Relationship between physical activity with dietary intake and nutritional status of adolescent girls attending a private school in Durban

Abstract

Aim The purpose of this study was to investigate the nutritional status of adolescent girls attending a private high school in Durban and included an investigation of what food the girls consumed on a daily basis and an account of physical activity they participated in within a one-week period to determine a relationship between the variables.

Methods Adolescent girls were selected as part of a convenience study at a private high school. A total of 225 adolescent girls aged 13-18 years were surveyed for nutritional status and dietary intake as well as physical activity levels. The parent/ caregiver of each girl who participated was interviewed to ascertain socio-demographic indicators. Data was collected by interviewing the adolescent girls and the parents/ caregivers using pre-designed and pre-tested questionnaires. Weight and height were measured, physical activity levels were identified through the use of a physical activity questionnaire and socio-demographic data was collected by means of a questionnaire. Dietary intake data was gathered over two week days and one weekend day by using a 24-hour recall questionnaire and a food frequency questionnaire (FFQ).

Results The majority of the participants were from well-off, financially stable families with good living conditions and well-educated and employed parents/ caregivers who provided a more than adequate variety of food and regular meals every day. The girls were of normal BMI (72.2%) and collectively had a mean BMI of 21.9, lower than the South African national average found for adolescent girls. There was a surprising number of underweight individuals (12.6%) as compared to overweight girls (10.3%). Furthermore, 99.6 percent of the girls were of normal height-for-age (≥-2 <+3SD) but were consuming far less energy than is required for the allocated age category. Energy came from the normal recommended macronutrient range with fat being on the borderline higher end of the normal range and carbohydrates coming from the lower end of the normal range; protein sources were adequately consumed. Fruit and vegetable consumption was reported to be very low subsequently leading to the poor dietary fibre intake identified across the sample group. Supplementation is taken by nearly a third (32.7%) of the girls which may contribute to their overall nutritional wellbeing. Among the top twenty foods consumed, milk, sugar, bread, tea and lettuce were the top five foods in the order stated. Although a wide variety of foods was consumed across all nine food groups over a week period, a mean daily DDS was lower but still adequate with 5.5 and the quantity of foods consumed were not of a substantial enough amount leading to poor total energy consumed and some micronutrient levels such as calcium, magnesium and folate not being met.

All the participants were seen to be fairly physically active, performing a wide variety of sporting activities during school time and after school hours. The girls completed on average 199.64 minutes (SD±134.97) of physical activity per week, which is less than half of the WHO recommended physical activity minutes per week for adolescents. Significant correlations were seen between BMI and physical activity done on the weekend (p=0.041) and BMI and the amount of money spent on food per month (p=0.016) as well as extremely significant correlations between BMI and the number of minutes spent performing physical activities per week (p=0.002), as well as BMI and the amount of sport done over a one week period (p=0.005).

Conclusion The results confirm that a relationship does exist between the physical activity levels and nutritional status of the adolescent girls surveyed. The majority of the population had low physical activity levels as well as low energy intake, which was supported by an inadequate quantity of food items consumed; however, anthropometric measurements showed to be majority within normal parameters with cases of underweight girls being more prominent than overweight which may suggest that over- and/ or under-reporting may have occurred. A high dietary diversity indicated a higher nutrient intake suggesting the importance of a diversified diet.