Oral Presentation Australian and New Zealand Obesity Society Annual Scientific Conference 2026

Trajectories of discretionary and ultra-processed food intakes and their determinants among young Australian children (143588)

Tinsae Shemelise Tesfaye 1 2 , Priscila Machado 2 , Miaobing Zheng 1
  1. School of Health Sciences, University of New South Wales, Kensington, New South Wales, Australia
  2. Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia

Background/Aims: Discretionary foods and ultra-processed foods (UPFs) are related but distinct measures of unhealthy diets, yet little is known about how they compare in early childhood. This study examined their intake trajectories, determinants, and associations with BMI z-score trajectories from ages 9 months to 5 years.

Methods: Data of 432 children from the Melbourne InFANT Program were used. Group-based trajectory modelling identified trajectories of discretionary foods and UPFs intakes (percentage total energy intake, %E) and BMI z-scores assessed at ages 9 months, 18 months, 3.5 years, and 5 years. Multivariable logistic regression examined factors associated with identified intake trajectories and their associations with BMI z-score trajectories.

Results: Three discretionary food intake trajectories groups were identified: “high” (5–42%E; 14% of the sample), “mid” (4–24%E; 59%) and “low” 27% (2–5%E; 27%). Two UPF intake trajectory groups were identified: “low increasing” (22–42%E, 43%) and “high early-declining” (70–49%E, 57%). Three BMI z-score trajectory groups of low, mid, and high emerged. Maternal pre-pregnancy BMI (≥25 kg/m2) was associated with higher odds of children following the “high” discretionary food intake trajectory. Children of women with university education had lower odds of following the “high early-declining” UPF trajectory than children of women without a university education. Children breastfed for < 6 versus ≥ 6 months and children of employed versus unemployed women were associated with higher odds of following the “high early-declining” UPF intake trajectory. No significant associations were observed between intake trajectories of discretionary food or UPF intakes with BMI z-score trajectories.

Conclusion: Discretionary foods and UPF classifications captured different intake trajectories and determinants during early childhood, but neither was associated with BMI z-score trajectories. These findings suggest that discretionary foods and UPFs capture distinct aspects of children's diets and should not be used interchangeably