If you're wondering whether indulging in that one holiday cookie or slice of pie will send your diet into a free-fall, a new study suggests that the answer is "maybe."

In a set of studies where college students were tempted by chocolate truffles, researchers found that one little truffle was capable of stoking participants' desire for more sweet and fatty treats — but only under certain conditions.

It all depended on how the situation was "framed," explained Dr. Chris Janiszewski, a professor of marketing at the University of Florida, Gainesville and one of the researchers on the work.

The findings suggest that if a person were to pop a truffle without much thought — vaguely thinking, "I'll just have a little taste," for example — it might lead to a slippery slope of indulgence, Janiszewski told Reuters Health.

The situation may be entirely different, however, when a person has goals, he and colleague Juliano Laran report in the Journal of Consumer Research.

In one study, the researchers presented the students with the same chocolate truffle temptation. This time, however, participants in one group were told their goal was to allow themselves "one treat per day." Those in a second group were told that resisting the truffle allowed them to "accomplish their healthy eating goal."

In the end, the group that indulged in the treat was more likely to want healthier fare afterward — like salads, fruit and yogurt. In contrast, those who'd exercised restraint around the truffles, apparently feeling their mission was accomplished, were more likely to want indulgent treats than healthy snacks later on.

That last finding is particularly interesting, Janiszewski noted, because it implies that "not eating the truffle can be just as damaging as eating it."

So what's a diet-conscious holiday reveler to do?

Janiszewski pointed out that no study can predict what any one person will do when faced with temptation. Still, the results suggest that the way people think about snacking, or not snacking, is key.

Rejecting a treat then "declaring victory," Janiszewski said, could lead to indulgences later in the day. In contrast, someone who decides that his holiday treat will be saved for after dinner, with no more treats to follow, might fare better.

And as always, Janiszewski noted, a modest portion is better than a super-sized one.