Clearer food labels might help with healthy food choice: study

To make products appear healthier, some companies have started increasing the number of servings listed per container, thus lowering the number of calories per serving. All of that adds to consumers' confusion, she said.

Researchers warned that it's still not known whether clearer nutrition facts would change what people choose to buy or eat, and it's also unclear if and when the FDA might issue changes to labelling requirements.

But having a system that lists the nutrients for one serving and an entire package - as some products do already - would help simplify things, Mohr said.

"It's so important to make the information as transparent as you can make it for consumers," she said.

Marion Nestle, a nutrition researcher from New York University, agreed, echoing Mohr's recommendation of a system like Britain's - in which the front of foods are labeled green, yellow or red on basis of their healthfulness.

"If you give somebody a big package of potato chips, they're not going to think there are five servings in it, they're going to think it has 100 calories," she said.