Skip to content

Bethany Parkes

PhD student

Healthy Places, Healthy Planet

University of Exeter

Project title

Are healthy diets really more expensive than unhealthy diets? Understanding drivers of choice between healthy and unhealthy food and drinks. 

Project summary

There is a popular perception, based on some evidence, that healthy food costs more than unhealthy food, and since price is a major determinant of demand, that addressing this price imbalance will rebalance consumption of healthy versus unhealthy foods. This has been the rationale behind the high-profile rise of various ‘fat tax’ and ‘sugar tax’ initiatives in recent years. However, when the cost of the whole diet is considered, evidence from Australia found that healthy diets could be 15% less expensive than current (unhealthy) diets. There is concern, also, that taxing specific products does not necessarily lead to overall healthier dietary patterns. These observations cast doubt on the relative importance of price as the critical driver of food choice in the context of the whole diet, and this remains a significant gap in evidence underlying related health and fiscal policies. The assumption from which this study departs is that demand is affected not only by price but also by consumers’ knowledge, attitudes and behaviours that are in close inter-play with socio-demographic characteristics, as well as by food availability, access, marketing, food preferences and values, ‘taste’, food literacy, ability to prepare and store foods, perceptions of ‘healthiness’ etc. The aim of this project is to add to the evidence base around food and diet costs and drivers of food choice. Specifically to: 1. Determine the cost of healthy vs unhealthy diets in the UK 2. Investigate the main price and non-price drivers for healthy and unhealthy food demand 3. Analyse those drivers attending to socioeconomic contexts, including the study of the heterogeneity between food markets and socioeconomic and demographic structures 4. Develop mechanisms to turn this knowledge into policies and practices that promote healthier food consumption and thus to promote health, i.e. to generate impact from research

Bethany's Q&A

  • What has been your career journey so far?

    I began working in local authority public health at the start of 2021 while working towards an Msc in Health Psychology. Working in public health taught me a lot about health inequalities in the population, and how wider determinants of health can contribute to these. The roles I have held in the local authority have led me to appreciate the importance of building a strong evidence-base for all that we do in public health.

  • Why did you choose to do a PhD in public health research?

    One of the reasons that I choose to do a public health research PhD is that I wanted to build my independent research skills. A PhD provides many training opportunities, chances to develop myself as an early career researcher and is a great way to expand my skill set. Secondly, I feel very strongly about the importance of everyone having equal access to a healthy and nutritious diet and I felt I could contribute to this area of work.

  • What is your research focused on?

    My PhD is focused on food affordability, in particular understanding how affordable a healthy diet is in comparison to an unhealthy diet. In addition, I am looking into the drivers of food choice, and how price/cost of food sits among other drivers of food choice (e.g., habit, income, education etc.).

  • Why is it important?

    This topic is very important, as it will inform both policy and intervention development for use in public health. We know that having a healthy diet is an important part of staying healthy, but currently not everyone is eating a diet in line with the Eatwell recommendations. Understanding more about what drives healthy and unhealthy eating, and the extent to which the affordability of food is a key driver are important steps to supporting initiatives which may improve the diet of the population.

  • What do you like about being a part of the NIHR School for Public Health Research?

    I love being able to connect with others through the ResNet. This is a great way to meet not only other PhD students, but other early career researchers.

  • What skills have you learnt and/or are hoping to learn as part of your PhD?

    I am hoping to learn key research skills such as writing academically for journal publications and how to communicate findings to varied audiences.

  • What do you hope to do after completing your PhD?

    I hope to continue working in public health and continue with my work in the area of nutrition and healthy diets. There are lots of possibilities for further research which I would like to explore as I continue through the PhD.

We use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it.

OK Privacy Policy