Messages that describe obesity as a disease may undermine healthy behaviors and beliefs among obese individuals, according to a new study published in Psychological Science, a journal of the Association for Psychological Science.

The findings show that obese individuals exposed to such messages placed less importance on health-focused dieting and reported less concern about weight. These beliefs, in turn, predicted unhealthier food choices.

Psychological scientists Crystal Hoyt and Jeni Burnette of the University of Richmond and Lisa Auster-Gussman of the University of Minnesota were interested in exploring the effects of health and diet messaging after the American Medical Association (AMA) declared obesity a disease in June 2013.

"Considering that obesity is a crucial public-health issue, a more nuanced understanding of the impact of an 'obesity is a disease' message has significant implications for patient-level and policy-level outcomes," says Hoyt. "Experts have been debating the merits of, and problems with, the AMA policy - we wanted to contribute to the conversation by bringing data rather than speculation and by focusing on the psychological repercussions."

Hoyt and colleagues hypothesized that labeling obesity as a disease could encourage the belief that weight is unchangeable and make attempts at weight management seem pointless, especially among obese individuals - the very people that the public-health messages are targeting.

The researchers recruited over 700 participants to take part in an online survey across three different studies. Participants read an article related to health and weight and then answered various questions. Importantly, some participants read an article that described obesity as a disease, some read a standard public-health message about weight, and others read an article specifically stating that obesity is not a disease.

Height and weight data were used to calculate participants' body mass index and to classify participants as "average weight" or "obese," in line with World Health Organization guidelines.

Results showed that the particular message obese participants read had a clear impact on their attitudes toward health, diet, and weight.

Specifically, obese participants who read the "obesity is a disease" article placed less importance on health-focused dieting and reported less concern for weight relative to obese participants who read the other two articles. They also chose higher-calorie options when asked to pick a sandwich from a provided menu.

Interestingly, these participants reported greater body satisfaction, which, in turn, also predicted higher-calorie food choices.

"Together, these findings suggest that the messages individuals hear about the nature of obesity have self-regulatory consequences," says Hoyt.

The researchers point out that there may be benefits to the disease-focused message, such as promoting greater acceptance of diverse body sizes and reducing stigma, which may help obese individuals engage with health- and weight-related goals.

The new findings indicate, however, that there may be some hidden costs to the "obesity is a disease" message, including less motivation to eat healthy.

Hoyt and colleagues caution that more research is needed to gain a clearer understanding of both the costs and benefits of such health-related messaging before the findings can be put into practice.

"In our ongoing work, we hope to gain a greater understanding of how the 'obesity is a disease' message influences beliefs about the controllability of weight," says Hoyt. "In addition, we are also interested in investigating the role of this message in reducing stigma against the obese."

The researchers hope that their work "sparks further discussion and inquiry by researchers and practitioners alike."