If you're trying to eat right, then eating out can be a challenge. Just choosing a restaurant with a healthy image isn't enough to ensure that you're getting a healthy meal, however. That much was proven by researchers who found that diners eating at Subway routinely underestimated the number of calories in their meal. Not only that, diners who ordered subs also were more likely to add on a high-calorie side item, apparently because they thought their meal was light enough to warrant it. But when you put a 12-inch BMT and a Big Mac side-by-side, the BMT actually has an additional 300 calories!

The study authors insist they aren't trying to slam Subway, but are just trying to draw attention to the role marketing plays in people's eating habits. Subway -- and other similar restaurants -- can offer you a healthy lunch, you just have to be a savvy consumer.