Marketed as a healthy substitute for candy bars, touted for their high protein and low sugar content, protein or fitness bars marketed as good nutrition for fitness-conscious consumers — such as Clif, Power Crunch, or Muscle Milk — may actually do more harm than good. That's because they lead those who are conscious about their weight into a false sense of security.

“Fitness branding” tends to promote eating more and exercising less which can undermine our fitness goals, and thwart our efforts to lose or maintain weight, according to a new study published in the Journal of Marketing Research.

The package for the “Fitness” snack had an image of running shoes added to make it appear healthier.

“Unless a food was forbidden by their diet, branding the product as ‘fit’ increased consumption for those trying to watch their weight,” the authors write. “To make matters worse, these eaters also reduced their physical activity, apparently seeing the ‘fit’ food as a substitute for exercise.”

People in the study were given a trail-mix type snack labeled as either “Fitness” or “Trail Mix.” The package for the “Fitness” snack had an image of running shoes added to make it appear healthier. The people in the study were told to pretend they were at home and eating an afternoon snack. They were asked to taste the product and evaluate it. Then they were given the option to get on a stationary bicycle and exercise as much as they wanted.

The participants who were trying to watch their weight ate much more of the “Fitness” snack and worked out less during the exercise phase of the study, presumably because they felt they didn’t need to exercise so hard.

The authors of the study say it's important to pay more attention to fitness cues in marketing. “Reminding the consumer that exercise is still necessary may help counteract the negative effect of these fitness-branded foods.”

Fitness foods, however they are marketed, still contain calories. To work off a protein bar with 300 calories, you would have to walk for an hour at 3.5 mph, or you could play Frisbee for 80 minutes or jump rope non-stop for 25 minutes.

Don't be fooled: “Fitness” foods are not a replacement for physical activity and can actually undo much of your hard work.