Ultra-processed food consumption in New Zealand adolescents : the role of eating context : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Human Nutrition at Massey University, Albany, New Zealand

Abstract

Background: The adverse health outcomes and poor nutrient profiles of diets high in ultra processed food (UPF) is now widely recognised. Adolescents are particularly vulnerable to UPF exposure, due to high nutritional demands from rapid growth whilst building the foundations of lifelong eating habits. This study is the first to explore associations between eating contexts and UPF consumption and its contribution to energy intake by meal occasion amongst New Zealand (NZ) adolescents. A secondary objective examined associations between where foods were sourced from and UPF intake. Method: Dietary intake was assessed via a 24-hour (24-h) food recall, using the web-based technology Intake24 from a convenience sample of adolescents (n = 631), years 7-13 (aged 11-18), from schools within the Auckland, Bay of Plenty and Waikato regions in NZ. Foods were categorised into their level of processing using the NOVA classification system. Eating context was assessed by location consumed, with whom and whether an electronic device was present, across six mealtimes. Frequent eating patterns, classed as social dyads (where and with whom), were identified. Linear regression models were used to analyse the association between contextual factors and UPF intake in SPSS v.29.0. Results: UPF contributed 62.5% of total daily energy intake overall. UPF intake was significantly higher at snack times, particularly during evening snacks (79.6% of energy intake from that eating occasion). Meals consumed on the go (81.4%), in bedrooms (73.7%), and from fast-food outlets (74.0%) had the highest UPF contribution. Parental presence, especially at the family table, was associated with lower UPF intake (51.3%). Food sourced from convenience and fast-food outlets contributed > 80% UPF, while school lunch programmes were only 31.4%. Conclusion: Strategies to reduce UPF consumption in NZ adolescents could include encouraging family meals, reduced or healthier snacking, and increased eligibility and uptake of the government funded school lunch programme.