Obesity research may be misrepresented by scientists working on bias topics, says UAB study

Dec 1 2009

A new study by researchers at the University of Alabama at Birmingham (UAB) School of Public Health shows that obesity research may be misrepresented by scientists operating with particular biases on topics related to weight, nutrition and the food industry.

The researchers refer to "white-hat bias," a tendency to distort information about products such as sugar-sweetened beverages or practices like breastfeeding, regardless of the facts, when the distortions are perceived to serve good ends. The name for the bias is a reference to do-good characters often portrayed in early Hollywood Westerns as cowboys who wore white hats.

The findings, published in the International Journal of Obesity, reveal biases sufficient to mislead readers, says public health professor David B. Allison, Ph.D., director of UAB's Nutrition and Obesity Research Center and study co-author.

"White-hat bias is a slippery slope that science and medicine need to resist; hopefully our study sounds a warning bell," Allison says. "The field of obesity must be vigilant to minimize and remove these biases."

Allison worked with his co-author Mark Cope, Ph.D., formerly a UAB research associate and now a scientist at Solae LLC in St. Louis. They examined ways in which scientists writing new research papers referenced two studies reporting effects of sugar-sweetened beverages on body weight. The UAB study did likewise with a lengthy World Health Organization report on the protective effects of breastfeeding.

According to Allison and Cope, less than one-third of the papers that cited the beverage studies accurately reported the overall findings, and more than two-thirds exaggerated evidence that reducing sugar-sweetened drink consumption reduced weight or obesity. The UAB researchers also found several examples in the breastfeeding studies in which the authors selectively included some data and discarded other research to support the theory that breastfeeding decreases the risk of obesity.

For both the beverage and breastfeeding research, the resulting data was more likely to be published when it showed statistically significant outcomes. Studies with outcomes that did not show sugar-sweetened drinks to be bad and breastfeeding to be good were less likely to be published. Notably, this bias appeared in studies not funded by industry, Allison says.

"Some researchers like to demonize certain products or defend practices with a kind of righteous zeal, but it's wrong to stray from truthfulness in research reporting," Allison says.