PHI|Lab is working on, or has completed, a range of research projects on the social, environmental and system influences on health. Below describes our ongoing and recently completed work:
Projects led by PHI|Lab researchers
Projects led by PHI|Lab researchers
Restricting high fat, salt and sugar (HFSS) advertising on public transport networks: process and impact evaluation
Funder: National Institute of Health Research (2019-2021)
Marketing and branding is effective in encouraging the purchase and consumption of food and drink, but the impact of outdoor advertising specifically needs further research (PHE, 2018). Advertising may influence adult behaviour but also children’s food choices through pester power.
The Mayor of London is therefore implementing restrictions on the advertising of high fat, sugar and salt (HFSS) food and drink (as defined by the PHE Nutrient Profile Model) advertising across the Transport for London (TfL) estate. TfL advertising estate makes up approximately 40 per cent of London’s out of home advertising by revenue. This new policy came into force on February 25th 2019.
This project aims to undertake (i) an impact evaluation and (ii) a process and implementation evaluation of restrictions to HFSS advertising on: exposure to HFSS advertising, perceptions of HFSS foods and food purchasing in London.
This project is led by Professor Steven Cummins, in collaboration with Dr Laura Cornelsen and Dr Claire Thompson and alongside colleagues from LSHTM, Cambridge, Bristol & Teeside. Research Fellows for this project are Dr Vanessa Er and Dr Christelle Clary.
Asymmetry in consumer demand for foods and beverages in response to increasing and decreasing prices
Theoretical and empirical study of flexible price elasticities including reference price effects
Funder: Medical Research Council
This project used highly disaggregated product-level data to estimate a consumer demand incorporating reference price effects to allow flexible price response to increasing and decreasing prices. From this model we are able to estimate demand elasticities of increasing and decreasing food prices. Understanding asymmetry in consumer demand has direct implications for modelling the effectiveness of price-based health-related food policies, such as taxes or subsidies. Our findings suggest that asymmetry in price response exists and in general consumers respond stronger to price increases relative to price decreases but its magnitude depends on the level of aggregation. Our ongoing work analyses the implications on policy effectiveness in greater detail and also explores further explanations to asymmetric demand beyond reference price effects.
A working paper describing the adapted demand model is available here.
Biondi, B., Cornelsen, L., Mazzocchi, M., Smith, R.D. 2020. Between preferences and references: Asymmetric price elasticities and the simulation of fiscal policies. JEBO. 180, 108-128. https://www.sciencedirect.com/science/article/abs/pii/S0167268120303462?via%3Dihub
Cornelsen, L., Mazzocchi, M., Smith, R.D. 2019. Fat tax or thin subsidy? How price increases and decreases affect the energy and nutrient content of food and beverage purchases in Great Britain. Soc. Sci. Med. 230, 318. https://doi.org/10.1016/j.socscimed.2019.04.003
Framing and signalling effects of taxes on sugary drinks: a discrete choice experiment among households with children in Britain
Experimental study of demand for sugary drinks and how it is affected by fiscal policy
Funder: Medical Research Council
More than 20 countries have in the past 10 years implemented taxes on sugary drinks. Over time the motivation for doing this has become increasingly explicit in addressing the growing prevalence of obesity and associated NCD-s. In many settings taxes are also earmarked to other interventions tackling poor diets and obesity. This project measured if introducing the tax as a health related measure and signalling the tax amount with the price changes demand for these beverages beyond what would be expected of a simple price change of the same magnitude. We conducted a split design online Discrete Choice Experiment in September 2017 among 603 British households with children and who are regular consumers of sugary drinks.
We found suggestive evidence that a price increase leads to a larger reduction in the probability of choosing SSBs when it is signalled as a tax and framed as a health‐related and earmarked policy. Respondents who did not support a tax on SSBs, who were also more likely to choose SSBs in the first place, were on average more responsive to a price increase framed as an earmarked tax than those who supported the tax.
We also looked at the predictive validity of the DCE, to capture preferences for beverages, confirmed using actual purchase data from the same households.
Paper: Cornelsen, L., Quaife, M., Lagarde, M., Smith, RD. 2020. Framing and signalling effects of taxes on sugary drinks: A discrete choice experiment among households in Great Britain. Health Economics, 29(10), 1132-47.
Voluntary food industry actions in the UK and its impact on food and beverage purchases and consumption: a review
The role and responsibility of food industry in particular in helping to tackle unhealthy diets is recognized and action called for by public health experts as well as policy makers. Over time a number of voluntary steps have been, and will be taken by the industry that address diet-related ill-health. Some of these, are motivated from changing consumer preferences (e.g. greater demand for healthier foods) and others, due to changing policy environment explicitly targeting poor diets but remaining non-regulatory (e.g. voluntary reformulation or labeling programs). Among the actions, of course, some may have been due to factors external to diet and health (e.g. changing costs of ingredients or other production inputs). In this project we are currently carrying out a review to identify industry voluntary actions that have been communicated publicly in main British food industry journals (2007-2018), as at least partially, affecting dietary health; map the reasons behind implementing these actions and analyse the effectiveness of the most common/popular actions. This will be followed by empirical studies looking at the impact from these changes on purchase behavior.
The review is led by Dr Laura Cornelsen in collaboration with Soledad Cuevas (LSHTM) and Nishali Patel.
Out-of-home food and beverage expenditures in Britain 2015-2017
Study of large secondary data on socio-economic disparities of household expenditures of foods consumed outside homes
Funder: Medical Research Council
A growing body of literature focuses on the role of foods consumed out-of-home, particularly fast food and takeaways and its contribution to diets, and particularly to excess and discretionary energy or other nutrient intake. However, detailed data on out-of-home and on-the-go purchases is difficult to collect and is therefore scarce. In this project we use a novel dataset from Kantar Worldpanel from ~8,500 respondents in Britain who recorded their purchases for out-of-home consumption. The study explores the out-of-home food purchase allocations between different outlets and by food and beverage groups across socio-economic status.
Paper: Cornelsen, L., Berger, N., Cummins, S., Smith, R., 2019. Socio-economic patterning of expenditures on ‘out-of-home’food and non-alcoholic beverages by product and place of purchase in Britain. Soc. Sci. Med. https://doi.org/10.1016/j.socscimed.2019.112361
Recent trends in energy and nutrient content of take-home food and beverage purchases in Great Britain
Analysis of large secondary data on household food expenditures
Funder: Medical Research Council
In light of persistently high prevalence of obesity and rising cost of treating associated non-communicable diseases, the UK has been, in the recent years, developing a coherent obesity strategy including a range of policy initiatives aimed at improving diet, with particular focus on reducing sugar consumption. If these concurrent regulatory and voluntary policy initiatives, were successful, one would expect to observe at least small, positive changes in household food and energy purchasing behaviours. In this work we explore changes in trends in the nutrient content of take-home food and beverage purchases within this policy environment. We use Kantar Worldpanel data on take-home purchases from 2012-2017 to estimate changes in energy and nutrients purchased from healthier and less healthy food groups defined using the nutrient profiling model used by the UK Department of Health. Socio-economic differences are also investigated.
Paper: Berger, N., Cummins, S., Smith, R.D., Cornelsen, L., 2019. Recent trends in energy and nutrient content of take-home food and beverage purchases in Great Britain: an analysis of 225 million food and beverage purchases over 6 years. BMJ Nutr. Prev. Heal. bmjnph-2019-000036. https://doi.org/10.1136/bmjnph-2019-000036
Heterogeneous and long-term effects of social interventions on mortality and psychological health
The objective of this project is to assess the potential of education and income policies and interventions to reduce health disparities at different stages of the life course. The specific aims are: (1) to evaluate long-term and heterogeneous effects of randomized social interventions implemented at different stages of the life course on mortality and psychological health and (2) to investigate effect heterogeneity by underlying genetic risk using quasi-experimental approaches.
This work is led by Dr Emilie Courtin.
Understanding the health and wellbeing challenges of UK food poverty and food aid: a qualitative study
An ethnographic study of foodbanking and professionals working with food banks in London
Funder: The Wellcome Trust (2016-2019)
Food poverty is negatively associated with health. Therefore, local food aid provision is crucial to helping protect the health and wellbeing of vulnerable groups. At present, the politics and logistics of this provision are only partially understood and under-theorised. In London, one of the most expensive and equal cities in the world, food insecurity is intensifying. Long-term provision of food aid presents challenges for health maintenance and promotion that are frequently overshadowed by more immediate problems at the local level.
This ethnographic study used semi-structured interviews, observations and video diaries to explore experiences of food poverty, referral and food banks. Twenty London-based health care professionals, eight food bank volunteers and 14 food bank clients were interviewed. Observations were carried out at local authority food poverty working group meetings.
Lived experiences of food poverty are embedded in, and symptomatic of, the perpetual uncertainty associated with precarious incomes, insecure housing and limited agency over other external factors. Food poverty impacts upon health and wellbeing both directly – in terms of dietary health – and indirectly through contributing to the amplification and perpetuation of marginalisation.
Food banks start where the welfare safety-net stops, with health and social care professionals in the position of having facilitate this transition, Examining the processes through which this occurs is key to understanding the local mechanisms of state retreat and the subsequent increasing role of the third sector in shouldering the burden of social welfare provision.
This project is led by Dr Claire Thompson.
As part of this research theme we have organised two stakeholder seminars, reports of which are available on the PHI|Lab website. The first results paper from the project can be found here and an overview of the project here.
After two waves of London-based data collection we have worked with Preston Street Films to make an infographic outlining the practical challenges of long term foodbanking as they were explained to us by foodbank organisers – especially those working in independent food banks. This short piece is intended to provide an overview for those unfamiliar with the sector and the issue.
Universal credit and marginality in the smart city: scoping the health impacts of social policy transformation in London
A qualitative scoping study of the experiences and perceptions of key actors in the new Universal Credit (UC) system.
Funder: LSHTM / KCL joint small research grant (2018-2019)
Whilst initially widely supported, universal credit (UC) now elicits growing public concern over its negative impacts on health and social welfare, particularly among the most vulnerable, making it an emerging priority for research. UC has been framed both as a structural response to deprivation and marginalisation – in terms of its systematic obligation towards paid work and mimicry of a ‘monthly wage’ – and, conversely, as a mechanism of further marginalisation and social exclusion. UC rolls together six existing benefits into a single online-only system. Its stated aim is to foster individual financial autonomy by forcing claimants to manage their own money in a deliberate attempt to ‘improve’ financial ‘behaviour’. However, the combination of structural challenges, well-publicised administrative errors and overlapping vulnerabilities has meant that this scheme can cause more financial hardship. There is substantial scope for UC to shape the health and wellbeing of claimants, especially for vulnerable groups like the homeless and those accessing food banks.
This six-month qualitative study of the experiences and perceptions of key actors in the new UC system is addressing the following research question: how do those actors charged with implementing UC construct and categorise claimants, and how does this shape lived experiences of marginalisation for vulnerable urban UC claimants?
This London-based study consists of qualitative interviews with UC stakeholders: claimants; Local Authority and Third sector staff working with claimants working with UC. A stakeholder seminar will be held at the end of the study.
Soft Drinks Industry Levy (SDIL) Evaluation (led by University of Cambridge)
Funder: National Institute of Health Research (2017-2021)
On 16th March 2016 , the UK government announced a Soft Drinks Industry Levy (SDIL). This measure introduced two bands of the levy to be paid by the producers or importers of soft drinks which contain sugar. The rates of the levy were set at two bands – £0.18/L for total sugar content above 5g per 100ml; a higher band of £0.24/L for drinks with more than 8g per 100ml. The proceeds of the levy will be used to increase sports funding for schools. Companies were given a two year window to reformulate their products and reduce added sugar content before the SDIL came into force in April 2018. Researchers in PHI|Lab who are part of the SDIL evaluation team focus on the wider economic and societal impacts of the levy, including the effect on industry. To do this we use stock market data, corporation financial reports and government statistics on sector employment as well as data on spending across education and other economic indicators. In one of the analyses we apply an event study methodology to analyse the impacts of the SDIL announcements on the stock market values of UK soft drinks firms listed on the London Stock Exchange. We have looked at identifying the impacts of the SDIL on turnovers of soft drink manufacturing industries as well as food and beverage serving industries.
For further information can be found here.
The ENABLE London Study
Funder: National Institute of Health Research (2016-2018)
The ENABLE London study is a controlled longitudinal study investigating the impact on physical activity of urban design that encourages walking, cycling and use of outdoor space. A major aim of the study is to find ways to improve the design and planning of neighbourhoods to encourage active travel and wellbeing.
The project is a natural experiment which aims to establish whether physical activity and other health behaviours show sustained changes among individuals and families relocating to East Village (formerly the London 2012 Olympics Athletes’ Village) which has been developed using ‘active’ design principles, when compared with a control population living outside East Village. Professor Steven Cummins, Dr Daniel Lewis and Dr Christelle Clary lead the environmental exposure assessment element of this study.
Initial papers from this study can be found here.
Sustainable and Healthy Food Systems
Funder: The Wellcome Trust
Sustainable and Healthy Food Systems (SHEFS) program aims to provide policy makers with novel, interdisciplinary evidence to define future food systems policies that deliver nutritious and healthy foods in an environmentally sustainable and socially equitable manner.
Researchers in PHI|Lab focus on understanding changes in Indian diets. Indian diets have been shifting from being dominated by traditional staples to diets that are higher in processed foods. As processed foods tend to be high in fats, salt and sugar, an unintended health outcome has been an increase in the occurrence of obesity and other diet-related diseases. The prevalence of childhood and adolescent overweight in India reaches around 20% to 25% in urban areas. Meanwhile, the hunger situation of India remains serious, as indicated by the Global Hunger Index. This shift in dietary pattern has therefore complicated the nutritional challenges faced by the Indian policymakers. In light of its public health consequences, this project aims to understand the evolving consumption patterns of processed foods and beverages in India and to provide evidence for policymakers to make informed decision on future food and nutrition policies.
We use household purchase data to understand the demand for processed foods and beverages in India from 2013 to 2017. These data, previously unused in academic research, are collected from a large household panel in India who report product level data on their purchases of packaged and processed foods and beverages. A descriptive analysis was first conducted to illustrate recent trends in purchases of processed foods and beverages, the difference in purchase patterns across Indian states and the nutritional implication of these trends and patterns. We also plan to use this dataset to identify causes for rapid changes in patterns and linking these to policy and other changes in environment, for example, the Maggi noodles scandal in 2015 and the recent tax reform in India.
Further information on SHEFS can be found here.
The MOTIVATE project: modelling normative change in active travel
Funder: LSHTM / KCL seed funding (2018-2020)
There is growing commitment globally to rebalancing the travel system, so that more journeys are made using more active modes, particularly walking and cycling. Walking and cycling are good for people’s physical and mental health, and reduced dependency on private cars mitigates noise and air pollution, reduces risk of road traffic injury and prevents cardiovascular disease and obesity.
A structural barrier to active travel is the design of the urban built environment, where roads can act as physical barriers to pedestrian movement and interaction. Governments are investing substantial resources to remove structural barriers to active travel. One example is the Transport for London/Greater London Authority Mini-Holland initiative, a programme aimed at reducing car use and increasing walking and cycling through changes such as new cycle lanes and coherent walking and cycling routes, new and upgraded pedestrian crossings that prioritise walking over cars, upgraded junctions to improve traffic flow, new and improved public spaces, etc.
Complex interventions such as this are difficult and expensive to evaluate. Often, evaluations are geared towards establishing whether the intervention worked based on aggregate measures of usage. Determining why an intervention worked is much more challenging and it can be difficult to unpack the contribution of different pieces to the success or failure of the whole. Also often left unspoken is the role of individual agency and the underlying social norms of travel behaviour.
MOTIVATE is an exploratory study of how differing social norms surrounding mobility may impact of the effectiveness of structural interventions to promote active travel, using agent-based modelling. It is led by Dr Simon Miles at the Centre for Urban Science & Progress at King’s College London (KCL) and Professor Steven Cummins. It also involves Dr Jon Reades (KCL), Dr Daniel Lewis and Robert Greener.
In this project we use agent-based models to simulate the effects of differing social norms on the effectiveness of active mobility interventions. Agent-based simulation is a bottom-up modelling process in which individuals, households or other autonomous entities are imbued with simple behavioural rules that define how they act in an environment and interact with one another. These rules derive from a conceptual understanding of a system of interest, augmenting analyses of observational data based on aggregate patterns of mobility to simulating the impact of individual preferences.
The MOTIVATE project explores two linked research questions: what social norms of travel behaviour minimise or maximise the effectiveness of interventions on active travel, and can we simulate, using agent-based models, the potential impact of social norm interventions on the effectiveness of interventions?
Models and code for this project are available at GitHub and papers are currently in development: https://github.com/ragreener1/Motivate/releases/tag/0.0.5
Modelling the demand for sugary drinks, sweet snacks and potential of fiscal policies
In collaboration with Behaviour and Health Research Unit we analysed consumer demand responsiveness to increases in price of sugary drinks, alcohol and sweet snacks to study the effects of increasing prices on the demand for these products but also the cross-price effects which show if increasing the price of one product (such as sugary drinks) changes the demand for other products (such as alcohol or sweet snacks).
In a first study we looked at how increasing the price of non-alcoholic drinks could influence purchases of alcoholic drinks, such as beer, wine and cider, in supermarkets. We found that increasing the price of sugary drinks could increase purchases of lager, while increases in the price of diet drinks could increase purchases of beer, cider and wines.
In a second study we looked at how increasing the price of snack foods might compare in impact. We found that a 10% increase in the price of sweet snacks could lead to a similar reduction in consumer demand as the same price increase for sugar-sweetened drinks. However, such a price increase is estimated to have knock-on effects that may further reduce purchases of sugar-sweetened drinks and other snacks. Furthermore, as sweet snacks provide twice as much sugar in the diet as sugar-sweetened drinks, the overall reduction on sugar intake could be even greater than that observed with price increases for sugar-sweetened drinks.
In a third study we looked at how much prevalence of obesity could change if sweet snacks were subject to a 20% price increase through a measure such as a tax across income and BMI groups. We found that this could reduce prevalence of obesity on average by 2.7 percentage points after one year and we found largest effects among low-income households classified as obese and smallest effects among high-income households classified as not overweight.