likely to have High Hunger High Disinhibition than NZE women (p = 0.004). Low Restraint High Disinhibition and High Hunger High Disinhibition increased by 12% and 11%, respectively from the normal-fat profile to hidden-fat profile (both p < 0.001). Conclusions: The TFEQ eating behaviour categories, sub-categories and sub-groups can significantly vary between ethnicities and body composition groups. Tailored interventions to promote Restraint (particularly Flexible Restraint) and counteract Disinhibition (particularly Habitual Disinhibition and Emotional Disinhibition), Hunger (particularly External Hunger), Low Restraint High Disinhibition and High Hunger High Disinhibition could enhance eating behaviour and dietary intake and help optimise weight management in young New Zealand women.Item Exploring physical activity profiles of Māori, Pacific and European women from Aotearoa New Zealand : implications for body composition and metabolic health : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Sciences at Massey University, Auckland, New Zealand(Massey University, 2018) O'Brien, Wendy JeanBackground: Regular physical activity provides extensive health benefits, and is a key modifiable risk factor for chronic disease. Aims and objectives: The research aim was to robustly explore the physical activity profiles of Māori, Pacific and European women aged 16-45 years, living in New Zealand, to understand ethnic differences in their physical activity profiles and its consequences on body composition and metabolic health markers. Objectives were to: investigate the challenges of collecting hip-worn accelerometer data; determine ethnic differences in physical activity levels, and associated disease risk of being overweight-obese; investigate whether substituting sedentary behaviour with equal time in physical activity can predict improved health markers; examine recreational physical activity preferences to make ethnic-specific suggestions for meeting physical activity guidelines. Methods: Participants were 406 healthy premenopausal Māori, Pacific and European women aged 16-45 years, stratified by body composition profile and ethnicity. Physical activity data were collected using hip-worn accelerometers and Recent Physical Activity Questionnaire. Body composition was assessed using anthropometry, air displacement plethysmography and dual-energy x-ray absorptiometry. Metabolic biomarkers were measured from venous blood samples. Results: Accelerometer wear compliance was 86%, but discomfort (67%) and embarrassment (45%) hindered wear. European women (92.7%) returned more valid data than Māori (82.1%) or Pacific (73.0%, p < 0.04) women. More overweight-obese European (67%) than Māori (49%) or Pacific (32%, p < 0.001) women achieved physical activity guidelines. Achieving guidelines was strongly associated for Māori, inversely with total and regional fat percentages and clustered cardiometabolic risk score (p < 0.01) and positively with body lean percentage (p = 0.21), and for European women inversely with regional fat percentages and positively with body lean percentage (p ≤ 0.036). Substituting sedentary time with moderate-vigorous physical activity predicted improvements (p < 0.05) in total (14.8%) and android (12.5%) fat percentages, BMI (15.3%) and insulin (42.2%) for overweight-obese Māori women, and waist-to-hip ratio (6.4%) among Pacific women. Recreational physical activity preferences varied by ethnicity, possibly due to cultural/ethnic factors. Suggestions to increase physical activity were: family/whanaubased team activities for Māori women; community/church-linked games and fitness sessions for Pacific women; adding variety to existing activities for European women. Conclusions: Ethnicity played a major role in: collecting data; amounts/types of physical activity performed; implications of physical activity on health markers. Tailoring physical activity recommendations for specific ethnic groups could have major positive health implications for New Zealand women.Item Body-composition assessment using air displacement plethysmography in healthy term infants : an observational study : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Science in Nutrition and Dietetics at Massey University, Albany, New Zealand(Massey University, 2016) Ichhpuniani, BaniBackground: Infant body weight and composition at birth have been recognised to be important indicators of fetal growth, maternal and offspring health, and later health outcomes. While it is well documented that average birth weight varies significantly between New Zealand-born infants of different ethnicities, there is limited evidence on body composition in new-born infants. Ethnic differences in body composition have been reported in New Zealand adults and children and it is currently unknown whether these differences are evident shortly after birth. The aim of this study was to examine the differences in fat mass (FM) and fat free mass (FFM) using Air Displacement Plethysmography (ADP) between NZ European (reference group), Māori, Pacific, Asian and South Asian healthy term infants. Method: Healthy term infants (37 to 42 weeks’ gestation) were recruited from Auckland City Hospital (ACH). Birth parameters were recorded and weight, length, and head circumference and waist circumference were measured using standardised techniques. Air Displacement Plethysmography (ADP) was used to measure fat mass (FM) and fat free mass (FFM) of the infants. Ethnicity of all infants and their mothers was classified using standard ethnicity data protocols. Dummy variable multiple linear regression analysis and t-tests were used to compare FM and FFM of Māori, Pacific, Asian, and South Asian infants with New Zealand European (NZE) infants. Results: Body composition was assessed in 214 healthy term infants at a mean age of 1.7±0.85 days, while adjusting for gender and postnatal age. South Asian infants had significantly lower FFM (2691.7±389.7g vs 2938.6±364.0g, P= 0.006) and weight than NZE infants (3045.5±535.2g vs 3352.3±575.8g, P= 0.014). They also had the smallest head (34.2±1.7cm vs 35.4±1.7cm, P= 0.002) and waist circumference (31.5±3.0cm vs 33.2±2.1cm, P= 0.003). Waist circumference of Asian infants was also significantly smaller than NZ European infants (32.3±2.1cm vs 33.2±2.1cm, P= 0.044). When categorised by gender, males had significantly greater FFM, weight, length and head circumference (P< 0.05). No gender or ethnic difference was noted in FM (g) or %FM. Conclusion: This is the first study in New Zealand to report body composition in healthy term infants using ADP. While no differences in FM were seen between NZE and each of the other ethnicities, the differences noted in FFM and weight between NZE and South Asian infants were comparable to other studies. Longitudinal assessment of changes in FM and FFM is needed to establish the significance of ethnic differences.