Mental Models of Obesity

Previously I suggested that in order for health behaviour change to be successful, we not only need to alter the decisions we make, but that we also need to modify the habits, routines, interpretations, and attributions that we base these decisions on. In other words, our mental models about obesity can act as a barrier to success in weight management, as based on Sterman’s description of double loop learning (1). So, just what are our most deeply held beliefs about obesity and weight management?

A 2001 study by Ogden et. al. addresses this very question (2). They administered questionnaires to both patients and general practitioners in order to gain insight into how each group viewed: a) the causes of obesity, b) the consequences of obesity, and c) treatment options. Their results highlight some differences as well as some similarities between the groups’ perspectives (Figure 1), which may have implications for the clinical management of obesity.

General practitioners were more likely to attribute the cause of weight gain to patient behaviours such as overeating, lack of exercise and poor diet. Although patients also attributed weight gain to individual behaviour, they were more likely to identify other factors as significant contributors, including slow metabolism, gland or hormone problems, and stress, as compared to the physicians. The two groups also differed in what they perceived to be the most important consequence of obesity. While physicians ranked development of diabetes as the top concern, patients were more concerned with difficulty getting work. Perspectives on treatment methods were similar for both groups. Physicians however again placed the responsibility on the patients, while patients identified a need for help from their general practitioner or other health care providers.

Figure 1: Mental Models of Obesity (adapted from Ogden et. al.)

The study is limited by the use of a survey to determine the factors that subjects identify as shaping their beliefs about obesity, its causes and consequences and options for treatment. The survey format used only allowed those factors initially identified by the researchers and included in the survey to be identified by the study participant. It is possible that other factors may also help shape mental models of obesity.

As Ogden et al discuss, these discrepancies in mental models about obesity have implications for the communication between a physician and a patient, as well as for the success of interventions (2). Do these differences contribute to the poor success rates of primary care intervention for obesity? And regardless of the effect on communication between physicians and patients, do these perceptions about obesity themselves create barriers to learning and behaviour change?

The next questions to explore include identifying the existing feedback loops that shape these mental models and looking for ways in which we can modify them or add new feedback loops.

1. Sterman, J. D. (1994). Learning in and about complex systems. System Dynamics Review, 10(2-3), 291-330. doi:10.1002/sdr.4260100214

2. Ogden J, Bandara I, Cohen H, Farmer D, Hardie J, Minas H, Moore J, Qureshi S, Walter F, & Whitehead MA (2001). General practitioners’ and patients’ models of obesity: whose problem is it? Patient education and counseling, 44 (3), 227-33 PMID: 11553423