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Psychological perspectives on obesity: policy, practice and research priorities

07 May 2020 | by Guest

Dr Angel Chater is a Reader in Health Psychology and Behaviour Change at the University of Bedfordshire and an expert in behaviour change related to obesity. Her career has spanned research, training, policy and practice as a health psychologist to specialist obesity services at the Luton and Dunstable Hospital.

“Obesity is not a ‘choice’”.

“Obesity is not simply down to a lack of willpower.”

These two sentences featured in the opening of our report and captured the attention of the media across the globe, reported in over 300 outputs, with 30,000 impressions on Twitter.

Our key overarching recommendation was clear - include psychology in the prevention and treatment of obesity (Perriard-Abdoh, Chadwick, Chater, Chisolm, Doyle, Gillison, Greaves, Liardet, Llewellyn, McKenna, Moffat, Newson, Reid, Scott, Shearer, Singh & Snowden-Carr, 2019)

Our recommendations (Perriard-Abdoh, et al., 2019) called for psychologically informed:

  1. Communications (including language and images)
  2. Policies
  3. Standards and guidelines
  4. Training and supervision
  5. Weight management services

It was surprising that this appeared to be novel to some news outlets (“Psychologists advise new approach to dealing with obesity”). Is it really that novel to try to understand what influences behaviour and health? Moreover, is ensuring that services are appropriate for those who use them, really ground-breaking? And is treating people with dignity actually new?

As psychologists, these considerations and approaches may be routine. However, these reactions highlight the importance of translating our recommendations into useable guidelines, to assure dignity for those living with obesity, to reduce weight-related stigma, and to ensure services are fit for those who use them and that those delivering interventions are supported with appropriate, psychologically informed policies, guidelines and training.

Obesity is routinely categorised by a body mass index of above 30 (kg/m2). Unfortunately, many people still believe that obesity is due to lack of willpower and is therefore a negative personal characteristic with equally negative stereotypes.

Whether conscious or unconscious, this approach of blaming the individual rather than addressing the underlying causes is harmful (Himmelstein, Puhl & Quinn, 2018) and the shame this often creates is not a motivator for behaviour change, as some argue.

Instead, this weight stigma perpetuates a negative cycle involving shame, unhelpful behaviours and weight gain, and can prevent people from leaving their home or attending weight management services for fear of abuse and ridicule (Husky, Mazure, Ruffault, Flahault & Kovess-Masfety, 2018).

Unfortunately, many health care professionals demonstrate biases that support weight stigma (Tomiyama, Finch, Belsky, Buss, Finley, Schwartz & Daubenmier, 2015), and people living with severe obesity, (a BMI of over 50), face further stigma as many services are unable to accommodate their needs in terms of appropriate equipment, furniture, etc.

It is essential going forward that we treat people with dignity, not define them by their condition (e.g. obese people) and avoid weight stigma.

Behaviour change is central to the prevention, management and treatment of obesity (Perriard-Abdoh, et al., 2019). But it is important to point out that obesity is not a behaviour. It cannot be changed overnight, and it is not possible to directly influence obesity unless an individual undergoes surgery to remove excess skin that may reduce a small percentage of weight.

Instead, we need to focus on the behaviours that are related to weight gain, weight loss and weight (loss) maintenance, particularly around nutrition, eating, and physical activity, and factors that may influence these.

Individuals living with obesity, did not reach that weight status overnight. They were likely influenced by a multitude of bio-psycho-social factors, including genetics, thoughts, feelings and interactions with their physical and social environment, over a prolonged period of time.

Drawing from a bio-psycho-social model (Engel, 1977) psychologists work with people living with obesity to understand how these factors interact to influence the behaviours that contribute to, or maintain, obesity.

Our report calls for psychological approaches and evidence to be used across the system, from individual intervention to the collective response to obesity, and national guidelines, such as those by NICE (2014) and SIGN (2010) already recommend that all weight management interventions include a psychological component.

A psychologically-informed nation can help to understand attitudes and unconscious bias, tackling stigma and consequential shame, while theoretical approaches can support the development of evidence-based interventions and best practice guidance when designing services that include appropriate psychological support.

Behaviour (change) is unlikely to occur if people do not have the Capability to enact the behaviour, Opportunity to enable the behaviour, or the Motivation to perform the behaviour. These factors form the COM-B model (Michie, Van Stralen & West, 2011) that sits at the hub of the behaviour change wheel (Michie, Atkins & West, 2014).

Frameworks based on the latest theories (such as COM-B) are already available for policy makers designing interventions, and these approaches have been highlighted in Public Health England’s ‘Improving People’s Health’ strategy.

Alongside the need to understand and intervene with behaviour, is a need to ensure that professionals working in this area are equipped with appropriate skills to support behaviour change (PHE, 2018; Royal College of Physicians, 2013).

When self-management and community interventions have proven unsuccessful, psychological input is needed to support higher tiered interventions. For example, psychologists can help establish behaviours around taking medication (Hollywood & Ogden, 2016) and adhering to advice when undergoing surgery.

Psychologists in weight management services play an additional role in assessing and addressing mental health difficulties, and it is important to have a strong connection between weight management and mental health services so that referrals are seamless and that staff are aware of how mental health and obesity are connected (generally this element of the psychologist’s role goes unacknowledged and is insufficiently resourced).

In sum, the need to consider psychology in the prevention and treatment of obesity is clear, and the BPS (2019) ‘Psychological Perspectives on Obesity’ report highlights some clear recommendations, presented below.

Read the full Psychological Perspectives on Obesity Report.


  • Engel, G. L. (1977). The need for a new medical model: A challenge for biomedicine. Science, 196, 129-135.
  • Himmelstein, M. S., Puhl, R. M., & Quinn, D. M. (2018). Weight stigma and health: The mediating role of coping responses. Health Psychology, 37(2), 139.
  • Hollywood, A. & Ogden, J. (2016). Failing to lose weight whilst taking orlistat: A qualitative study of patients at 18 months follow up. Journal of Health Psychology, 21(5), 590-598.
  • Husky, M. M., Mazure, C. M., Ruffault, A., Flahault, C. & Kovess-Masfety, V. (2018). Differential associations between excess body weight and psychiatric disorders in men and women. Journal of Women’s Health, 27(2), 183–190.
  • Michie, S., Van Stralen, M. M. & West, R. (2011). The behaviour change wheel: a new method for characterising and designing behaviour change interventions. Implementation Science, 6(1), 42.
  • National Institute for Clinical Excellence (2014). Obesity: Identification, assessment and management. CG189, Point 1.4.5. London: NICE.
  • Perriard-Abdoh, S., Chadwick, P., Chater, A., Chisolm, A., Doyle, J. Gillison, F., Greaves, C., Liardet, J., Llewellyn, C., McKenna, I., Moffat, H., Newson, L., Reid, M., Scott, K., Shearer, R., Singh, S. & Snowden-Carr, V. (2019). Psychological perspectives on obesity: Addressing policy, practice and research priorities. London: British Psychological Society.
  • Public Health England (2018). Improving people’s health: Applying behavioural and social sciences to improve population health and wellbeing in England. For more information see the online ‘Community of Practice’ hosted by the Behavioural Science and Public Health Network. http://www.bsphn.org.uk/
  • Royal College of Physicians (2013). Action on obesity: Comprehensive care for all. Report of a working party. London: RCP.
  • Scottish Intercollegiate Guidelines Network (2010). Management of Obesity: A National Guideline, 115. Edinburgh: SIGN.
  • Tomiyama, A. J., Finch, L. E., Belsky, A. C. I., Buss, J., Finley, C., Schwartz, M. B., & Daubenmier, J. (2015). Weight bias in 2001 versus 2013: contradictory attitudes among obesity researchers and health professionals. Obesity, 23(1), 46-53.


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