Thesis (MNutr)--University of Stellenbosch, 2008. / Bibliography. Also available via the Internet.

Title: The relationship of BMI and body composition parametres in UK FTVS students Objectives: The main goal of this diploma thesis is to evaluate the relationship between BMI and some selected parameters of body composition assessed using a bioelectric impedance device (BIA - Tanita MC - 980). Methods: The diploma thesis has the character of an empirical research (observation method). The bioelectric impedance method (BIA - Tanita - MC - 980) was used to analyze the body composition. The relationships between BMI values and individual body composition parameters were evaluated using the Spearman's correlation coefficient. The statistical significance level was set at α = 0,05. In total, 170 students were studied (85 physiotherapy students, 85 physical education students). The group was further subdivided into several specific subgroup by gender, field of study and physical activity. Results: The results revealed a series of finding within the sample group including the following: an insignificant correlation (rs = 0,062) between BMI and body fat (%), a significant correlation (rs = 0,386) between BMI and fat mass (kg), a significant correlation (rs = 0,603) between BMI and visceral fat, a significant correlation (rs = 0,624) between BMI and fat-free mass (kg), a significant correlation (rs =...

Regular consumption of dairy is thought to aid in preserving lean body mass while decreasing body fat, however, studies have reported inconsistent results. The overall aim of this cross-sectional study was to examine the influence of dairy consumption on body composition, specifically body fat percentage, among college-aged individuals in Mississippi. Total dairy consumption, type of dairy, and the relationship between race and sex were examined in 580 participants aged 18-26 years. Two-tailed correlation tests revealed a nonsignificant relationship between frequency of dairy consumption and body fat percentage among males, (r = .02, p = .68, n = 98) and females, (r = .06, p = .17, n = 469). There was also a nonsignificant interaction among race categories and dairy consumption. Future studies examining college-aged individuals should be performed with a more diverse sample to see if a relationship exists.

Energy cost of walking at any given speed is higher for heavier people than for lighter ones. We compared adolescents that were matched for total body mass but had different body composition. Nine pairs of boys (16.37 ± 1.57 years in the lean group and 12.90 ± 1.49 years in the obese group) participated. Metabolic energy expenditure (EE) was compared at three walking speeds and moments and powers at the hip and ankle at push off were analyzed. Assessment of fat mass and distribution was performed using whole body dualenergy x-ray absorptiometry. A repeated measure ANOVA was performed when matched pairs were compared. Based on multiple regression, pooling all subjects together, body mass was the main predictor of EE. Variance explained by adiposity increased with increasing speed. Obese subjects tended to expend more energy than their lean pairs at the two fastest walking speeds (5 and 6kph). There was a significant difference between the pairs in EE (kJ/min) at 6kph (p<0.05). Ventilation showed the same pattern as V02net (exercise V02 minus resting V02), increasing with increasing speed and showing differences between the pairs at the fastest speed. Heart rate was consistently higher in the obese subjects. Stride length, stride rate, progression velocity and moments and powers at the hip and ankle at push off were not correlated with body fat. No relationship between V02net. total amount of body fat, or segment fat content was found. Total amount of fat in the body and the amount of fat in the legs had no influence on gait parameters. In conclusion, excess body fat does not influence the energy cost of walking at low speeds but does so at 6kph. Obese subjects demonstrated higher effort at all speeds. Amount of fat distributed in body segments does not influence either energy cost of walking or mechanical gait parameters. / Thesis / Master of Science (MSc)

Call number: LD2668 .T4 1978 N33 / Master of Science

Globally, overweight and obesity in childhood has already reached pandemic proportions, and this condition is associated with various health problems such as, insulin-resistance, Type 2 diabetes mellitus, and cardiovascular problems, such as hypertension, ischaemic heart disease, and stroke. Overweight and obesity are increasing in most countries, especially developing countries where the rates of obesity have tripled in those that have adapted a Western lifestyle. In low- and middle-income populations, particularly in urban areas, overweight and obesity in children is on the increase. Thus body composition profiles are used to determine the risk category of children such as underweight, normal, overweight, and obese. Overweight and obesity have a negative impact on both the physical and psychological levels of wellbeing during childhood and adolescence. Research on African and South African children living in rural areas on the body composition and prevalence rates will provide an opportunity to understand the role of development in children and adolescents and the importance thereof. The purpose of this study was to determine the status of body composition and the effect of gender, age, and race on body composition. This dissertation comprises four chapters, of which one chapter can be read independently as it is written in the form of a research article. MAIN FINDINGS A literature review was conducted to gain more insight regarding body composition status of children throughout the world, and in Africa and South Africa, and the role that body composition plays in children and adolescents. The importance of these aspects is highlighted and discussed in Chapter Two. Cross-sectional data on a total of 280 learners (109 boys and 171 girls) aged 14 years, who are part of the Physical Activity Longitudinal Study from the Tlokwe municipality area, are participants in the study. Body mass, stature, and skinfolds were used to determine body composition and body mass index of the participants. All data was analysed using SPSS Version 21.0 (SPSS Inc., 2012). The statistical level was set at p-value ≤ 0.05. The results of this study indicate that out of 280 learners 13.1% are overweight, 29.1% normal weight and 57.8% underweight. Boys had a lower overweight value when compared to the girls (9.1% vs 15.7%). In addition, the results show that African girls had a higher prevalence for overweight (15.8% vs 15.4%) than their Caucasian counterparts. As for the impact of gender, age and race-independent effects on body composition or BMI, the results also show no significant (p ≥ 0.05) age-independent effect on body composition measures of percentage body fat, sum of six skinfolds, fat free mass and waist-to-height ratio. In conclusion, overweight and obesity is a growing problem among children and adolescents, especially African girls and Caucasian girls in the Tlokwe municipality. Furthermore, recommendations are made about the implementation of school-screening programmes in semi-urban areas. The role of the government, parents, and teachers, and the importance of health professionals must also be considered. / MSc (Biokinetics), North-West University, Potchefstroom Campus, 2015

Globally, overweight and obesity in childhood has already reached pandemic proportions, and this condition is associated with various health problems such as, insulin-resistance, Type 2 diabetes mellitus, and cardiovascular problems, such as hypertension, ischaemic heart disease, and stroke. Overweight and obesity are increasing in most countries, especially developing countries where the rates of obesity have tripled in those that have adapted a Western lifestyle. In low- and middle-income populations, particularly in urban areas, overweight and obesity in children is on the increase. Thus body composition profiles are used to determine the risk category of children such as underweight, normal, overweight, and obese. Overweight and obesity have a negative impact on both the physical and psychological levels of wellbeing during childhood and adolescence. Research on African and South African children living in rural areas on the body composition and prevalence rates will provide an opportunity to understand the role of development in children and adolescents and the importance thereof. The purpose of this study was to determine the status of body composition and the effect of gender, age, and race on body composition. This dissertation comprises four chapters, of which one chapter can be read independently as it is written in the form of a research article. MAIN FINDINGS A literature review was conducted to gain more insight regarding body composition status of children throughout the world, and in Africa and South Africa, and the role that body composition plays in children and adolescents. The importance of these aspects is highlighted and discussed in Chapter Two. Cross-sectional data on a total of 280 learners (109 boys and 171 girls) aged 14 years, who are part of the Physical Activity Longitudinal Study from the Tlokwe municipality area, are participants in the study. Body mass, stature, and skinfolds were used to determine body composition and body mass index of the participants. All data was analysed using SPSS Version 21.0 (SPSS Inc., 2012). The statistical level was set at p-value ≤ 0.05. The results of this study indicate that out of 280 learners 13.1% are overweight, 29.1% normal weight and 57.8% underweight. Boys had a lower overweight value when compared to the girls (9.1% vs 15.7%). In addition, the results show that African girls had a higher prevalence for overweight (15.8% vs 15.4%) than their Caucasian counterparts. As for the impact of gender, age and race-independent effects on body composition or BMI, the results also show no significant (p ≥ 0.05) age-independent effect on body composition measures of percentage body fat, sum of six skinfolds, fat free mass and waist-to-height ratio. In conclusion, overweight and obesity is a growing problem among children and adolescents, especially African girls and Caucasian girls in the Tlokwe municipality. Furthermore, recommendations are made about the implementation of school-screening programmes in semi-urban areas. The role of the government, parents, and teachers, and the importance of health professionals must also be considered. / MSc (Biokinetics), North-West University, Potchefstroom Campus, 2015

This study compared three indirect calorimetry determinations, as kcals/minute, over three consecutive days on 28 healthy, sedentary women of varying body composition. No significant within-individual variation for VO2, CO2, respiratory quotient (RQ), or Kcals/minute was found among the three days. A low coefficient of variation (3.4 +/- 3%) and a relatively small standard deviation in mean Kcals/day (1383 +/- 214) suggests possibly one or only a few measures are necessary for predicting resting metabolic rate (RMR) within a range applicable for clinical use. There were strong correlations of body weight and body composition variables (fat and LBM) with RMR. Knowing both LBM and fat mass increased the ability to predict RMR significantly over the prediction with either variable alone. The Harris Benedict equation over-predicted RMR by 11.1% compared to RMR measured by indirect calorimetry. When equations are based on body weight, rather than LBM, metabolic rate may be over-predicted in obese populations.

published_or_final_version / Sports Science / Master / Master of Science in Sports Science

Whole-body bioelectrical impedance analysis (BIA) was evaluated for its reliability and accuracy in estimating body composition in children and youth. The established electrical principle for estimating volume in a geometrical system from conductor-length('2) divided by impedance is the basis for the use of this method in humans. The hypothesis that body-height('2) divided by the resistance component of impedance (resistance index) can be used to estimate total body water (TBW), fat free body (FFB), and percent fat (%FAT) was tested. Validation studies in adults indicate BIA is a reliable and fairly accurate method of estimating TBW, FFB, and %FAT but no testing has been completed on children. The subjects were 103 nonobese and obese anglo males and females from 10 to 14 years old. Within-day reliability of resistance and reactance was assessed by analysis of variance with built-in comparisons. Between-day reliability for all measurements, made four to five weeks apart, was evaluated by test-retest correlation coefficients and paired t-tests. The criterion variables were FFB and %FAT estimated using equations developed for children and youth based on: (1) skinfolds, (2) body density, (3) TBW, (4) density and TBW, (5) density, TBW, and bone mineral content. Regression and multiple regression analyses were used to select the most accurate method of measuring FFB and %FAT and to determine the relationship among criterion variables and the following independent variables: resistance index alone and combined with sex, fatness category, sex x fatness, age, sexual maturation status, weight, anthropometric variables, and reactance. From this study the following conclusions were made: (1) BIA measurements were reliable, (2) resistance index had a linear relationship with FFB estimated from several criterion variables, (3) weight, sex, fatness category, sex x fatness, age, and sexual maturation status were significant variables for predicting criterion variables used in combination with resistance index but were not significant when anthropometric variables were included in the analysis, (4) prediction accuracy for FFB and %FAT from resistance index was fair (SEE 2.58 kg and 4.21%) and from resistance index plus anthropometric variables and reactance was good (SEE 1.88 kg and 3.26%) and similar to that from the best anthropometric variables alone (SEE 2.11 kg and 3.19%).