Personal-health coverage began to move to the fore in the late 1980s, in line with the media’s growing emphasis on “news you can use.” That increased attention to personal health ate into coverage of not only other science, but also of broader healthcare issues. A 2009 survey of members of the Association of Health Care Journalists found that more than half say “there is too much coverage of consumer or lifestyle health,” and more than two-thirds say there isn’t enough coverage of health policy, healthcare quality, and health disparities.

The author of a report based on that survey, Gary Schwitzer, a former University of Minnesota journalism researcher and now publisher of healthcare-journalism watchdog HealthNewsReview.org, also conducted a study in 2008 of 500 health-related stories published over a 22-month period in large newspapers. The results suggested that not only has personal-health coverage become invasively and inappropriately ubiquitous, it is of generally questionable quality, with about two-thirds of the articles found to have major flaws. The errors included exaggerating the prevalence and ravages of a disorder, ignoring potential side effects and other downsides to treatments, and failing to discuss alternative treatment options. In the survey, 44 percent of the 256 staff journalists who responded said that their organizations at times base stories almost entirely on press releases. Studies by other researchers have come to similar conclusions.

Thoughtful consumers with even a modest knowledge of health and medicine can discern at a glance that they are bombarded by superficial and sometimes misleading “news” of fad diets, miracle supplements, vaccine scares, and other exotic claims that are short on science, as well as endlessly recycled everyday advice, such as being sure to slather on sun protection. But often, even articles written by very good journalists, based on thorough reporting and highly credible sources, take stances that directly contradict those of other credible-seeming articles.

There is more at stake in these dueling stories than there would be if the topic at hand were, say, the true authorship of Shakespeare’s plays. Personal healthcare decisions affect our lifespan, the quality of our lives, and our productivity, and the result—our collective health—has an enormous impact on the economy. Thirty years ago, misleading health information in the press might not have been such a problem, since at the time physicians generally retained fairly tight control of patient testing and treatment decisions. Today, however, the patient is in the driver’s seat when it comes to personal health. What’s more, it is increasingly clear that the diseases that today wreak the most havoc—heart disease, cancer, diabetes, and Alzheimer’s—are most effectively dealt with not through medical treatment, but through personal lifestyle choices, such as diet, exercise, and smoking habits.

Consider the potential damage of bad weight-loss-related journalism. Obesity exacerbates virtually all major disease risks—and more than one in 20 deaths in the US is a premature death related to obesity, according to a 2007 Journal of the American Medical Association study. Obesity carries an annual price tag of as much as $5,000 a year in extra medical costs and lost productivity, for a total cost to the US economy of about $320 billion per year—a number that could quadruple within 10 years as obesity rates climb, according to some studies. (There is, of course, a lot of uncertainty in cost projections, and this research does not account for the impact of the Affordable Care Act.) On top of these costs are the subjective costs of the aches, discomforts, and compromised mobility associated with obesity.

David H. Freedman is a contributing editor at The Atlantic, and a consulting editor at Johns Hopkins Medicine International and at the McGill University Desautels Faculty of Management.