The intake and quality of breakfast consumption in adolescents attending public secondary schools in the North West province, South Africa

Testing an online measure of portion size selection: a pilot study concerned with the measurement of ideal portion size

BACKGROUND

Portion size is known to be a key driver of food intake. As consumed portions are often pre-planned, 'ideal portion size'-an individual's preferred meal size selected prior to eating-has been identified as a strong predictor of actual consumption. However, assessments of ideal portion size have predominantly relied on laboratory-based computer tasks, limiting use online. Therefore, this cross-sectional study sought to pilot test the validity of a web-based tool to measure ideal portion size.

METHODS

In an online study (N = 48), participants responded to images of a range of foods. Each food was photographed in a series of different portions and loaded into an 'image carousel' that would allow participants to change the size of the displayed portion by moving a slider left-to-right. Using this image carousel, participants selected their ideal portion size. They also completed measures of expected satiety and expected satiation and self-reported their age and body mass index (BMI). A non-parametric correlation matrix was used to explore associations between ideal portion size and identified predictors of food intake.

RESULTS

Supporting convergent validity of this measure, ideal portion size was significantly correlated with expected satiety (rs = .480) and expected satiation (rs = -.310) after controlling for effects of baseline hunger and fullness, consistent with past research. Similarly, supporting divergent validity of this measure, ideal portion size was not significantly correlated with age (rs = -.032) or BMI (rs = -.111,).

CONCLUSIONS

Pilot results support the validity of this web-based portion size selection tool used to measure ideal portion size, though further research is needed to validate use with comparisons to actual food intake.

The Food and Nutrition Environment at Secondary Schools in the Eastern Cape, South Africa as Reported by Learners

Overweight and obesity are growing concerns in adolescents, particularly in females in South Africa. The aim of this study was to evaluate the food and nutrition environment in terms of government policy programs, nutrition education provided, and foods sold at secondary schools in the Eastern Cape province. Sixteen schools and grade 8-12 learners (N = 1360) were randomly selected from three health districts comprising poor disadvantaged communities. Based on age and sex specific body mass index (BMI) cut-off values, 13.3% of males and 5.5% of females were underweight, while 9.9% of males and 36.1% of females were overweight or obese. The main food items purchased at school were unhealthy energy-dense items such as fried flour dough balls, chocolates, candies, and crisps/chips. Nutrition knowledge scores based on the South African food-based dietary guidelines (FBDGs) were poor for 52% to 23.4% learners in Grades 8 to 12, respectively. Female learners generally had significantly higher nutrition knowledge scores compared to their male counterparts (p = 0.016). Questions poorly answered by more than 60% of learners, included the number of fruit and vegetable portions required daily, food to eat when overweight, foods containing fiber, and importance of legumes. It was noted that the majority of teachers who taught nutrition had no formal nutrition training and their responses to knowledge questions were poor indicating that they were not familiar with the FBDGs, which are part of the curriculum. Nutrition assessment as part of the Integrated School Health Program was done on few learners. Overall however, despite some challenges the government national school meal program provided meals daily to 96% of learners. In general, the school food and nutrition environment was not conducive for promoting healthy eating.

Breakfast eating patterns and drivers of a healthy breakfast composition

Breakfast has long been described as the most important meal of the day. While breakfast habits and their consequences on children's health and performance are well documented, studies on the adult population are lacking. The present study will fill this gap, providing a comprehensive picture of the Swiss breakfast habits and insights into the determinants of a healthy breakfast composition. Data were collected through a postal survey sent out to a randomly selected sample of 1917 German-speaking Swiss residents, yielding a final sample size of N = 460. Breakfast habits were disclosed, and individual breakfast healthiness scores were assessed by two nutrition specialists. A multiple regression analysis was then performed to investigate the influence of several motivational, socio-demographic, health- and knowledge-related determinants on breakfast healthiness. The sample showed recommendable habits in terms of consumption frequency and quite traditional eating patterns, illustrated by the prevalence of continental breakfasts and equally marked by the frequent consumption of dairy products. Overall, the Swiss breakfast composition is moderately healthy, lacking fruits and whole grain products. Paying attention to healthy food choices in general, higher education level, being a woman and reporting to be fit are factors linked to a healthier breakfast composition; while preferences for low-fat, familiar or convenient foods are correlated to less healthy patterns. Given the parallel between the determinants of a healthy breakfast composition and those of a healthy diet and taking some limiting factors, such as consumers preference for convenience and strong habits, into account, we support the current nutritional advice focusing on balancing the diet over the day or the week rather than on recommendations dedicated to specific meals.

Restricting the marketing of foods and non-alcoholic beverages to children in South Africa: are all nutrient profiling models the same?

The WHO has called for governments to improve children’s food environment by implementing restrictions on the marketing of ‘unhealthy’ foods to children. Nutrient profiling (NP) models are used to define ‘unhealthy’ foods and support child-directed food marketing regulations. The aim of the present study was to assess the suitability of the South African NP model (SANPM), developed and validated for health claim regulations, for child-directed food marketing regulations. The SANPM was compared with four NP models specifically developed for such regulations. A representative list of 197 foods was compiled by including all foods advertised on South African free-to-air television channels in 2014 and foods commonly consumed by South African children. The nutritional information of the foods was sourced from food packaging, company websites and a food composition table. Each individual food was classified by each of the five NP models. The percentage of foods that would be allowed according to the different NP models ranged from 6 to 45 %; the models also varied considerably with regard to the type of foods allowed for marketing to children. The majority of the pairwise comparisons between the NP models yieldedκstatistics >0·4, indicating a moderate agreement between the models. An almost perfect pairwise agreement (κ=0·948) existed between the SANPM and the UK Food Standards Agency model (United Kingdom Office of Communication nutrient profiling model), a model extensively tested and validated for such regulations. The SANPM is considered appropriate for child-directed food marketing regulations in South Africa.