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Nutritional status, body composition and physical activity among older people living in residential care facilitiesCarlsson, Maine January 2011 (has links)
The main purpose of this thesis was to study, whether drinkable yoghurt enriched with probiotic bacteria could have any effect on constipation and body weight (BW) among older people with dementia. Further, it concerns poor nutritional status among older people with physical and cognitive impairments and its relationship with factors commonly occur in older people living in residential care facilities. It also discusses how body composition changes with ageing and the associations between changes in muscle mass and functional balance after a high-intensity weight-bearing exercise program (the HIFE program) and the ingestion of an additional milk-based protein-enriched energy supplement. A six-month feasibility study that included a probiotic drink was performed among 15 old people who were living in special units for people with dementia and who all had constipation. The effects of the probiotic drink on stool habits, and BW were studied. The outcome measures were followed daily for bowel movements and at three and six months for BW. The staff found the study easy to carry out and that the drink was well accepted by the participants. No convincing beneficial effects on stool habits were observed. In addition, a mean BW loss of 0.65 kg/month was registered. A poor nutritional intake, low physical activity level, and an over-night fast of almost 15 hours, 4 hours longer than recommended were also observed. As a part of the FOPANU Study (Frail Older People-Activity and Nutrition Study), a randomized controlled trial was carried out in Umeå - the associations between nutritional status and factors common among old people with physical and cognitive impairments living in residential care facilities was studied. Assessments were made of nutritional status using the Mini Nutritional Assessment (MNA) scale, fat-free mass (FFM) and fat mass (FM) using both bioelectrical impedance spectroscopy (BIS) and skinfold thickness measurements. The effects of a high- intensity functional exercise program with an additional protein-enriched milk drink on ability to build muscle mass were evaluated. Analyses were made to investigate whether nutritional status, assessed using the MNA scale, was associated with medical conditions, drugs, activities of daily living (Barthel ADL index), cognitive impairment (Mini Mental State Examination (MMSE)), and depressive symptoms (Geriatric Depression Scale (GDS)) at baseline. The associations were assessed with multiple linear regression analyses with additional interaction analyses. An independent association was found between poor nutritional status and having had a urinary tract infection (UTI) during the preceding year and being dependent in feeding for both women and men, and having lower MMSE scores for women. A large proportion of the participants, were at risk of malnutrition or were already malnourished. Women, but not men, had significantly lower Fat-Free Mass Index (FFMI) and Fat Mass Index (FMI) with age. Bioelectrical impedance spectroscopy results correlated with skinfold thickness measurements, but on different levels on value for FM%. Despite the high-intensity exercise had long-term effects (at six months, three months after the exercise) on functional balance, walking ability and leg strength. No effects on muscle mass and no additional effects from the protein-enriched drink could be observed after the three months of high intensity exercise. A negative, long-term effect on the amount of muscle mass and BW was revealed at six months (three months after the intervention had ended). The effects from the exercise did not differ for participants who were malnourished. No statistical interactions were observed between sex, depression, dementia disorder, and nutritional status, and the level of functional balance capacity on the outcome at three or six months. In summary, the majority of the included older people with dementia had a low dietary intake, low physical activity level, and lost BW despite receiving a probiotic drink supplement every day for six months. The supplementation had no detectable effect on constipation. Among the participants in the FOPANU Study, UTI during the preceding year was independently associated with poor nutritional status. Being dependent in feeding was associated with poor nutritional status as were lower MMSE scores for women but not for men. Despite the high-intensity exercise program had long-term effects on the fysical function was no effect on the amount of muscle mass at three months observed. The FFM and FM expressed as indexes of body height were inversely related to age for women, but not for men. A high-intensity exercise program did not have any effect on the amount of muscle mass. The ingestion of a protein-enriched drink immediately after exercise produced no additional effect on the outcome and the results did not differ for participants who were malnourished. The negative long-term effect on amount of muscle mass, and BW, indicate that it is necessary to compensate for increased energy demands during a high-intensity exercise program. High age, female sex, depression, mild to moderate dementia syndrome, malnutrition, and severe physical impairment do not seem to have a negative impact on the effect of a high-intensity functional weight-bearing exercise program. Consequently, people with these characteristics in residential care facilities should not be excluded from training and rehabilitation including nutrition. More research is needed in large randomized controlled trials to further explore the association between energy balance and malnutrition among frail old people, with a special focus on UTI and constipation, but also to study how physical exercise affects older people’s nutritional status. / Embargo
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Direct and correlated responses to selection for growth, feed efficiency and aspects of body composition in Japanese quail (Coturnix Coturnix Japonica)Sutedjo, H. Unknown Date (has links)
No description available.
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Mechanisms underlying glucocorticoid-induced protein wasting and potential treatment with anabolic hormonessBurt, Morton Garth, St Vincent's Clinical School, UNSW January 2007 (has links)
Protein wasting is a complication of glucocorticoid (GC) therapy. It causes substantial morbidity and there is no treatment. This thesis investigates the metabolic mechanisms underlying GC-induced protein wasting and the potential for anabolic hormones to reverse protein loss. The models of GC excess were Cushing's syndrome and GC therapy. Whole body protein metabolism was assessed using the leucine turnover technique and body composition by dual-energy X-ray absorptiometry to estimate lean body mass (LBM) and fat mass (FM). As previous studies demonstrated that LBM and FM influenced rates of protein metabolism, the magnitude of body compositional abnormality in Cushing's syndrome was determined. After accounting for the greater FM (30%) and lesser LBM (15%), protein metabolism in Cushing's syndrome was characterised by a significant increase in protein oxidation, an abnormality that leads to irreversible protein loss. Successful treatment of Cushing's syndrome normalised protein oxidation. Studies of the acute and chronic effects of therapeutic GCs revealed a time-dependent effect on protein metabolism. GCs acutely increased protein oxidation. However, the rate of protein oxidation during chronic therapy at a similar dose was not significantly different to untreated control subjects. This time-dependent change suggests that GC-induced stimulation of protein oxidation does not persist and could represent a metabolic adaptation to limit protein loss. This finding contrasts with that in Cushing's syndrome, where protein oxidation is persistently elevated. This difference may represent a dose effect. Studies in GH-deficient subjects revealed that GH induced a fall in protein oxidation that was significantly correlated with a subsequent gain in LBM. This suggests that the anabolic potential of a therapeutic substance can be predicted by its ability to suppress protein oxidation acutely. Finally, the potential for GH and androgens to reverse the metabolic effects of GCs was assessed. A preliminary study in GC users revealed that a GH dose of 0.8 mg/d was effective in reducing protein oxidation. In a subsequent study, the GH-induced reduction in protein oxidation in women on GCs was enhanced by combined treatment with dehydroepiandrosterone, an androgen. In summary, GCs induce protein loss by stimulating protein oxidation. GH reverses this effect and this action is enhanced by coadministration of androgens. GH and androgens may be used therapeutically to prevent protein loss induced by GCs.
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Direct and correlated responses to selection for growth, feed efficiency and aspects of body composition in Japanese quail (Coturnix Coturnix Japonica)Sutedjo, H. Unknown Date (has links)
No description available.
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Direct and correlated responses to selection for growth, feed efficiency and aspects of body composition in Japanese quail (Coturnix Coturnix Japonica)Sutedjo, H. Unknown Date (has links)
No description available.
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Physical activity and obesity in children: measurement, associations, and recommendationsDuncan, Scott January 2007 (has links)
Widespread increases in the prevalence of childhood obesity have raised the prospect of serious public health consequences in many countries. New Zealand is no exception; according to the most recent national estimates, approximately one in three children is overweight or obese. As a consequence, an understanding of the specific risk factors that predict this condition in children is becoming increasingly important. It is generally accepted that the promotion of physical activity is a key strategy for reducing the risk of childhood obesity. However, there is limited information describing physical activity and its relationship with body fatness in young New Zealanders. The overall aim of this thesis was to gain insight into the associations between excess fatness and physical activity in New Zealand children from a diverse range of socio-demographic groups. Three related studies were conducted to achieve this aim: a large descriptive survey of obesity and physical activity patterns in primary-aged children, and two preceding studies which develop the methodology for objective assessment of physical activity in this population. The first study provided the only validation data for the NL-2000 multiday memory (MDM) pedometer in children. In a sample of 85 participants aged 5-7 and 9-11 years, the NL-2000 offered similar accuracy and better precision than the widely used SW-200 pedometer (NL-2000: mean bias = -8.5 ± 13.3%; SW-200: mean bias = -8.6 ± 14.7%). The second study investigated reactivity to wearing pedometers over four 24-hour testing periods in 62 children aged 5-11 years. The sample was divided into two groups: one was given a full explanation of the function of the pedometer, while the other received no information prior to testing. The absence of significant differences in step counts between the first and last test periods indicated that there was no evidence of reactivity to this device for either preparation procedure. The central study presented in this thesis was the measurement of physical activity, body composition, and dietary patterns in 1,226 children aged 5-12 years, from which four chapters (4-7) were derived. The sample was ethnically diverse, with 46.8% European, 33.1% Polynesian, 15.9% Asian, and 4.1% from other ethnicities. Physical activity levels over three weekdays and two weekend days were assessed using NL 2000 pedometers. Percentage body fat (%BF) was determined using hand-to-foot bioelectrical impedance analysis with a prediction equation previously developed for New Zealand children. Waist and hip girths, height, and weight were measured using standard anthropometric techniques. Parent proxy questionnaires were used to assess demographic and lifestyle factors and pedometer compliance. The first reported analyses of this dataset (Chapter 4) examined the effect of weather conditions on children’s activity levels. In boys, a 10ºC rise in ambient temperature was associated with a 10.5% increase in weekday steps and a 26.4% increase in weekend steps. Equivalent temperature changes affected girls’ step counts on weekdays only (16.2% increase). Precipitation also had a substantial impact, with decreases in weekday and weekend step counts during moderate rainfall ranging from 8.3% to 16.3% across all sex, age, and socioeconomic (SES) groups. The aim of Chapter 5 was to understand the relationship between children’s step counts and their body mass index (BMI), waist circumference (WC), and %BF. Mean step counts for this sample were 16,133 ± 3,864 (boys) and 14,124 ± 3,286 (girls) on weekdays, and 12,702 ± 5,048 (boys) and 11,158 ± 4,309 (girls) on weekends. Significant associations were detected between steps.day-1 and both WC and %BF, but not between steps.day-1 and BMI. The findings in Chapter 6 extended these results by estimating the number of steps required to reduce the risk of excess adiposity in children (16,000 and 13,000 steps.day-1 for boys and girls, respectively). Finally, the study described in Chapter 7 examined the associations between excess adiposity and a series of demographic and lifestyle variables, providing the first assessment of body fat correlates in young New Zealanders. Our results indicated that children aged 11-12 years were 15.4 times more likely to be overfat (boys, %BF ≥ 25%; girls, %BF ≥ 30%) than those aged 5-6 years. In addition, the odds of overfat were 1.8 times greater in Asian children than in European children, and 2.7 times greater in the low SES group when compared with the high SES group. Three modifiable behaviours related to fat status were also identified: low physical activity, skipping breakfast, and insufficient sleep on weekdays. Clustering of these risk factors resulted in a cumulative increase in the prevalence of overfat.
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Women of childbearing age: dietary patterns and vitamin B12 statusXin, Liping January 2008 (has links)
From conception the dynamic balance between nutritional and activity factors play a role in the accumulation of risk for future disease. Maternal nutrient balance and the subsequent dietary pattern of the family set the path for the growth and development of the individual and therefore also for their offspring. There is strong evidence from studies in India that mothers who have a low vitamin B12 status, but high folate, will have children with higher adiposity and more cardiovascular risk factors than those with adequate B12. The B12 status is closely linked to the dietary pattern particularly the consumption of red meat which has a high B12 content. In New Zealand there are an increasing number of Indian migrants. Vegetarianism is also practiced by an increasing number including young women. In addition, there is a high rate (up to 60%) of unplanned pregnancies in New Zealand. In the 1997 New Zealand National Nutrition Survey (NNS97) report, vitamin B12 intake appeared adequate for the New Zealand population and breakfast cereals were reported as one major dietary source of B12. Cereals in New Zealand however, were not fortified with B12 and there was an error in the FOODfile™ data entries for B12 in some cereals. The raw data of reported B12 intakes in the 24-hour diet recall (24HDR) of NNS97 was reanalysed at the individual level by subtracting the B12 derived from breakfast cereals and applying the 2005 revised estimated average requirement (EAR) value. The possible prevalence of B12 insufficiency was 2.4 times that originally reported by the NNS97, translating into a prevalence of up to 27% of the population sampled. This analysis was limited as it was not adjusted for day-to-day variance or to the New Zealand population. This apparently high prevalence of risk for inadequate B12 intake in the surveyed individuals required confirmation that the B12 intake from 24HDR and also a 7-day diet diary (7DDD) was a valid assessment of B12 status. The group of particular interest is women of childbearing age (18-50y) with a range of eating patterns. Thirty eight women aged 19-48y; 12 non-red-meat-eaters (5 Indians vs. 7 non-Indians) and 26 red-meat-eaters (1 Indian vs. 25 non-Indians) participated in this validation study. Anthropometry and hand-to-foot bioelectrical impedance (BIA) were measured on the same day as a 24HDR was recorded. Fasting serum lipids, glucose, haematological parameters, and serum B12, holotranscobalamin II (holo-TC II, a specific B12 biomarker), and folate concentrations were measured. Foods eaten and time spent in physical activity during the following 7 days were extracted from 7DDD and 7-day physical activity diary (7DPAD). There was no significant correlation between dietary intake (24HDR or 7DDD) and biomarkers for B12 status. Indians reported lower mean daily B12 intakes in 7DDD than non-Indians (1.6 vs. 4.5 μg/day, p<0.001) and this was confirmed by Indians’ significantly low serum B12 (203 vs. 383 pmol/L, p=0.04) and holo-TC II (35 vs. 72 pmol/L, p=0.02) concentrations compared to non-Indians. A similar pattern was found between non-red-meat-eaters and red-meat-eaters in daily B12 intake in 7DDD (2.3 vs. 4.8 μg/day, p<0.001) and in B12 biomarkers (serum B12, 263 vs. 397 pmol/L, p=0.01; holo-TC II, 43 vs. 77 pmol/L, p<0.005). Non-red-meat-eaters reported significantly higher daily folate intake in 7DDD (359 vs. 260 μg/day, p=0.01) than red-meat-eaters but no significant difference was found in serum folate concentration between these groups (29 vs. 24 pmol/L, p=0.10). Indians/non-red-meat-eaters also reported lower daily protein intake and higher percentage of total energy from carbohydrate in 7DDD compared to non-Indians/red-meat-eaters but total reported energy intake tended to be under-reported and physical activity over-reported when assessed against estimated basal metabolic rate (BMR). Body composition varied by dietary pattern. Indians/non-red-meat-eaters had higher body fat percentage (BF %) and weaker grip strength than non-Indians/red-meat-eaters. In addition, Indians had a significantly higher waist-to-hip ratio (WHR) than non-Indians. Overall, the whole group reported that they were inactive. The median time spent in moderate, high and maximal intensity activities was only 19 minutes a day, which did not meet the NZ guideline for adults of 30 minutes a day. In this small study nutrient analysis of diet by 24HDR or 7DDD, was not a reliable or accurate way to assess B12 insufficiency. Questions about dietary patterns such as “do you eat red meat”, and taking ethnicity into account could more easily identify the at risk population. Supplementation and/or fortification of B12 should be considered before pregnancy.
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Modulation of avian metabolism by dietary fatty acidsNewman, Ronald Edward January 2000 (has links)
The role of dietary fatty acids and their subsequent effects on metabolism has received considerable attention in mammalian species. It is becoming increasingly clear that fatty acids have metabolic roles over and above their influence on energy density of the diet. Recent studies have linked changes in the fatty acyl composition of the plasma membrane, induced by the dietary fat profile, to alterations in both lipid and glucose metabolism. These dietary induced changes have profound effects on insulin action, glucose transport and enzyme activity that regulate triglyceride and fatty acid synthesis, factors that ultimately influence protein and lipid deposition of animals. Because of their high growth rate, broiler chickens have a high requirement for energy and the use of triglycerides as a major energy source has resulted in a fat carcass. A change in the glucose-insulin balance has been suggested as being the main reason for differences in adiposity between broilers selected for fatness or leanness. The hypotheses of this thesis is based on the finding that dietary polyunsaturated fatty acids (PUFA�s) increase the sensitivity of muscle tissue to insulin and this would presumably augment insulin-stimulated glucose uptake into muscle cells. Therefore, increasing the capacity of broiler muscle tissue to utilise glucose as its principal energy substrate would reduce the bird�s reliance on triglycerides and this inturn would result in a leaner carcass. The aims of this study are firstly to explore the role that dietary PUFA�s from the n-3 and n-6 series have on the growth and body composition of broiler chickens and secondly to determine the relationships between dietary fatty acid profile, tissue insulin sensitivity and lipid deposition. Because dietary fatty acids have been implicated in the modulation of hormones important for the growth and development of animals, a third aim of this thesis is to determine the effects of dietary n-3 and n-6 polyunsaturated fatty acids on pituitary and adrenal sensitivity. Since the modulation of metabolism by dietary fatty acids has been attributed to changes in the fatty acyl composition of the plasma membrane, the final aim of this study will be to investigate and characterise the molecular species of the breast muscle choline and ethanolamine phospholipids. Feeding either fish oil a source of n-3 PUFA�s or sunflower oil a source of n-6 PUFA�s fatty acids to broiler chickens resulted in a significant (P<0.01) reduction in the abdominal fat pad mass and a modest increase in breast muscle mass when compared to broilers fed edible tallow. Associated with the changes in carcass composition was an alteration in energy substrate utilisation. This was reflected by lower respiratory quotients and reduced triglyceride and insulin concentrations for the chickens fed the two PUFA diets. Coupled to the shift in energy metabolism was a significant (P<0.05) increase in the proportion of PUFA�s incorporated into the abdominal fat pad and breast muscle. The dietary fat supplements resulted in the incorporation of specific fatty acid subtypes. Feeding fish oil significantly increased the proportion of long-chain n-3 PUFA�s whereas feeding sunflower oil significantly increased the proportion of long-chain n-6 PUFA�s compared to tallow feeding whose tissues were dominated by a higher proportion of saturated fatty acids. It was further shown that dietary n-3 and n-6 PUFA�s enhanced glucose /insulin action. Feeding either fish oil or sunflower oil to broiler chickens increased insulin action when examined by an intravenous glucose tolerance test. The maximal insulin release in response to the glucose infusion was higher in the tallow fed group compared to either the sunflower oil or fish oil groups. To estimate the disappearance rate of glucose from the plasma and its incorporation into tissues, 2-deoxy-D-3H glucose was infused into each chicken. There were no significant differences in the clearance rate of 2-deoxy-D-3H glucose from the plasma. However, when measured under steady state conditions, the labelled glucose incorporation into the breast muscle was greater in birds fed fish oil compared to either tallow or sunflower oil feeding. The dietary fatty acid induced increase in insulin action suggests that the sensitivity of muscle cells to insulin was enhanced. This modulation of tissue sensitivity by dietary fatty acids was also shown to occur at the level of the pituitary. To provide an estimate of pituitary sensitivity, bolus GnRH and GHRH infusions were given on different days to chickens fed the three dietary treatments. Feeding sunflower oil (n-6 PUFA�s) increased the level of GH that was released in response to the GHRH infusion when compared to birds fed either tallow or fish oil (n-3 PUFA�s). This dietary fatty acid modulation appears to be specific to certain pituitary cell types as there was no effect on LH secretion following the GnRH infusion. Dietary fatty acid modulation of endocrine gland sensitivity is particular to the gland type. Although the dietary treatments mediated a distinct pattern in pituitary sensitivity to GHRH infusion, these same three diets did not influence adrenal sensitivity, as there was no difference in the corticosterone profile following either ACTH or CRF infusion. The previously observed physiological changes for the three dietary groups was expected to be positively correlated to an alteration of the plasma membrane phospholipids induced by the dietary fatty acids. Supplementation with fish oil (n-3 PUFA�s) significantly increased levels of both eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) into the choline (PC) and ethanolamine (PE) breast muscle phospholipids compared to either sunflower oil (n-6 PUFA�s) or tallow supplementation. The increase in n-3 PUFA incorporation was associated with a corresponding decrease in the proportion of arachidonic acid (AA; 20:4n-6) an event that would presumably alter substrate availability for the 1- and 2-series eicosanoids. However, feeding sunflower oil or tallow gave a molecular species profile that was remarkably similar in both fatty acid subtype and proportion. This suggests that the plasma membrane dynamics would be similar for these two dietary groups. Therefore, it is appears that factors other than a change in the fatty acyl- composition of the plasma membrane may be responsible for modifying the physiology of the broiler.
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The effect of four reduced-fat diets varying in glycaemic index, glycaemic load, carbohydrate and protein, on weight loss, body composition and cardiovascular disease risk factors.Price, Joanna McMillan January 2006 (has links)
Doctor of Philosophy (PhD) / Introduction: The conventional approach to weight loss, recommended by almost all health authorities around the world, has been to reduce the total amount of fat in the diet and replace with carbohydrates. However, research trials using this approach have produced only modest results at best, and despite the active promotion of low fat eating and an apparent decline in fat consumption, rates of overweight and obesity have continued to climb. More recently low glycaemic index (GI) and high protein diets have become popular and are widely used by the public. However, only a small number of randomised controlled trials have been conducted and none directly comparing the two. Both approaches effectively reduce glycaemic load (GL) and aim to reduce post-prandial glycaemia and insulinaemia. This study aimed to evaluate the ability of diets with reduced GL to enhance the weight loss effects of a reduced-fat diet, to compare the two approaches of reducing GL on metabolic and anthropometric changes, and to investigate any benefit of combining both approaches to produce the lowest GL. Methods: We conducted a 12-week intervention in 129 overweight or obese young adults who were assigned to one of four diets with varying GL, protein, carbohydrate and GI, but similar fat (30% energy), fat type and fibre content. DIET 1 (highest GL) contained 55% E as carbohydrate; DIET 2 was a low-GI version of DIET 1; DIET 3 was a high protein diet with 25% E as protein; DIET 4 (lowest GL) was a low-GI version of DIET 3. The increase in protein in DIETS 3 and 4 came primarily from lean red meat. All key foods and some pre-prepared frozen meals were provided to maximise dietary compliance. Outcome measures were body weight, body fat, lean mass, waist circumference and the following blood parameters: total cholesterol, LDL-cholesterol, HDL-cholesterol, triacylglycerols (TAG), free fatty acids, C-reactive protein, fasting insulin, fasting glucose and leptin. Insulin resistance and β-cell function were assessed using homeostatic model assessment (HOMA) and the newer computer models HOMA2-insulin sensitivity and HOMA2-β-cell function. Results: While all groups lost similar amounts of weight (4.2 to 6.2% of initial weight, p=0.09), the proportion who lost >5% of body weight varied significantly by diet: 31%, 56%, 66% and 33% in groups 1, 2, 3 and 4 respectively (p=0.011). Differences were strongest in women (76% of the total group) who showed significant differences among groups in percentage weight change (-3.7 ± 0.6%, -5.7 ± 0.6%, -6.5 ± 0.5%, -4.1 ± 0.7% respectively, p=0.005) and fat loss (-3.1 ± 0.4kg, -4.9 ± 0.6kg, -4.8 ± 0.4kg, -3.6 ± 0.7kg respectively, p=0.007). Total and LDL-cholesterol increased on DIET 3 (high protein) compared to a fall on diet 2 (high carbohydrate/low-GI, p=0.013). TAG, HDL-cholesterol and glucose homeostasis improved on all four diets, with no effect of diet composition. Goals for energy distribution were not achieved exactly: both carbohydrate groups ate less fat and the diet 2 group ate more fibre. Conclusions: Reducing GL, through either substituting low-GI foods or replacing some carbohydrate with protein, improved the efficacy of a reduced-fat diet in women and in those with high TAG. Combining both approaches to produce the lowest GL did not promote further weight or body fat loss. Although weight loss was similar in all four diets for the group as a whole, overall clinical outcomes were superior on the high carbohydrate, low-GI diet.
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Associations of patterns of daily life, physical fitness and body composition of primary school age childrenKira, Geoffrey Dean Juranovich January 2009 (has links)
The daily patterns of life, for example, food, physical activity and inactivity and sleep as well as physical fitness are associated with the accumulation of excess body fat in children. A positive energy balance between food (energy intake) and metabolism, particularly physical activity (energy output) is the accepted explanation. The reality of daily life for children is excessive calorie consumption, imbalances in macronutrient intake and missed opportunities for activity are being driven by the physical and social environment. Excess body fat tracks into adulthood and is associated with decreased insulin sensitivity, which may lead to increased risk of insulin resistance and chronic disease. Resting metabolic rate and substrate utilisation (measured by respiratory exchange ratio) are implicated in the prediction of weight gain in adults, but these relationships have been rarely explored in children. Both insulin and respiratory exchange provide insights into the pathways of accumulation of body fat. The purpose of this body of work presented here was to explore and explain how lifestyle patterns, substrate metabolism, physical fitness attributes and insulin resistance are related to excess body fat accumulation in children. “Project Energize” is a Waikato District Health Board-initiated through-school nutrition and physical activity intervention, operated in a growing number of primary schools throughout the Waikato. Data was collected from Project Energize control and programme schools between 2004 and 2006. The children that participated in this body of work were aged between 5 and 12 years of age (20% Māori). Fat mass (FM) change in Hamilton and Waikato primary school age children over a two year period is reported in study one (n=618). Study two (n=69) and three (n=169) are cross-sectional sub-studies of low decile schools (<3) that employ two methods of metabolic assessment; indirect calorimetry and glucose homeostasis; to investigate the relationships between food, activity, fitness with body composition and metabolic risk. More than 70% of the increase in body mass index (BMI) and percentage body fat (PBF) could be explained by the same measures two years earlier and more than 10% of the reported food, activity and sleep behaviours were able to be predicted from the responses two years earlier. There were no clear associations found with resting respiratory exchange ratio (RER), but resting metabolic rate (RMR) was best explained (45%) by fat free mass with a further 3% explained by cardiorespiratory fitness. Children with longer legs (as represented by height) travelled further, but FM attenuated final speed. Children with more fat had higher insulin resistance. Physical fitness was not associated with insulin resistance. Overall, a pattern of increased FM was linked to: 1. FM two years previously 2. a lesser speed attained in the 20m Shuttle Run Test and 3. higher insulin resistance. A focus on weight gain rather than change in FM and FFM, fitness and metabolic markers as the outcome of interventions is unlikely to show short or medium term changes. Therefore it is recommended that when instigating school-based nutrition and physical activity programmes, there must also be a focus on the daily patterns of life alongside community, family and culture-based partnerships to support sustainable behavioural change.
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