Adolescence is a critical life stage that is of considerable interest to nutritionists because it is a period of great physical, emotional, social and cognitive change. The dynamics of adolescence can have important influences on individual nutrition both in the short term and also in the post-adolescent period. It also creates challenges for the reliable and valid assessment of adolescent dietary behaviours, which is an important prerequisite for appropriate and effective nutrition interventions in this age group. In this issue, Whati et al.(Reference Whati, Senekal, Steyn, Lombard and Nel1) address this challenge in a paper that describes the development and validation of a norm-referenced performance-rating scale to interpret a nutrition knowledge test for use among urban adolescents in South Africa. The methodology they outline serves as a useful prototype for developing knowledge tests in this and other contexts. Vereecken et al.(Reference Vereecken, De Henauw, Maes, Moreno, Manios, Phillipp, Plada and De Bourdeaudhuij2) report on the development and testing of a short questionnaire to assess the determinants of healthy diets in Belgium, motivated by the need to be able to isolate determinants of dietary behaviours in order to effectively focus interventions.
Junk food
In many countries, adolescence is characterised by behaviours that reflect an assertion of individuality and distancing from adult/parental norms. Fast-food consumption is just one of the ways this is expressed. Bauer et al.(Reference Bauer, Larson, Nelson, Story and Neumark-Sztainer3) present a study of the socio-environmental, personal and behavioural predictors of fast-food intake among adolescents in the USA. Using a longitudinal cohort study method among a sample of Minnesota school students, they identify gender differences in predictors of fast-food consumption that provide important points for differential design of interventions that aim to reduce an undesirable reliance on this food category by adolescence. Energy-dense and nutrient-poor soft drinks are the beverage version of junk food and can be a major contributor to adolescents’ energy intakes. Hattersley et al.(Reference Hattersley, Irwin, King and Allman-Farinelli4) report on a qualitative study of focus groups among Australian university students that explores the determinants and patterns of soft drink consumption in young adults. They identify the importance of intrinsic qualities of caloric soft drinks among participants including taste, sugar and caffeine content, and note a number of gender differences. Purchasing of fast food was identified as a major predictor of soft drink consumption contributing to the all-round ‘junk meal’.
A need for more non-industry funded nutrition research
Research that is independent of vested interests is a central principle relating to the objectivity and validity of research. In this issue, Nkansah et al.(Reference Nkansah, Nguyen, Iraninezhad and Bero5) assess the relationship between research sponsorship, study results and conclusions in a sample of nineteen randomised controlled trials relating to Ca supplementation. While they report their study to be inconclusive with respect to this relationship, they point to the need for more non-industry research funding to enhance the validity of nutrition research. I suspect very few readers of this journal would disagree.
