Achieving successful behaviour change

30 November 2016

Talk by Dr Carmen E. Lefevre, UCL, UK.

Changing human behaviour is at the heart of solving global problems central to human well-being, social cohesion and environmental sustainability. For example, preventing obesity, air pollution and waste of environmental resources and improving cyber security and economic stability all require behaviour change at individual, organisational and population levels. Obesity in particular is one of the main health risk factors in countries such as the UK, where 26% of adults and 16% of children are obese, rates almost double those of 25 years ago. At the same time, purchases of fruits and vegetables have fallen dramatically in recent years, making it clear that behaviour change is urgently needed.

Theories of behaviour change afford an insight into how it may be possible to achieve lasting change for behaviours surrounding a healthy and balanced diet. For example, a well-known method of behaviour, the COM-B model suggests that for any behaviour to occur, the person enacting it needs to have the psychological and physical capability to enact the behaviour, the physical and social opportunity to enact it, and the automatic and reflective motivation to perform the behaviour in question more than any competing behaviour at a given time.1 Accordingly, for an intervention to successfully change behaviour, one first needs to understand clearly and precisely why a given behaviour is currently not performed or performed sub-optimally. For example, in the context of a healthy diet, it quickly becomes apparent that a different approach to behaviour change is required if the reason for a person’s poor diet is that this person does not know how to prepare a healthy meal (psychological capability) compared to if the same person is unmotivated to buy healthy over unhealthy food options. To date, the majority of communication campaigns aimed at changing eating behaviour have either had an educational focus (i.e. why you should eat well) or used ‘fear appeals’ (i.e. imagery and text evoking negative emotions to encourage behaviour change). However, these campaigns are not based on a systematic behavioural analysis and may therefore be less effective.

The approach to behaviour change at University College London (UCL) consists of five steps:

  1. First, the target behaviour needs to be selected and clearly specified. For example, should this behaviour be the purchasing of healthy foods, the preparation of healthy meals, or the consumption of food? While these behaviours are clearly related, they each have their own driving forces.
  2. The second step involves a behavioural diagnosis, an analysis of barriers and facilitators of the target behaviour, in terms of capability, opportunity, and motivation. For example, why don’t people buy healthy food? Is it too expensive, is it not on offer, or are people not aware of its healthiness?
  3. Next, in the third step, the behaviour change wheel is used to identify the most suitable intervention function to target the barriers identified in step two. For example, if the main barrier to the purchasing of healthy food is a lack of understanding that it’s healthy, then an educational campaign is likely most effective.
  4. Once the most appropriate intervention function is selected, the intervention designers need to choose the precise behaviour change techniques and delivery channel (e.g. print media, face-to-face, app) for the intervention.
  5. Finally, the intervention can be delivered and, in the fifth step, needs to be evaluated for its effectiveness and, if necessary, refined to improve effectiveness further.

Evidence to date suggests that interventions developed following a theory-driven approach, like the one outlined above, are more successful in changing behaviour than those that were not. Given the crucial need for achieving successful behaviour change soon, in order to reduce the behaviourally induced disease burden on society, these approaches, while perhaps seemingly overly complex provide the best chance for achieving what we need to achieve.


Michie, et al. (2011). The behaviour change wheel: a new method for characterising and designing behaviour change interventions. Implementation Science 6:42