FRIDAY, Sept. 2, 2005 (HealthDay News) -- If you're planning an end-of-the-summer eating marathon this weekend and figure you'll make up for it next week by cutting back on calories, think again.
The "binge-then-compensate" plan sounds good, but doesn't happen in real life, said David Levitsky, a professor of nutrition and psychology at Cornell University in Ithaca, N.Y.
"People don't under-eat after overeating," Levitsky said.
He found that out when he fed a group of normal-weight men and women, average age 31, three meals a day in his experimental dining room at Cornell, weighing every crumb.
For the first two weeks, the baseline period, they could eat as much or as little as they wanted. Most ate between 2,600 calories and 3,100 calories a day.
Next, they were all overfed, with the researchers giving them 33 percent more than they had consumed during the first two weeks.
"At the end of the 13th day, my dietitian called and said, 'The subjects are going to rebel, they can't eat another thing,' so we stopped one day early," Levitsky said.
Next, they went back to eating as much or as little as they wished for three weeks. Rather than cutting back on consumption, they returned to eating the same amount they had eaten during the first two weeks of the trial, said Levitsky, whose study appeared in a recent issue of Physiology & Behavior.
During the overfeeding phase, the men and women gained an average of five pounds. During the two-week period when they returned to eating the amount they wanted, they actually lost 2.8 pounds, even though they didn't cut back, resulting in a net gain of about 2.2 pounds.
They probably lost the 2.8 pounds, Levitsky noted, because "the more weight you carry, the greater your energy expenditure."
When you "pig out" on vacation or a long weekend, "you are not going to come back less hungry," Levitsky said. And if you come back with a weight gain and want to shed it, "you have to make some active attempts," he added.
In other studies, not yet unpublished, Levitsky and his team have found that skipping meals -- often considered bad form by dietitians -- can work to undo the damage of an eating binge.
But other nutrition experts, including Lona Sandon, an assistant professor of clinical nutrition at the University of Texas Southwestern Medical Center at Dallas, favor another approach.
Sandon suggests people stop looking at vacations or three-day weekends as an excuse to go "hog wild."
"I am not quite sure at what point in time the term 'vacation' took on the same meaning as 'all you can eat,'" she said. "The overeating associated with vacationing is a mindset that people need to change."
She suggests that a better idea is to enjoy food in moderation every day.
Because the Levitsky study only used 12 participants, Sandon also said it is "difficult to generalize to a larger population as to whether or not this is a normal response to a few days of overeating." But she said other studies have come to similar conclusions.
"What is alarming about the Levitsky study is that when people returned to normal eating, they only lost half of what they gained after overeating for just 13 days. So they were now about 2 pounds heavier than they were before the study began," she said.
When people who overeat while on holiday put themselves on a low-calorie diet upon their return, Sandon said, it usually backfires because they can't endure it for long and go back to poor eating habits.
"It turns into a vicious cycle of restricting and overindulging," she said. "The best thing to do is get back into your normal eating and exercise routine as soon as possible."
Other weight-control strategies include skipping the all-you-can-eat buffets while on holiday, focusing on the local cuisine rather than eating at chains you can find at home, and scheduling plenty of physical activities, she said.
To learn more about calorie control, visit the American Dietetic Association.