Jason C G Halford   BSc PhD C.Psychol. AFBPS

Jason C G Halford BSc PhD C.Psychol. AFBPS


I studied psychology at the University of Leeds gaining my degree in 1991, and my PhD in 1995, and worked as a researcher until 1996 when I took up a position in the Department of Nutrition at Penn State University. 

I joined the Psychology Department at the University of Central Lancashire (UCLAN) in 1997 as a lecturer in Health and Neuroscience, and the School of Psychology, University of Liverpool in 1999 as a lecturer in Appetite and Obesity. 

I spent 21 years in Liverpool with a working sabbatical at the Obesity Research Center, Columbia University, St Luke’s Roosevelt Hospital, New York in 2006.

In 2010 I became head of Experimental Psychology at the University of Liverpool, and in 2013 I became head of Psychological Sciences, and Deputy Head of the Institute of Psychology, Health and Society,  I received my Chair at the University of Liverpool in 2011.

In 2015 I was appointed theme lead (Behaviour, Consumption and Health) for the N8 Agrifood representing the Northern Russell Group members. 

I am a past Chair of the UK Association for the Study of Obesity (ASO) and current Treasurer of the European Association for the Study of Obesity (EASO).  I am also the EASO President Elect. I am also a board member of the ECPO – European Coalition for People Living with Obesity.

ASO UK – https://www.aso.org.uk/ 

EASO – https://easo.org/

ECPO – https://eurobesity.org/ 



As an expert in mechanisms underpinning appetite regulation, eating behavior and energy intake, I work with industry in two broad areas, developing health foods and beverages, and developing and evaluating novel approaches for weight management. More recently some work has also focused on Health Psychology. 

  • I do not work with the food industry in the areas of policy and public health. 
  • I do not receive personal payment, and all income goes to the University of Leeds (and previously to the University of Liverpool) and this is used to support other researchers and academics (the companies do pay for my travel and accommodation when working with them).   
  • These associations and potential conflicts of interest are declared in relevant publications and presentations.

I am involved in two significant industry funded projects.



ACTION-IO and ACTION-Teens are international studies examining the perceptions, actions, behaviours, and other barriers to accessing obesity management for adults and adolescents living with obesity.  These studies are funded by Novo Nordisk. This is declared in study publications and presentations of the data (LINK).  My work with the company, past and present, is registered in the public domain Novo Nordisk and can be found here via the Association of British Pharmaceutical Industry - Disclosures UK sire (https://www.abpi.org.uk/reputation/disclosure-uk ).

Key ACTION papers






I am also Co-Co-Principal Investigator on the SWITCH trial, a 2-year study in the impact of low-calorie sweetener use, in weight management.  The trail is funded by the American Beverage Association.  This is declared on respective websites, via the trial registration (ClinicalTrials.gov links below) and on our published methodology paper.  It is also declared in all publications and presentations of the findings.

Key SWITCH links and papers

https://classic.clinicaltrials.gov/ct2/show/NCT02591134?term=SWITCH+and+Liverpool&draw=2&rank=1 (old ClinicalTrials.gov site) or https://www.clinicaltrials.gov/study/NCT02591134?locStr=Liverpool,%20UK&country=United%20Kingdom&state=England&city=Liverpool&distance=50&term=switch&rank=1 (new ClinicalTrials.gov site)




Participant data are not publicly available but can be requested from the corresponding author after study completion. Requests should be reasonable and accompanied with research proposals that have received appropriate ethical approval. Data will be made available in an anonymized format in compliance with applicable privacy and data protection laws.





  • Head of School

Research interests

A psychologist working in Obesity Practice and Policy. My focus is on appetite and eating behaviour and weight management interventions targeting this (behavioral, nutritional, pharmaceutical and surgical - traditional or digital). Conducted mechanisitic studies and weight management interventions focusing on approaches such as meal replacements, dietary fibre and protein supplementation to boost satiety (SATIN consortium), healthy snacking, and sugar replacement (current projects include the SWITCH trial and the SWEET consortium). Worked with the pharmaceutical industry on potential antiobesity therapies and preventing drug induced weight gain. Also studied the prescription of commercial weight management in primary care (WRAP)

Interests also in policy around food inequalities in food security in families, unhealthy food marketing to children, food labelling, and increasing access to obesity services and support. Extensive work on reducing children’s exposure to marketing of unhealthy foods and beverages through broadcast media, online and through social media influencers, which has lead to collaborations with Policy makers and NGOs including WHO.

Work extensively with stakeholders, including societies, NGOs, policy makers, industry and advocacy groups to promote healthier foods and develop more effective approaches to weight management.  Worked on consumer behaviour and health as theme lead in N8 Agrifood (2014-19). Our current project on sustainable food systems is iKnowFood.

Broad interests in the psychology of obesity, including links between mental and physical health, stress and coping, stigmatization and the experience of living with obesity.  Very much enjoy working with the patient community who have had an incredible impact on my research and teaching over the last few years.

Trial and Study Sites








  • PhD - University of Leeds
  • BSc (Hons) Psychology, University of Leeds
  • C.Psychol. (Health)

Professional memberships

  • British Psychological Society (Associate Fellow)

Student education

First and second year tutor

Contributor level one module

Contributor level two module

<h4>Postgraduate research opportunities</h4> <p>We welcome enquiries from motivated and qualified applicants from all around the world who are interested in PhD study. Our <a href="https://phd.leeds.ac.uk">research opportunities</a> allow you to search for projects and scholarships.</p>