"There's so much in the media and so much publicity about what's a healthy food, what's not a healthy food, and we think we're making a healthy choice but we're really not," said Shelly Lummus, R.N., weight loss expert.
Nurse practitioner Shelley Lummus is talking about a phenomenon called the 'health halo.'
"The health halo effect is what we find when people go to what they deem to be healthful restaurants, and they tend to overeat because they think they're eating healthy," said Patricia Bannan, dietitian.
"Our thought process is, well it's healthy so I can eat as much as I want," said Lummus.
In a study known as the "McSubway" project, researchers found generally we tend to underestimate the number of calories we consume, but to a greater extent when eating at a healthy establishment.
For example, those who ate 1,000 calories at McDonald's estimated they ate 744 calories. Yet those who ate a 1,000 calorie Subway meal thought they were eating just 585 calories.
"I usually go with the Baked Lays, but not today," said Michael Owens.
Like many donning a 'health halo,' Mike Owens added calorie rich extras like chips and soda.
"Maybe a cookie or something too in the end," said Owens.
Rather than put the breaks on dining out, arm yourself with nutrition facts instead.
"If they don't have it in a convenient place when you walk into a restaurant or a fast food place, you can get it online," said Lummus.
When you realize the items on the light menu can be between 700 and 1,000 calories, you'll no doubt have sticker shock when you see the calorie counts on regular entrees. Even if your restaurant doesn't have nutrition facts, you're going to want to follow one rule of thumb.
"Take your best guestimate and then double it. It's going to be more accurate indication of what you're actually eating," said Bannan.
In addition, experts say those who exercise also wear this halo.
"They think, I worked out today, I burned so many calories on my machine and says I can now have a cookie or I can eat extra food," said Bannan. "What we find is when people eat out they underestimate their calories, when they workout they overestimate what they burn."