July 17, 2024

expert reaction to study looking at ultra-processed food consumption in UK adolescents

A study published in the European Journal of Nutrition looks at ultra-processed food consumption in UK teens. 

Dr Aisling Daly RNutr, Lecturer in Nutrition, Oxford Brookes University, said:

“This research is very useful to determine the contribution of UPFs to the UK adolescent diet, a topic of increasing interest lately.  The authors clearly highlight some disparities in UPF consumption based on some gender, ethnic and socioeconomic factors, indicating certain groups who may be at higher risk of ill health because of this consumption.

“However, what is lacking from this research is the connection to other aspects of health, or other specific nutrients (e.g. fat and fibre), and therefore the actual/potential effect of this consumption.  UPFs have many plus points, being relatively affordable, tasty, easy to prepare and convenient to fit into an adolescent lifestyle, but there may be a risk of assuming the higher consumption is a negative thing for health.

“As noted within their smaller analysis relating to physical activity, those with higher physical activity levels have higher UPF consumption, showing a potential connection with this health promoting behaviour and higher UPF consumption.  It would be interesting to see any connections with other nutrients, other markers of health or health behaviours and UPF consumption, to give a rounded picture on these relationships and the potential impacts of UPF consumption.

“To echo the widely noted criticism of the NOVA classification system, any research based on the NOVA UPF category must be interpreted with care, since there are a subset of UPFs that are less negative for health and serve helpful roles in the diet, especially in the adolescent diet, for example fortified unsweetened cereals and many dairy products.  However, this research does show some interesting associations and slight reductions in consumption of UPFs over the recent years, which would be interesting to explore in further detail.”

Dr Thanasis Tektonidis, Lecturer in Nutrition, Oxford Brookes University, said:

“The authors are very cautious in their discussion and throughout also in the media press that they talk about UPF and trends – not making any arbitrary speculation about health / disease.  In addition, while the study shows interesting associations with demographics and slight reductions in UPF consumption over recent years, it’s crucial to remember that these are associations, not causations.

“The cross-sectional nature of the data limits the ability to draw causal inferences.  Future research should focus on using longitudinal data to better understand the long-term health impact of UPF consumption.  Accounting for more sophisticated socioeconomic and lifestyle factors such as household food security, access to fresh foods, frequency of family meals vs eating out, could further help us understand the observed associations.”

Dr Carmen Piernas-Sanchez, Nutrition scientist, Nuffield Department of Population Health, University of Oxford, said:

“The study appears to be well-conducted, and the results are representative of the UK adolescent population.  The percentage of total daily energy intake from ultra-processed foods (UPF) is very high, despite the declines observed over recent survey years.  Similar figures have been reported in other countries, such as the US.  This study provides the latest estimates of UPF consumption in adolescents and offers some evidence of disparities across age, region, ethnicity, and socioeconomic status (SES) groups.  Future studies of this type should report the top food sources contributing the most to UPF consumption, which may further help inform policies aiming to improve dietary quality in the UK population.”

Dr Duane Mellor, Dietitian and Spokesperson for British Dietetic Association; and Honorary Academic Fellow at Aston University, said:

“This is an interesting analysis of food diaries collected as part of the UK National Diet and Nutrition Survey.  The authors suggest that 11-18 year olds in the North of England reported eating more calories from ultra processed foods than those in the rest of the country.  Additionally young people from more disadvantaged families ate more ultra processed foods, perhaps suggesting that access to healthier foods might be more challenging based on income and opportunity.  What is perhaps most interesting, is that the analysis suggested that over time calories from ultra processed foods seem to be declining.

“However, this finding needs to be treated with caution as the same young people do not report what they have eaten each year, as every year different people are asked to complete a food diary.  So, it is possible that very different people from similar backgrounds with very different dietary habits each year, so it is hard to draw conclusions when some years seem different to others – it could be purely down to chance.  The authors are also very clear that the classification of foods as ultra processed based on four day foods diaries is open to errors as the method is not designed to be used to estimate ultra-processed food intake and the NOVA classification is not designed to be applied to the UK diet, let alone different variants of the British diet.  This could mean a homemade pie which in the diary is stated as a cheese and onion pie – whilst perhaps not a healthy choice, if homemade would not meet the NOVA criteria to be criteria to be defined as a ultra-processed food, but without the detail of how it’s made this misclassification, as the authors admit, could be quite common.

“Finally, this paper only reports secular trends in food behaviour, there is no information about how this might impact the health of the young people involved in the study.  So, it is important not to assume or extrapolate what health effects occur without having that data and information.”

‘Ultra-processed food consumption in UK adolescents: distribution, trends, and sociodemographic correlates using the National Diet and Nutrition Survey 2008/09 to 2018/19’ by Yanaina Chavez-Ugalde et al. was published in European Journal of Nutrition at 02:20 UK time on Wednesday 17 July 2024.

DOI: 10.1007/s00394-024-03458-z

Declared interests

Dr Thanasis Tektonidis: “No conflict of interest”

Dr Aisling Daly: “Dr Daly has no conflicts of interest, and her research specialities are in adolescent nutrition, diet and eating habits.”

Dr Carmen Piernas-Sanchez: “No conflicts.”

Dr Duane Mellor: “I have discussed and been a consultant about the concept of UPF for EUFIC, APPGs (both unpaid as part of my previous academic role) and members of the food industry (including Mars and Danone as a paid independent consultant).”