Common Sense Models of Obesity: a Qualitative Investigation of Illness Representations

The Common Sense Model provides a framework to understand health beliefs and behaviors. It includes illness representations comprised of five domains (identity, cause, consequences, timeline, and control/cure). While widely used, it is rarely applied to obesity, yet could explain self-management decisions and inform treatments. This study answered the question, what are patients' illness representations of obesity?; and examined the Common Sense Model's utility in the context of obesity.

Twenty-four participants with obesity completed semi-structured phone interviews (12 women, 12 men). Directed content analysis of transcripts/notes was used to understand obesity illness representations across the five illness domains. Potential differences by gender and race/ethnicity were assessed.

Participants did not use clinical terms to discuss weight. Participants' experiences across domains were interconnected. Most described interacting life systems as causing weight problems and used negative consequences of obesity to identify it as a health threat. The control/cure of obesity was discussed within every domain. Participants focused on health and appearance consequences (the former most salient to older, the latter most salient to younger adults). Weight-related timelines were generally chronic. Women more often described negative illness representations and episodic causes (e.g., pregnancy). No patterns were identified by race/ethnicity.

The Common Sense Model is useful in the context of obesity. Obesity illness representations highlighted complex causes and consequences of obesity and its management. To improve weight-related care, researchers and clinicians should focus on these beliefs in relation to preferred labels for obesity, obesity's most salient consequences, and ways of monitoring change.