Ultra-processed foods (UPFs) are industrial formulations made largely or entirely from substances extracted from foods or synthesised in laboratories. According to the NOVA classification system (Monteiro et al. 2018), they include refined starches, added sugars, hydrogenated oils, flavour enhancers, emulsifiers and preservatives. (1) These ingredients are rarely used in home cooking and are designed to enhance taste, shelf life, and convenience.

Common examples include sugary breakfast cereals, packaged snacks, instant noodles, soft drinks, processed meats and ready meals. Some products marketed as healthy, such as baby food pouches and flavoured yoghurts, also fall into this category.

UPFs account for a significant proportion of children's caloric intake globally. In the UK, toddlers get approximately 47% of their daily energy from UPFs by 21 months, increasing to 59% by age seven. School meals contribute further, with 64% of calories coming from UPFs. (2) In the US, UPFs make up nearly 70% of children's calories. (3) Similar trends are observed in Brazil, Chile and parts of Europe. Socioeconomic disparities exacerbate this issue, with disadvantaged families consuming higher proportions of UPFs due to affordability and accessibility. (4)

UPFs are typically high in energy density and low in nutrient density. They contain excessive amounts of added sugars, saturated and trans fats and sodium, while lacking fibre, protein and essential vitamins and minerals. Additives such as emulsifiers, artificial sweeteners, and colourants may have unknown long-term health effects. (5) Their hyper-palatable design encourages overconsumption and displaces healthier food options.

Numerous studies link UPF consumption to a range of adverse health outcomes in children:

• Obesity and overweight: UPFs contribute to excessive calorie intake and poor satiety, increasing the risk of obesity from early childhood into adulthood. (6)

• Metabolic disorders: Diets high in UPFs are associated with insulin resistance, type 2 diabetes, dyslipidaemia and non-alcoholic fatty liver disease.

• Dental and gut health: High sugar content promotes dental caries, while additives may disrupt the gut microbiome, leading to inflammation.(7)

• Cognitive and behavioural outcomes: UPFs are linked to ADHD-like symptoms, emotional instability and poorer academic performance.(8)

• Immune and respiratory health: UPFs may contribute to low-grade inflammation and increased incidence of asthma and bronchitis. (9)

• Long-term disease risk: Associations have been found with cancer, mental health disorders, sleep disturbances, and early mortality.

Early exposure to UPFs can shape taste preferences and eating habits, potentially leading to lifelong reliance on processed foods. Their soft texture may impair chewing strength and jaw development. Parental feeding styles also influence consumption patterns, with permissive approaches linked to higher UPF intake.

Several factors contribute to the widespread consumption of UPFs among children:

• Marketing: Aggressive advertising targets children through media and packaging. (10)

• Convenience and cost: UPFs are affordable, shelf-stable and easy to prepare.

• Misleading labels: Health claims on packaging can obscure the true nutritional quality.

• School environments: UPFs dominate school meals due to logistical and financial constraints. (11)

Governments and health organizations have implemented various strategies to curb UPF consumption:

• Labelling: Front-of-package warnings inform consumers about high sugar, salt, or fat content.(12)

• Marketing restrictions: Some countries limit advertising of UPFs to children (Norway, Quebec (Canada) and Ireland.)

• School food reform: Policies aim to replace UPFs with minimally processed alternatives. (13)

• Economic measures: Subsidies for whole foods and taxes on UPFs are being explored. (14)

• Education: Campaigns and school programs promote food literacy and healthy eating habits. (15)

Families and allied health professionals play a critical role in shaping children's dietary habits:

• Delay UPF introduction during infancy and promote breastfeeding.

• Prepare meals using whole ingredients and involve children in food choices.

• Educate parents on reading labels and identifying UPFs.

• Encourage structured meals and limit exposure to food advertising.

• Advocate for healthier food environments in schools and communities.

Observational studies consistently link UPFs with obesity, metabolic disorders and behavioural issues. Randomised trials in adults show increased calorie intake and weight gain on UPF-rich diets, even when macronutrients are matched. Longitudinal studies in children suggest that early UPF exposure predicts continued consumption and poorer health outcomes. While causality is complex, mechanisms involving food reward, gut dysbiosis and hyper-palatability are well documented.

1. Monteiro, C. A., et al. (2019). Ultra-processed foods: what they are and how to identify them. Public Health Nutrition, 22(5), 936-941.

2. Conway, R. E., Heuchan, G. N., Heggie, L., Rauber, F., Lowry, N., Hallen, H., & Llewellyn, C. H. (2024). Ultra-processed food intake in toddlerhood and mid-childhood in the UK: cross sectional and longitudinal perspectives. European journal of nutrition, 63(8), 3149–3160. https://doi.org/10.1007/s00394-024-03496-7

3. Wang, L., et al. (2021). Trends in consumption of ultra-processed foods among US youths. JAMA, 326(6), 519-530.

4. Darmon, N., & Drewnowski, A. (2008). Does social class predict diet quality? The American Journal of Clinical Nutrition, 87(5), 1107-1117.

5. Chassaing, B., et al. (2015). Dietary emulsifiers impact the mouse gut microbiota promoting colitis and metabolic syndrome. Nature, 519(7541), 92-96.

6. Costa, C. d. S., et al. (2018). Consumption of ultra-processed foods and body fat during childhood and adolescence: a systematic review. Public Health Nutrition, 21(1), 148-159.

7. Moynihan, P., & Kelly, S. (2014). Effect on caries of restricting sugars intake. Journal of Dental Research, 93(1), 8-18.

8. Jacka, F. N., et al. (2011). Associations between diet quality and depressed mood in adolescents. ANZJP, 45(2), 137-146.

9. Tristan Asensi, M., Napoletano, A., Sofi, F., & Dinu, M. (2023). Low-Grade Inflammation and Ultra-Processed Foods Consumption: A Review. Nutrients, 15(6), 1546. https://doi.org/10.3390/nu15061546

10. Cairns, G., Angus, K., Hastings, G., & Caraher, M. (2013). Systematic reviews of the evidence on the nature, extent and effects of food marketing to children. Appetite, 62, 209-215.

11. Parnham, J. C., Millett, C., & Vamos, E. P. (2023). School meals in the UK: ultra-processed, unequal and inadequate. Public health nutrition, 26(1), 297–301. https://doi.org/10.1017/S1368980022002336

12. Taillie, L. S., et al. (2020). Front-of-package nutrient warning labels: a scoping review. Nutrients, 12(2), 569.

13. Government response to the House of Lords Food, Diet and Obesity Committee’s report 'Recipe for health: a plan to fix our broken food system' - GOV.UK

14. Government response to the House of Lords Food, Diet and Obesity Committee’s report 'Recipe for health: a plan to fix our broken food system' - GOV.UK

15. Evans, C. E. L., et al. (2012). Systematic review and meta-analysis of school-based interventions to improve daily fruit and vegetable intake in children. AJCN, 96(4), 889-901.

16. Bennett, G., Young, E., Butler, I., & Coe, S. (2021). The impact of lockdown during the COVID-19 pandemic (Bennett et al., 2021) on dietary habits in various population groups: a scoping review. Frontiers in Nutrition, 8, 626432.

17. Harris, J. L., et al. (2009). Evaluating fast food nutrition and marketing to youth (Harris et al., 2009). Yale Rudd Center for Food Policy & Obesity.

18. Luiten, C. M., et al. (2016). Ultra-processed foods have the worst nutrient profile (Luiten et al., 2016). Public Health Nutrition, 19(3), 530-538.

19. Monteiro, C. A., Cannon, G., Moubarac, J. C., Levy, R. B., Louzada, M. L. C., & Jaime, P. C. (2018). The UN Decade of Nutrition, the NOVA food classification and the trouble with ultra-processing. Public health nutrition, 21(1), 5–17. https://doi.org/10.1017/S1368980017000234

20. Monteiro, C. A., et al. (2013). Ultra-processed products are becoming dominant in the global food system. Obesity Reviews, 14, 21-28.

21. World Health Organization (WHO). (2021). Obesity and overweight (World Health Organization, 2021). Retrieved from [URL]