We are at risk of piling on the pounds even if we are eating foods marketed as 'healthy'.
That is the findings of a study carried out by a team at the University of Ulster which has shown that people believe they can eat more of the foods that are deemed better for us.
The research also indicates that many people assume that foods with certain health claims are lower in calories than they actually are.
Cliodhna Foley Nolan of Safefood Ireland says those tested consumed up to 30 to 80 percent more of the perceived healthier product.
"They were given say two types of - say - cereal, or two types of drink, or two types of coleslaw; one which was called a healthier versions and one which was called standard" she said.
"In fact, the two of them were the exact same amount of calories".
"But we found that when they thought that something was healthier, or had been marketed as that, that they ate a lot more of it" she added.