Avid exercisers may want to add one more activity to their work-out routine: sleep.

Northwestern researchers Joseph Bass and Fred Turek published an editorial in the Jan. 10 issue of the Archives of Internal Medicine citing lack of sleep as a possible factor in the nation’s obesity crisis.

According to Bass and Turek’s report, a 1999 study performed in Virginia found that when subjects slept only four hours per night for a week, noticeable changes in their metabolism occurred. These changes are similar to those observed in people with diabetes.

On a practical basis, however, missing out on one or two full nights of sleep was not a cause for concern, Bass said.

Sleep is only one of several behavioral habits, including eating and exercising, that have been linked to obesity, but it remains a mysterious aspect of the problem, Bass said.

Some doctors still doubt the significance of these findings.

“Having read the review of Dr. Bass, the creative take home is ‘wait and see,'” said Stephen Duck, a pediatric endocrinologist at Evanston Northwestern Healthcare, in an e-mail to The Daily. “Until the data is confirmed and explained, correlation does not become cause.”

More than half of all American adults are overweight and the obesity rate for college students has more than doubled since last decade, according to Bass and Turek’s “Sleepless in America: A Pathway to Obesity and the Metabolic Syndrome?”

“We still don’t understand how the environment and genetics interact to affect behavior,” Bass said.

Although many people focus on the cosmetic effects of obesity, medical professionals increasingly are voicing concern about potentially fatal health problems associated with being severely overweight.

Diabetes, hypertension and other chronic diseases related to obesity can lead to what Bass calls “metabolic syndrome,” a disease that affects 47 million Americans. Metabolic

syndrome is linked to the pathways controlling

appetite centers in the brain.

“Metabolic syndrome is on the rise worldwide, (due to) abnormalities in how the body metabolizes sugar,” said Bass, professor of neurobiology and physiology in the Weinberg College of Arts and Sciences.

Bass said he wants to “remove the emotional aspect” of these studies, an aspect he says stems from Americans’ prejudice against overweight people. He said obesity should not be regarded as a “personal weakness or internal flaw.”

Students said they were not surprised at the idea that sleep loss could be linked to obesity, considering the irregular and hectic lifestyle of college students.

Weinberg freshman Jessie Nock, who gets seven to eight hours of sleep per night, said it makes sense that lack of sleep could alter eating patterns.

“If you’re getting less sleep, you have less energy and try to make up for it by eating more,” Nock said.

Communication sophomore Cait Ruegger said common sense indicated there should be a link between not sleeping and eating more.

“When you’re sleeping, you’re not doing anything to occupy your hands and mouth,” she said.

Kyle Eck, a Communication freshman, said he and his suitemates at the Public Affairs Residential College order pizza at 12 to 1 a.m. three or more nights per week, but he does not attribute such habit to idleness.

“I don’t know if it would have to do with be being idle as much as being hungry,” Eck said. “I think a lot of it stems from having different hours and not having breakfast. We’re hungry at that hour.”

Ruegger said she won’t change her sleep regimen, even if doctors prove lack of sleep will lead to weight gain.

“My habits are built around doing homework,” she said.

The Daily’s Alexander Pegg contributed to this report.

Reach Tara Jayant at [email protected].