More than half (53%) of U.S. adults take dietary supplements, according to a new government survey conducted from 2003-2006, up from about 42% in 1988-1994. Sounds great, right? But if supplement usage continues to increase over time, why hasn’t public health improved in turn?

A study published in an upcoming issue of Psychological Science noted that people who take dietary supplements may have the misconception they are invulnerable to health problems and may make poor decisions when it comes to their health—such as choosing fast food over a healthy and organic meal.

Results from the study demonstrated that participants who believed they had taken dietary supplements felt invulnerable to health hazards, leading them to engage in behaviors that put their health at risk. Specifically, participants who believed they were taking dietary supplements expressed less desire to engage in exercise and more desire to engage in hedonic activities, preferred a buffet over an organic meal and walked less to benefit their health compared to the control group.

“People who rely on dietary supplement use for health protection may pay a hidden price, the curse of licensed self-indulgence,” said Wen-Bin Chiou of National Sun Yat-Sen University, who conducted the study along with Chao-Chin Yang of National Kaohsiung University of Hospitality and Tourism and Chin-Sheng Wan of Southern Taiwan University.

It’s almost like the French Paradox in reverse. Even when some people “try” to be healthy, the now-global culture of over-consumption keeps weighing them down, literally and figuratively.

While responsible industry representatives continue to stress that dietary supplements aren’t designed to replace a healthy diet and exercise, the compulsion to eat that greasy double cheeseburger is tough to overcome. In the end, people will look to justify their personal decisions any way they can—however flawed their logic may be.

Sure, there’s a strong constituent of supplement users who actually lead healthy lifestyles and understand the true role that supplements are meant to play. However, I think some of those double-cheeseburger-with-fries-inclined supplement users need a little more help, a little more education and a little more time at the gym to see their investment pay off.