Public Health Messages About Losing Weight Can Have Undesired Effects

Social media bombards us with advice about how to lose weight, telling us what, how much, when, and when not to eat in order to shed those extra pounds. But, sometimes we are also told that diets actually don’t work in the long run because we are destined to regain the weight.  What message should you believe?

Although both of these messages have the goal of trying to help people live healthier and happier lives, they portray the nature of weight and weight loss very differently. Obviously, advice that tells us how to lose weight suggests that we can change and may provide us with an important sense of confidence that we can successfully lose weight. In contrast, telling people that diets usually fail because of how the human body works suggests that keeping weight off permanently is impossible. And, reminding people why diets don’t work in the long run may help people feel less bad about their weight. However, we wondered if this message might also lead to unexpected outcomes.

In a research study we conducted with Fanice Thomas and Ali Babij, we asked people to read one of two articles. Half of the participants read an article that described how biology and evolution work against permanent weight loss, concluding that in the long run, diets don’t work.  The other half of our participants read an article describing how you can lose weight by making healthier choices, leaning on others, and not blaming yourself for weight-loss struggles. After reading one of these two articles, the participants answered questions about their weight-related beliefs, attitudes, and behaviors.

First, although you might expect that describing why dieting fails for most people would lead to the conclusion that overweight people aren’t responsible for being overweight, we did not find this to be the case. The message that “diets don’t work” did not reduce participants’ belief that individuals are to blame for their current weight.

Second, people who read about why diets fail, compared to those who read about how to lose weight, doubted their potential to ever lose weight in the future.  Furthermore, these participants who reported less confidence about losing weight also reported feeling more body shame and an excessive desire to be thin. For example, they agreed more strongly with statements such as “the appearance of my body is embarrassing,” and they reported engaging in unhealthy strategies to lose weight.

Third, participants who read the article about why diets fail also believed that, once people are obese, they are destined to be overweight forever. And, this belief was related to more negative attitudes toward people who are overweight. 

In summary, the message that diets don’t work failed to reduce blame for being overweight, and it also had hidden costs. Simply reading the article that described the science behind why cutting calories is a useless strategy led to less confidence and a sense of doomed fate. And, these beliefs related to feeling more shame about one’s body and greater prejudice toward those who are overweight.

What now? The story about weight-loss is complicated, and many people do struggle with long-term success. Thus, it is accurate to tell people about the physical, social, and cultural factors beyond their control that lead to weight-gain.  But, it is also critical to make sure that people who wish to lose weight feel like future change is possible.

For Further Reading

Hoyt, C. L., Burnette, J. L., Thomas, F*., & Orvidas, K*. (2019). Public health messages and weight-related beliefs: Implications for well-being and stigma. Frontiers in Psychology, 10, 2806. https://doi.org/10.3389/fpsyg.2019.02806

Jeni L. Burnette is an Associate Professor of Psychology at North Carolina State University.

Crystal L. Hoyt is a Professor of Leadership Studies and Psychology and is Associate Dean for Academic Affairs, Colonel Leo K. & Gaylee Thorsness Endowed Chair in Ethical Leadership at the University of Richmond.