Willpower

opposite pattern. The ones who had downed the giant milkshakes actually ate more cookies and crackers than the ones who’d had nothing to eat for hours. The results stunned the researchers, who were led by Peter Herman. Incredulous, they conducted further experiments, with similar results, until they finally began to see why self-control in eating can fail even among people who are carefully regulating themselves.
    The researchers gave it a formal scientific term, counterregulatory eating, but in their lab and among colleagues it was known simply as the what-the-hell effect. Dieters have a fixed target in mind for their maximum daily calories, and when they exceed it for some unexpected reason, such as being given a pair of large milkshakes in an experiment, they regard their diet as blown for the day. That day is therefore mentally classified as a failure, regardless of what else happens. Virtue cannot resume until tomorrow. So they think, What the hell, I might as well enjoy myself today —and the resulting binge often puts on far more weight than the original lapse. It’s not rational, but dieters don’t even seem to be aware of how much damage these binges do, as demonstrated in a follow-up experiment by Janet Polivy, Herman’s longtime collaborator. Once again, hungry dieters and nondieters were brought into the lab, and some of the dieters were given food with enough calories to put them over their daily limit. Later, the entire group was served sandwiches cut into quarters. Afterward, and unexpectedly, everyone was asked how many sandwich quarters he or she had eaten.
    Most of the people answered the question with no trouble—after all, they’d just finished eating, and they knew how many sandwiches they’d taken. But one group was notably clueless: the dieters who’d been given enough food to exceed their daily limit. Some of them overestimated, and some underestimated. As a result, they were much further off the mark than either the nondieters or the dieters who were still under their daily food limit. As long as the diet wasn’t busted for the day, the dieters tracked what they were eating. But once they broke the diet and succumbed to the what-the-hell effect, they stopped counting and became even less aware than nondieters of what they were eating. As we know, monitoring is the next step in self-control after setting a goal, but how can dieters do that if they stop keeping track of what they eat? One possible alternative would be to heed the body’s signals that it’s had enough sustenance. But for dieters, that turns out to be yet another losing strategy.

The Dieter’s Catch-22
    Humans are born with an innate gift for eating just the right amount. When an infant’s body needs food, it sends a signal through hunger pangs. When the body has had enough food, the infant doesn’t want to eat any more. Unfortunately, children start to lose this ability by the time they enter school, and it continues to decline later in life for some people—often the ones who need it the most. Why this occurs has been puzzling scientists for decades, starting with some research in the 1960s that revolutionized the study of eating.
    In one experiment, researchers rigged a clock on the wall of a room where people could munch on snacks during the afternoon as they filled out stacks of questionnaires. When the clock ran fast, the obese people ate more than others, because the clock signaled to them that it must be getting close to dinnertime and therefore they must be hungry. Instead of heeding their body’s internal signals, they ate according to external cues from the clock. In another study, researchers varied the kinds of snacks that were offered, sometimes offering shelled peanuts and sometimes whole peanuts. It didn’t seem to matter to the normal-weight people, who ate about the same number of nuts either way. But the obese people ate far more when they were offered the shelled nuts, which apparently sent a stronger come-andget-it message. Once again, the obese people responded more strongly to external cues, and researchers initially hypothesized it was the cause of their problem: They became obese because they ignored their body’s internal signals of being full.
    It was a reasonable theory, but eventually researchers realized that they were confusing cause and effect. Yes, obese people ignored their inner cues, but that’s not why they became obese. It worked the other way: Their obesity made them