Die verband tussen obesiteit, fisieke aktiwiteit en enkele faktore ten opsigte van geson[d]heids-risikogedrag by stedelike hoërskoolleerlinge in Namibië

Abstract

The aim of this study was to establish firstly, whether a lack of physical activity has a practical significant (w>0, 5) negative influence upon the occurrence of overweight and obesity among urban high school pupils in Namibia and secondly, if participation in physical activity has a practical significant (w>0, 5) positive influence upon the health risk behaviour amongst these pupils. The study was approved by the Namibian Department of Education and, after permission had been granted by the different school principals, informed permission was given by the parents/guardians of the pupils and the necessary agreement forms were signed. The children were fully informed as to which research procedures would be followed. A total of 294 adolescents between the ages of 14 and 18 years (boys n=133; girls n=161) residing in the urban areas of Windhoek and of different race groups (white n=145; black n=129; other ethnic groups n=9) were involved in the study. Anthropometrical data was gathered and body length and mass, triceps skin fold, sub-scapular skin fold and calf skin fold were measured. The body mass index (BMI) and the percentage of body fat was determined with regards to anthropometrical data. Physical activity levels as well as the health risk behaviour of the children were established with the assistance of "Youth Risk Behaviour Survey (YRBS)" self assessment questionnaire. Use was made of "Statistica for Windows Version 6" software package (Statsoft 2003) for data processing. Descriptive statistics have been analysed and two-way frequency tables were also utilized - firstly, to determine the connection between physical activity, overweight and obesity and secondly the relationship between physical activity and health risk behaviour. Since it cannot be positively stated that random sampling was not absolutely equable, use was made of effect evaluation to determine if the stated relationships are meaningful in practice (Steyn, 2002). Regarding body mass and body length, it seems to be clearly evident that, as the age increased, a constant decrease can be observed in the 14 to 18 year olds at both these two anthropometrical variables. The same tendency may also be observed with regard to the body mass index (BMI). Both the 18 year old boys and girls exhibited the largest average percentage body fat and the results further show that the body composition of the largest number of the entire group, boys (54%) and girls (42%), could be classified as normal with 8% of the boys overweight and 6% obese, whilst 26% of the girls were overweight and 30% obese. Results regarding the body composition of the girls are of such a nature as to cause alarm, as the whole scenario means that 56% of the girls can be classified as overweight or obese, which represents more than half of the entire group. The greater percentage (48%) of the complete group of boys (n=133) were moderately active, 37% highly active and 15% low active. Of the group of girls (n=161) the largest percentage of 47% could be classified as moderately active, with 27% highly active and 26% low active. A tendency was observed that there is a constant increase in decreased activity amongst the 14 to 18 year old girls. The older the girls become, the greater the number that are not very active. Another tendency observed, was that the overweight and obese boys arid girls were not very keen on physical activity and the older they got the less they took part in physical activity. It is therefore very clear that the occurrence of overweight/obesity in these children has a negative effect in participation in physical activity. Regarding the connection between physical activity and health risk behaviour, participation only had a positive influence on certain of the aspects (suicide and drugs) with the boys. The fact that amongst the boys physical activity did not have such a positive influence on smoking, sexual behaviour and alcohol abuse, can possibly be described firstly to peer pressure and secondly to social behaviour. Amongst the girls participation in physical activity did have a positive influence upon the smoking habits, sexual behaviour, suicide tendencies and alcohol as well as drug abuse.