Regular breakfast consumption among adolescents has been linked to decreased risk of obesity and chronic diseases, improved cognition and improved nutrient intake in adolescents. Despite this, research has indicated that adolescent breakfast consumption is declining globally. Adolescents are at particularly high-risk for health compromising behaviours such as increased fast food consumption, increased sedentary levels and frequent breakfast skipping. Research shows that lifestyle and behaviour habits which are entrenched during adolescence are likely to remain throughout adulthood. The reported prevalence of breakfast skipping among different adolescent population groups in South Africa ranges from 13 to 36%. However, little is known about breakfast behaviour among adolescents in the South African context. Studying breakfast behaviour and the mechanism by which breakfast influences positive health outcomes creates an understanding of the magnitude of the problem to be addressed and guides effective recommendations for public health guidelines. The aim of the present study was to determine the proportion and quality of breakfast intake among adolescents attending public secondary schools in Potchefstroom and its surrounding areas in the Northwest Province, and to determine the effect of breakfast intake and quality on overall diet quality and other lifestyle behaviours. A cross sectional quantitative study design was used. Adolescents in grades nine to eleven (n = 254) were randomly selected from seven public secondary schools across quintiles in Potchefstroom and its surrounding areas in the Northwest Province of South Africa. A basic self-administered demographic questionnaire was used. A single 24-hour recall using the four-stage multiple pass method was conducted to obtain information on breakfast and dietary intake for the day. A self-administered questionnaire was used to select the type of breakfast usually consumed by the adolescents. Height and weight were measured by a level one anthropomotrist. Dietary data was analysed using the Medical Research Council Food Composition Tables. Breakfast quality was measured through the allocation of a breakfast quality score and the Diet Quality Index Revised (DQI-R) was used to assess the quality of the overall diet. Associations between breakfast intake and categorical characteristics were assessed by either the Chi-squared Test or Fisher’s Exact Test. Spearman correlations were used to assess the associations between breakfast quality score and continuous variables. The threshold for statistical significance was set at 0.05. The Goldberg cut-off was applied to exclude over- and under-reporters. Information was collected for 244 adolescents with a mean age of 17.5 years (± 2.3). The proportion of breakfast intake and skipping was 81% and 19% respectively. The mean breakfast quality score was 3.1 out of a possible score of 5, indicating moderate breakfast quality which incorporates one of the Australian Guide to Healthy Eating (AGHE) food groups. Breakfast intake was influenced by race, and breakfast quality was influenced by participation in physical activity. Breakfast eaters and skippers showed no significant difference in diet quality score. Breakfast quality score was marginally associated with calcium intake (p<0.0001; r=0.418), phosphorous intake (p<0.0001; r=0.378) and total diversity score (p<0.0001; r=0.369). The foods most frequently consumed at breakfast were bread, milk, ready-to-eat cereal (RTEC) and maize porridge. In conclusion, breakfast skipping proportion was consistent with published South African data. The quality of the breakfast consumed among adolescents in the present study was moderate. Cultural and socio-environmental factors may influence breakfast intake and breakfast quality among adolescents. Breakfast intake did not influence diet quality, but the intake of certain foods at breakfast improved the mean scores for components of the DQI-R and improved the intake of key nutrients. It is recommended that the governmental departments responsible for the Integrated School Health Policy (ISHP) incorporate breakfast messaging into the nutrition education component of the ISHP. Facilitators involved in implementing the ISHP, such as School-based support teams, teachers and healthcare professionals are encouraged to continue the promotion of breakfast intake among adolescents. / MSc (Nutrition), North-West University, Potchefstroom Campus, 2014

Regular breakfast consumption among adolescents has been linked to decreased risk of obesity and chronic diseases, improved cognition and improved nutrient intake in adolescents. Despite this, research has indicated that adolescent breakfast consumption is declining globally. Adolescents are at particularly high-risk for health compromising behaviours such as increased fast food consumption, increased sedentary levels and frequent breakfast skipping. Research shows that lifestyle and behaviour habits which are entrenched during adolescence are likely to remain throughout adulthood. The reported prevalence of breakfast skipping among different adolescent population groups in South Africa ranges from 13 to 36%. However, little is known about breakfast behaviour among adolescents in the South African context. Studying breakfast behaviour and the mechanism by which breakfast influences positive health outcomes creates an understanding of the magnitude of the problem to be addressed and guides effective recommendations for public health guidelines. The aim of the present study was to determine the proportion and quality of breakfast intake among adolescents attending public secondary schools in Potchefstroom and its surrounding areas in the Northwest Province, and to determine the effect of breakfast intake and quality on overall diet quality and other lifestyle behaviours. A cross sectional quantitative study design was used. Adolescents in grades nine to eleven (n = 254) were randomly selected from seven public secondary schools across quintiles in Potchefstroom and its surrounding areas in the Northwest Province of South Africa. A basic self-administered demographic questionnaire was used. A single 24-hour recall using the four-stage multiple pass method was conducted to obtain information on breakfast and dietary intake for the day. A self-administered questionnaire was used to select the type of breakfast usually consumed by the adolescents. Height and weight were measured by a level one anthropomotrist. Dietary data was analysed using the Medical Research Council Food Composition Tables. Breakfast quality was measured through the allocation of a breakfast quality score and the Diet Quality Index Revised (DQI-R) was used to assess the quality of the overall diet. Associations between breakfast intake and categorical characteristics were assessed by either the Chi-squared Test or Fisher’s Exact Test. Spearman correlations were used to assess the associations between breakfast quality score and continuous variables. The threshold for statistical significance was set at 0.05. The Goldberg cut-off was applied to exclude over- and under-reporters. Information was collected for 244 adolescents with a mean age of 17.5 years (± 2.3). The proportion of breakfast intake and skipping was 81% and 19% respectively. The mean breakfast quality score was 3.1 out of a possible score of 5, indicating moderate breakfast quality which incorporates one of the Australian Guide to Healthy Eating (AGHE) food groups. Breakfast intake was influenced by race, and breakfast quality was influenced by participation in physical activity. Breakfast eaters and skippers showed no significant difference in diet quality score. Breakfast quality score was marginally associated with calcium intake (p<0.0001; r=0.418), phosphorous intake (p<0.0001; r=0.378) and total diversity score (p<0.0001; r=0.369). The foods most frequently consumed at breakfast were bread, milk, ready-to-eat cereal (RTEC) and maize porridge. In conclusion, breakfast skipping proportion was consistent with published South African data. The quality of the breakfast consumed among adolescents in the present study was moderate. Cultural and socio-environmental factors may influence breakfast intake and breakfast quality among adolescents. Breakfast intake did not influence diet quality, but the intake of certain foods at breakfast improved the mean scores for components of the DQI-R and improved the intake of key nutrients. It is recommended that the governmental departments responsible for the Integrated School Health Policy (ISHP) incorporate breakfast messaging into the nutrition education component of the ISHP. Facilitators involved in implementing the ISHP, such as School-based support teams, teachers and healthcare professionals are encouraged to continue the promotion of breakfast intake among adolescents. / MSc (Nutrition), North-West University, Potchefstroom Campus, 2014

Background: Dietary fat intake particularly of omega-3 and omega-6 fatty acids play an important role in growth and development and influence the risk of nutrition related non communicable diseases. These dietary intakes are reflected in the red blood cell (RBC) fatty acid profile. Aim: The aim of this study was to assess the fatty acid profile (%) of red blood cell membrane phospholipids in relation to the dietary intake of South African children aged 2 to 5 years, and of their mothers/caregivers from three communities, each with distinct dietary patterns. Method: In this cross-sectional observational study, approximately 105 children, aged: 2-5 years and their mother/caregivers were selected from three different geographical areas. These included; the urban community of De Aar (n=105), the urban coastal community Ocean View (n=93) and the rural community of Sekhukhune District (n=104). The red blood cell membrane total phospholipid fatty acid profile was determined by gas chromatography. A 24-hour dietary recall was done for each child and mother/caregiver as well as a socio-demographic questionnaire answered by each mother/caregiver. The mean and standard deviations of the RBC fatty acids were determined and compared through an analysis of variance (ANOVA) test followed by a Bonferroni post hoc test. Age and gender were controlled for in the children and age was controlled for in the mothers/caregivers. The median dietary intake (quartile range) was compared between communities by a Kruskal-Wallis test. The relationship between RBC membrane total phospholipid fatty acid profile and dietary fatty acid intake was done by stratifying the data for the three groups combined into tertiles according to RBC fatty acid profile and comparing the median (quartile range) of the dietary fatty acid intake in the different strata. Results: In the children, the total dietary fat, SFA and PUFA and omega-3 intake of De Aar (34.2%, 11.9%, 5.9% and 0.2% of energy, respectively) and Ocean View (33.0%, 11.2%, 7.4% and 0.2% of energy, respectively) was significantly different to Sekhukhune (19.9%, 6.5%, 3.0% and 0.1% of energy, respectively). Eicosaipentanoic (EPA) and docosahexaenoic (DHA) and α-linolenic acid (ALA) mean intake in children in all three sites was lower than recommended. In children from De Aar the RBC membrane total phospholipids contained significantly higher SFA and trans-fat percentages, while children in Sekhukhune District had significantly higher PUFA, omega-6 and omega-3 percentages. The linoleic acid (LA) profile in children from Ocean View was significantly higher than in those from De Aar and Sekhukhune District. The mother/caregivers’ dietary fat intake of total fat, SFA, PUFA and trans-fat was significantly higher in De Aar (31.7%, 10.5%, 6.3% and 0.2% of energy respectively) and Ocean View (37.4%, 12.1%, 8.5% and 0.59% of energy respectively) in comparison to Sekhukhune District (15.7%, 3.0%, 3.2% and 0.02% energy respectively). PUFA intakes were significantly higher in Ocean View (8.5% of energy). EPA, DHA and ALA dietary intakes were lower than recommended. The mother/caregiver’s RBC membrane total phospholipid SFA percentage was significantly higher in mothers/caregivers from De Aar and Ocean View whereas those from Sekhukhune District had significantly higher PUFA and omega-3 percentage. Conclusion: Differences particularly between the urban areas of De Aar and Ocean View and the rural area of Sekhukhune District were observed in dietary fat intake which was reflected in the red blood cell membrane total phospholipid fatty acid profile for children and mother/caregivers. Dietary omega-3 fatty acid intake was low in both children and mother/caregivers from all three study sites and is of concern. / MSc (Nutrition), North-West University, Potchefstroom Campus, 2014

Background: Dietary fat intake particularly of omega-3 and omega-6 fatty acids play an important role in growth and development and influence the risk of nutrition related non communicable diseases. These dietary intakes are reflected in the red blood cell (RBC) fatty acid profile. Aim: The aim of this study was to assess the fatty acid profile (%) of red blood cell membrane phospholipids in relation to the dietary intake of South African children aged 2 to 5 years, and of their mothers/caregivers from three communities, each with distinct dietary patterns. Method: In this cross-sectional observational study, approximately 105 children, aged: 2-5 years and their mother/caregivers were selected from three different geographical areas. These included; the urban community of De Aar (n=105), the urban coastal community Ocean View (n=93) and the rural community of Sekhukhune District (n=104). The red blood cell membrane total phospholipid fatty acid profile was determined by gas chromatography. A 24-hour dietary recall was done for each child and mother/caregiver as well as a socio-demographic questionnaire answered by each mother/caregiver. The mean and standard deviations of the RBC fatty acids were determined and compared through an analysis of variance (ANOVA) test followed by a Bonferroni post hoc test. Age and gender were controlled for in the children and age was controlled for in the mothers/caregivers. The median dietary intake (quartile range) was compared between communities by a Kruskal-Wallis test. The relationship between RBC membrane total phospholipid fatty acid profile and dietary fatty acid intake was done by stratifying the data for the three groups combined into tertiles according to RBC fatty acid profile and comparing the median (quartile range) of the dietary fatty acid intake in the different strata. Results: In the children, the total dietary fat, SFA and PUFA and omega-3 intake of De Aar (34.2%, 11.9%, 5.9% and 0.2% of energy, respectively) and Ocean View (33.0%, 11.2%, 7.4% and 0.2% of energy, respectively) was significantly different to Sekhukhune (19.9%, 6.5%, 3.0% and 0.1% of energy, respectively). Eicosaipentanoic (EPA) and docosahexaenoic (DHA) and α-linolenic acid (ALA) mean intake in children in all three sites was lower than recommended. In children from De Aar the RBC membrane total phospholipids contained significantly higher SFA and trans-fat percentages, while children in Sekhukhune District had significantly higher PUFA, omega-6 and omega-3 percentages. The linoleic acid (LA) profile in children from Ocean View was significantly higher than in those from De Aar and Sekhukhune District. The mother/caregivers’ dietary fat intake of total fat, SFA, PUFA and trans-fat was significantly higher in De Aar (31.7%, 10.5%, 6.3% and 0.2% of energy respectively) and Ocean View (37.4%, 12.1%, 8.5% and 0.59% of energy respectively) in comparison to Sekhukhune District (15.7%, 3.0%, 3.2% and 0.02% energy respectively). PUFA intakes were significantly higher in Ocean View (8.5% of energy). EPA, DHA and ALA dietary intakes were lower than recommended. The mother/caregiver’s RBC membrane total phospholipid SFA percentage was significantly higher in mothers/caregivers from De Aar and Ocean View whereas those from Sekhukhune District had significantly higher PUFA and omega-3 percentage. Conclusion: Differences particularly between the urban areas of De Aar and Ocean View and the rural area of Sekhukhune District were observed in dietary fat intake which was reflected in the red blood cell membrane total phospholipid fatty acid profile for children and mother/caregivers. Dietary omega-3 fatty acid intake was low in both children and mother/caregivers from all three study sites and is of concern. / MSc (Nutrition), North-West University, Potchefstroom Campus, 2014

This study examined the energy dependence of cancer cells. Glucose was found to be their main energy source. It seems possible to use this dependence to advantage in the fight against cancer. A novel experiment to reduce the blood glucose supply and utilisation was proposed. It entailed caloric restriction, suppression of glucose secretion by the liver as well as suppression of stress hormones (which elevates glucose levels). This minimises the blood glucose value. As a last step, anti-insulin is provided to inhibit cancer cells to utilise the glucose. The cancer cells are thus deprived of their main energy source. This should lead to a reduction or elimination of tumours and will aid in preventing their development. Although feasible, this method turned out to be too expensive to perform the necessary clinical trials to prove the hypothesis. Next, the focus shifted to cancer prevention. The human energy system was analysed with the goal to reduce the circulating glucose level. The main focus here was metabolised CHO energy consumption. A previously proposed unit – the Equivalent Teaspoon Sugar, or ets , was used to quantify energy with. It was shown that cancer risk increases significantly when the recommended ets consumption per day is exceeded. Furthermore, it was shown that including fibre in a meal reduces the ets value of the meal. One gram of fibre leads to a reduction of around 0.6 ets . The link between exercise, stress, fibre, their resulting blood glucose levels and cancer were quantified in terms of ets . Exercise expends ets , while stress causes the liver to secrete more ets . Experimental data was analysed to confirm the relationships. In conclusion an equation was formulated to describe the combined effect of all these elements on the energy system. One’s total daily ets consumption can be obtained from the equation, and it was linked to one’s cancer risk. Adapting a lifestyle that ensures the correct daily ets intake will lead to a significant reduction in cancer risk. This study proved that cancer cells are very dependent on sugar and a restriction of this energy source forces them into regression. Using this knowledge to advantage may help in the combat one of the biggest killers of our time – cancer. / Thesis (Ph.D. (Electrical and Electronic Engineering))--North-West University, Potchefstroom Campus, 2012

This study examined the energy dependence of cancer cells. Glucose was found to be their main energy source. It seems possible to use this dependence to advantage in the fight against cancer. A novel experiment to reduce the blood glucose supply and utilisation was proposed. It entailed caloric restriction, suppression of glucose secretion by the liver as well as suppression of stress hormones (which elevates glucose levels). This minimises the blood glucose value. As a last step, anti-insulin is provided to inhibit cancer cells to utilise the glucose. The cancer cells are thus deprived of their main energy source. This should lead to a reduction or elimination of tumours and will aid in preventing their development. Although feasible, this method turned out to be too expensive to perform the necessary clinical trials to prove the hypothesis. Next, the focus shifted to cancer prevention. The human energy system was analysed with the goal to reduce the circulating glucose level. The main focus here was metabolised CHO energy consumption. A previously proposed unit – the Equivalent Teaspoon Sugar, or ets , was used to quantify energy with. It was shown that cancer risk increases significantly when the recommended ets consumption per day is exceeded. Furthermore, it was shown that including fibre in a meal reduces the ets value of the meal. One gram of fibre leads to a reduction of around 0.6 ets . The link between exercise, stress, fibre, their resulting blood glucose levels and cancer were quantified in terms of ets . Exercise expends ets , while stress causes the liver to secrete more ets . Experimental data was analysed to confirm the relationships. In conclusion an equation was formulated to describe the combined effect of all these elements on the energy system. One’s total daily ets consumption can be obtained from the equation, and it was linked to one’s cancer risk. Adapting a lifestyle that ensures the correct daily ets intake will lead to a significant reduction in cancer risk. This study proved that cancer cells are very dependent on sugar and a restriction of this energy source forces them into regression. Using this knowledge to advantage may help in the combat one of the biggest killers of our time – cancer. / Thesis (Ph.D. (Electrical and Electronic Engineering))--North-West University, Potchefstroom Campus, 2012

Summaries in Afrikaans and English / Die doel van hierdie ondersoek was om te bepaal watler faktore die grootste bydrae tot sportprestasie lewer. Met die literatuurstudie is die verskillende faktore wat sportprestasie beinvloed, geidentifiseer en verder ondersoek en beskryf. Daar is gevind dat 'n wye verskeidenheid faktore bestaan wat atletelsportdeelnemers se prestasie positief of negatief kan beinvloed. 'n Empiriese ondersoek is uitgevoer waarby 'n aantal atlete/sportdeelnemers, wat aan verskeie sportsoorte deelneem, betrek is. Die afrigters van hierdie atlete/sportdeelnemers is oak by die ondersoek betrek. Eerstens is bepaal watter faktore, volgens die atlete/sportdeelnemers, die grootste bydrae tot hul sportprestasie lewer. Daama is hierdie geidenlifiseerde faktore aan 'n regressieanalise onderwerp om te bepaal walter faktor/e die grootste en belangrikste bydrae tot sportprestasie lewer. Die resultate het getoon dat hierdie faktore soos volg is: motivering, afrigter, kommunikasie, selfvertroue, aanleg en dieet / The purpose of this study was to determine which factors contribute significantly to sports achievement. In the literature study, different factors with an underlying effect on sports achievement were identified, explained and further investigated. A wide variety of factors bearing positive as well as negative effect on athletes'/sport participants' achievement were found. An empirical study was carried out in which a number of athletes/sport participators were involved. The coaches of these athletes/sport participants were also included. The factors that play a major contributing role in these athletes/sport participants' sports achievement were primarily determined. Thereafter the identified factors were further investigated through the use of a regression analysis to ascertain which ones contribute the most to sports achievement. The results indicated that these factors are as follows: motivation, coach, communication, self-confidence, talent and diet. / Educational Studies / M.Ed. (met spesialisering in Voorligting)

Summaries in Afrikaans and English / Die doel van hierdie ondersoek was om te bepaal watler faktore die grootste bydrae tot sportprestasie lewer. Met die literatuurstudie is die verskillende faktore wat sportprestasie beinvloed, geidentifiseer en verder ondersoek en beskryf. Daar is gevind dat 'n wye verskeidenheid faktore bestaan wat atletelsportdeelnemers se prestasie positief of negatief kan beinvloed. 'n Empiriese ondersoek is uitgevoer waarby 'n aantal atlete/sportdeelnemers, wat aan verskeie sportsoorte deelneem, betrek is. Die afrigters van hierdie atlete/sportdeelnemers is oak by die ondersoek betrek. Eerstens is bepaal watter faktore, volgens die atlete/sportdeelnemers, die grootste bydrae tot hul sportprestasie lewer. Daama is hierdie geidenlifiseerde faktore aan 'n regressieanalise onderwerp om te bepaal walter faktor/e die grootste en belangrikste bydrae tot sportprestasie lewer. Die resultate het getoon dat hierdie faktore soos volg is: motivering, afrigter, kommunikasie, selfvertroue, aanleg en dieet / The purpose of this study was to determine which factors contribute significantly to sports achievement. In the literature study, different factors with an underlying effect on sports achievement were identified, explained and further investigated. A wide variety of factors bearing positive as well as negative effect on athletes'/sport participants' achievement were found. An empirical study was carried out in which a number of athletes/sport participators were involved. The coaches of these athletes/sport participants were also included. The factors that play a major contributing role in these athletes/sport participants' sports achievement were primarily determined. Thereafter the identified factors were further investigated through the use of a regression analysis to ascertain which ones contribute the most to sports achievement. The results indicated that these factors are as follows: motivation, coach, communication, self-confidence, talent and diet. / Educational Studies / M.Ed. (met spesialisering in Voorligting)