There are efforts to label obesity as a mental illness and a physical addiction. While that's good for psychologists who want get eating therapy paid by insurance claims, it may undermine healthy behaviors, according to a paper in Psychological Science.

Calling obesity an illness or a disease or a genetic issue makes it exculpatory, they note. Obese people already have poor impulse control and the new findings show that obese individuals exposed to 'it's a disease' messages placed less importance on health-focused dieting and reported less concern about weight. These beliefs, in turn, predicted unhealthier food choices.

The American Medical Association (AMA) declared obesity a disease in June 2013 and psychologists 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 that announcement.

They sought to test the hypothesis 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.

They did an online survey, over 700 participants across three different studies.

"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."

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.