Call number: LD2668 .T4 1985 S22 / Master of Science

Thesis (Mnutr)--Stellenbosch Univresity, 2004. / ENGLISH ABSTRACT: INTRODUCTION: The aim of this study was to investigate post-immigration BMI changes in a South African immigrant population and how dietary intake and habitual physical activity reflect these changes. The study was designed as a cross-sectional, observational survey. Thirty-six volunteers aged 20 - 50 years were included in the sample. Volunteers were South African immigrants in the Atlanta area, USA, who have lived in the USA for more than 6 months but less than 5 years. METHOD: Subjects were required to complete four questionnaires including a selfadministered socia-demographic, physical activity and food frequency questionnaire. The weight history questionnaire containing measurements including height, weight and waist circumference was completed by the investigator. RESULTS: A significant increase in BMI was indicated for both male (p=0.036) and female (p=0.0009) subjects. The increase in BMI for two age categories, 20-29 years (p = 0.018) and 30-39 years (p = 0.006), was also significant. Forty five percent of females reported an energy intake above the Estimated Energy Requirement (EER) for active individuals. Reported saturated fatty acid intake (13% of TE) exceeded the Acceptable Macronutrient Distribution Range (AMOR). The prevalence of inadequate n-3 and n-6 PUFA as well as fibre intake was high, especially in men. Sixty four percent of the population had a 'low active' physical activity level (PAL). CONCLUSION: The observed increase in post-immigration BMI implies that the South African immigrant population, similar to other immigrant populations, has adopted to some extent, the lifestyle and dietary habits of the general US population. As a result, the South African immigrant population may also be subject to increased chronic disease risk. / AFRIKAANSE OPSOMMING: INLEIDING: Die doel van hierdie studie was om die veranderinge in liggaamsmassa index (LMI) wat met immigrasie gepaard gaan in In Suid-Afrikaanse immigrant populasie te ondersoek, asook hoe die populasie se dieet en fisieke aktiwiteit hierdie veranderinge reflekteer. Die studie was In dwarssnit, observasie opname. Die steekproef het bestaan uit 36 vrywilligers (20 - 50 jaar oud). Respondente was deel van In Suid-Afrikaanse immigrant populasie in die Atlanta area, VSA, wat vir langer as 6 maande en korter as 5 jaar in die VSA woonagtig was. METODE: Respondente is versoek om vier vraelyste te voltooi insluitende In sosiodemografiese, fisieke aktiwiteit, -en voedsel frekwensie vraelys. Antropometriese metings, insluitende massa, lengte en middelomtrek is deur die navorser op die massa geskiedenis vraelys aangeteken. RESULTATE: In Betekenisvolle toename in LMI vir beide mans (p=0.036) en vroue (p=0.0009) is gevind. Die toename in LMI vir respondente 20-29 jaar (p = 0.018) en 30- 39 jaar (p = 0.006) was ook betekenisvol. Vyf-en-veertig persent vroue se energie inname was hoër as die aanbevole daaglikse inname vir aktiewe individue. Die populasie se versadigde vetsuur inname (13% van totale energie) was hoër as die aanvaarbare makronutriënt verspreiding. Die prevalensie vir onvoldoende innname van n-3 en n-6 poli-onversadigde vetsure, asook vesel inname was hoog, veralonder mans. Vier-en-sestig persent van die populasie se fisieke aktiwiteit vlak is geklassifiseer as 'lae aktiwiteit' . GEVOLGTREKKING: Die waargenome toename in LMI impliseer dat die studie populasie, soortgelyk aan ander immigrant populasies, die lewensstyl en dieet gewoontes van die algemene Amerikaanse populasie tot In sekere mate aangeneem het en is dus ook onderhewig aan die gevolglike toename in risiko vir kroniese siekte van lewensstyl.

Metabolic syndrome (MetS) and abdominal obesity (AbOb) increase the risk of developing cardiovascular disease and diabetes. Energy restriction (ER), highprotein (PRO) intake and high-intensity interval training (HIT) can independently improve MetS and AbOb. However, ER reduces metabolically active lean body mass (LBM) in addition to body fat (BF). Purpose: To determine the effects of a 16-wk ER diet with 2 levels of PRO (15% or 25% of energy), plus HIT, on MetS risk factors, AbOb, and body composition in women. Methods: Sedentary, premenopausal women (age=35±10y) with AbOb (waist circumference [WC] ≥80cm) were randomized to a 16-wk ER diet (-300kcals/d) with 15% (15PRO; n=17) or 25% (25PRO; n=18) of energy from PRO, plus 45min/d, 3d/wk HIT and 45min/d, 2d/wk continuous moderate-intensity exercise (CME) (-200kcals/d). Diet and physical activity (PA) were assessed using 4-d weighed food and PA records, respectively; diet and exercise compliance were assessed monthly with multiple-pass 24-h recalls and weekly tracking logs. Body weight (BW), WC, DXA-assessed body composition (BF [%], BF [kg], trunk fat [kg], and LBM [kg]), blood lipids (total cholesterol [TC], high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], triglycerides [TG]), glycemic markers (fasting plasma glucose [FPG], insulin, and homeostatic model assessment for insulin resistance [HOMA-IR], beta cell function [HOMA-%β] and insulin sensitivity [HOMA-%S]) and resting blood pressure (BP) (systolic BP [SBP]; diastolic BP [DBP]) were assessed pre/post-intervention. Repeated measures analysis of variance and two sample t-tests were used at analyze the date. Results are reported as means±standard deviations. Results: There were significant time, but not group, differences in BW (-5.1±2.6kg, p=0.0141), WC (- 7.3±3.6cm, p<0.0001), TC (-18.1±17.4mg/dL, p<0.0001), LDL-C (12.2± 16.2mg/dL, p<0.0001), TG (-25.3±56.2mg/dL, p=0.0064), insulin (-2.1±4.2mg/dL, p=0.0048), HOMA-IR (-0.2±0.5, p=0.0062), HOMA-%β (-12.1±35.2%, p=0.0497), HOMA-%S (28.5±78.4%, p=0.0357), and SBP (-3±9mmHg, p=0.214). There were significant group x time differences in DBP (15PRO=-5±8mmHg, 25PRO=- 2±8mmHg; p=0.0024). There were no time or group differences in FPG or HDLC. There were significant time, but not group, effects on changes in BW (-5.1kg± 2.6, p<0.0001), BF (-3.3±1.6%, p<0.0001), and LBM (-0.6kg±1.5, p=0.0283). The 15PRO group lost more absolute whole BF (-5.2kg vs. -3.9kg, p=0.0355) and trunk fat (-3.1kg vs. -2.2kg) vs. the 25PRO group. Conclusion: Both diets significantly improved BW, AbOb, MetS risk factors, glycemic control, and BF (%); LBM (kg) loss was similar in both groups. Compared to the 15PRO diet had significantly greater absolute BF-kg and trunk fat-kg losses. Increased PRO intake did not improve AbOb or MetS risk beyond ER and HIT/CME. The impact of HIT/CME and the greater (-1.3kg) changes in BW in the 15PRO group may have contributed significantly to the changes in absolute BF and trunk fat. More research is needed to separate the impact of HIT/CME and weight loss from the impact of PRO during ER. / Graduation date: 2013 / Access restricted to the OSU Community at author's request from March 28, 2013 - March 28, 2014