Stealth Health

While companies use wobbly terms like "all natural" and "low carb" to attract health-conscious customers, others are making healthy modifications in secret, to avoid scaring customers away.

Notoriously unhealthy products like cookies and french fries don't attract health seekers, the companies argue, so reducing salt and fat are not really selling points.

Their decisions are backed by research. For example, a 2012 study from Deakin University in Australia showed that participants did not like low-salt labeled soups as much as the same soup with a normal label, and would add extra salt to compensate.

In some cases, experience also supports the use of a so-called 'stealth health' strategy. McDonald's was barraged with complaints in 2002 after announcing they were reducing trans fats used in frialators – even at restaurants that were still using the same oil.

Boston Market cut sodium from many of its side dishes last year, but decided not to advertise the change, according to the Wall Street Journal. A previous experiment in removing salt shakers from tables did not sit well with the chain's regulars.

Whatever Works

Jennifer Harris, the director of marketing initiatives at the Rudd Center for Food Policy & Obesity at Yale University, said she supports the companies' choice to make changes quietly.

"I think it's a smart strategy. Probably the companies who are doing this are more foresighted than the ones that aren't."

The U.S. Food and Drug Administration has been ruminating over decreased sodium recommendations for years, and Harris applauds companies for voluntarily preparing for such changes by slowly changing recipes.

Once you're in the restaurant all the environmental cues are pushing people to unhealthy food.

"If it's a drastic change, loyal customers will notice it and complain. But if you make the adjustments gradually, you really can do it," without blowback, she said. "It shows that people's tastes are very malleable."

Flipside

Harris is careful to point out that companies don't always hide healthy changes. "It's simplistic to say that people won't like healthy food," she said.

A new product is much easier to adjust than a fast food item with a long legacy. While companies may want to hide healthier modifications on fast food items, some brands have attracted customers with low-salt or low-calorie labels.

"What we see much more commonly is that companies will take an unhealthy product and call it 'all-natural' or say it has 'no artificial ingredients' or that it's a good source of vitamin C," Harris said.

Healthy Bait

Sometimes healthier options at fast food restaurants don't do well. McDonald's salads only make up 3 percent of the chain's sales in the U.S. Harris said that such products are used to encourage health-oriented customers to enter the restaurant, but once inside they're likely to choose something off of the regular fat-and-salt laden menu, or add a fountain soda to triple their calorie count.

"Once you're in the restaurant all the environmental cues are pushing people to unhealthy food," she said.

So when fast food companies claim their customers don't want healthy food, Harris takes it with a grain of salt.

"I always find it disingenuous for the fast food restaurants to say 'well, we've tried introducing healthy stuff and it just didn't work,'" she said. "They're not really trying to make these products as appealing as possible when someone's in the restaurant."

Read More:

• Less Salt, Same Taste? Food Companies Quietly Change Recipes (Wall Street Journal)
• Fast Food Facts 2013 (Yale Rudd Center For Food Policy And Obesity)