**6. Conclusions and future directions**

hood obesity might; see [43]), and simply describing obesity as a disease can make weight gain

Recent research suggests that reading personal testimonials about successful weight loss may help people construct a more positive mental model of obesity [41, 43–46]. Stories about individuals struggling (and succeeding or failing) to lose weight are ubiquitous, engaging, and provide a structured framework for thinking about the causes of and solutions to obesity [16, 17, 47]. Consider, for example, the popular reality television program "The Biggest Loser," in which morbidly obese contestants compete, through hard work and dedication, to lose the most weight over the course of the season. Although the show has been criticized for a variety of reasons—for promoting an unhealthy and unrealistic approach to weight loss [48] and because contestants have been found to regain lost weight after the show ends [18]—there is some evidence that it increases viewers' sense that they have control over their weight [49]. This suggests that exposing people to personal testimonials in which a protagonist succeeds at achieving a weight-loss goal—through healthy and realistic diet and exercise—may foster an incremental theory of the condition, making them more optimistic about obesity treatment

In other words, it may be more effective to adopt a "bottom-up," rather than "top-down," approach to changing the way people think about obesity. Describing the underlying causes and consequences of obesity at a high level—by classifying the condition as the product of one's "environment" or the result of an underlying "disease"—represents a "top-down" strategy: seeking to change the stigma associated with obesity and increase support for public policy interventions by situating the condition in a particular causal framework (e.g., [51–53]). The drawback of this approach, as noted in the previous section, is that the candidate causal structures seem to encourage some inferences that are at odds with the goals of public health

An alternative "bottom-up" approach would describe specific instances of people successfully losing weight, which could provide the foundation for people to induce the "right" lay theory of obesity: one that acknowledges causes of obesity that are within *and* outside a person's control, which motivates individuals to maintain a healthy lifestyle *and* promotes support for interventions that would address the social and environmental context that has given rise to

One specific feature of personal testimonials is that they provide the reader an opportunity to feel empathy for an individual struggling to lose weight [54]. In this context, empathy reflects the process of identifying with someone else's struggle with obesity—taking their perspective and sympathizing with their condition [55]. A natural byproduct of such a feeling is an increased awareness of factors that cause obesity that are outside a person's control [41, 42, 56]. Thus, exposing people to personal narratives that describe successful weight loss may be particularly effective tools for public health officials. Such testimonials may lead people to support policy interventions that would address the social and environmental contexts that have given rise to obesity without completely mitigating the sense of personal responsibility

feel inevitable and weight loss feel impossible.

30 Adiposity - Epidemiology and Treatment Modalities

in general [50].

officials.

the current public health crisis.

that is needed to maintain healthy habits.

In recent years, the general public has come to agree with public health officials who view obesity as a critical global concern. A 2012 survey found that 81% of the American public believes that obesity is an "extremely" or "very serious" problem [1]. However, recent research has found important differences between scientific and lay theories of obesity. While scientists and public health officials recognize an array of social, psychological, and physiological factors that contribute to obesity, non-experts often view the issue through a less sophisticated lens. In this chapter, we have described a variety of lay theories of obesity—focusing on trait-level beliefs, on causal models of obesity, and on personal narratives—that have important implications for the public health crisis.

At the trait level, some people think about psychological and physical attributes as relatively fixed, whereas others think of such attributes as relatively malleable. Empirical research has found that it is important for people to think of weight as malleable in order for obesity-related treatments to work. Talking about obesity as a disease, a strategy that public health officials have adopted in recent years to mitigate the stigma associated with being overweight, may, unfortunately, encourage people to think of weight as being caused by underlying physiological factors that are outside of one's control. Instead, focusing on the individual level—by describing a person who successfully loses weight through diet and exercise—may represent a more effective strategy for public health communications related to obesity. Personal narratives elicit more empathy than causal narratives. As a result, they may be able to mitigate the widespread stigma against obesity and increase support for societal-level policy interventions designed to address causes of weight gain that are outside a person's control, while at the same time encouraging people to adopt an incremental trait theory of the condition.

There are a number of opportunities for future research based on this perspective. One goal of future work should be to consider how personal narratives for obesity affect causal and trait theories of the condition in more detail. For instance, how does a personal narrative about successful weight loss affect people who think of obesity as a disease? What is the most effective way to characterize a causal model of obesity that balances the complex suite of factors that have contributed to the rise of obesity? Another goal will be to figure out how to integrate theoretical and experimental research into scalable public health-messaging campaigns, putting what we now understand about lay theories of obesity—and how to change them into practice.
