Researchers studied consumer behaviour with regard to so-called 'mini-packs', which are marketed to help people control their calorie intake.
They found that consumers tended to regard the packs as 'diet food' but overestimated how many calories they contained, meaning that they often ate more than they would normally have eaten.
The authors found that chronic dieters commonly over-consume mini-packs.
Writing in the Journal of Consumer Research, they claimed: "On the one hand, consumers perceive the mini-packs to be a generous portion of food (numerous small food morsels in each pack and multiple mini-packs in each box); on the other hand, consumers perceive the mini-packs to be diet food."
They added that, in the case of chronic dieters, this dilemma causes a tendency to overeat "due to their emotion-laden relationship with food".
The researchers concluded that, while restrained eaters may be attracted to mini-packs, they actually tend to eat more of the product than they would of regular foods.