newjerseynewsroom.com

BY JOHN SOLTES

NEWJERSEYNEWSROOM.COM

Indonesian orangutans may help scientists understand the underlying reasons for eating disorders and obesity in humans, according to new research from an evolutionary anthropologist at Rutgers University.

Erin Vogel, who recently published the results of her five-year study in the journal Biology Letters, looked at how orangutans survived during times of extreme food scarcity. The extensive research is the first time a scientist has explored the relationship between the apes and their protein deprivation, according to a news release from Rutgers.

“There is such a large obesity epidemic today and yet we don’t really understand the basis of the obesity condition or how these high-protein or low-protein diets work,” Vogel said. “I think studying the diets of some of our closest living relatives, the great apes, may help us understand issues with our own modern-day diets.”

In her field studies, Vogel observed that the orangutans added extra pounds only during periods of high caloric and protein intake. “The orangutans put on fat when caloric intake is greatest, and this also coincides with a period of high protein in the diet,” Vogel wrote in an e-mail to New Jersey Newsroom. “What (our) study does is demonstrate that when caloric intake is high, orangutans are able to store fat due to excess calories in their diet.”

When the calorie levels dropped, the apes started burning their stored fat and breaking down muscle tissue. “For orangutans, it is caloric intake, not necessarily the amount of carbohydrates or protein or fat, that seems to be most important for weight gain or weight loss,” she continued.

Vogel, an assistant professor of anthropology at the School of Arts and Sciences, gathered the data for her study by examining urinary metabolites and nitrogen stable isotopes.

“We discovered through this research that the daily amount of protein the orangutans take in when fruit is not available is inadequate for humans and one-tenth of the intake of mountain gorillas,” she said. “But it is sufficient to avert a severe protein deficit.”

The Bornean orangutan population in Indonesia hovers at 55,000. On the island of Sumatra, less than 5,000 survive, due to illegal logging and new palm oil plantations.

Vogel has a history studying primates. For her PhD dissertation, she investigated why capuchin monkeys fight over food.

Her next step in the orangutan study is to look at different habitat types in Borneo and Sumatra to see whether the patterns continue.

“There is a large amount of variation in diet among orangutan populations in different habitat types and this variation very well could be linked to variation in craniodental traits and the ability to assimilate protein rich foods,” said Vogel. “We will explore if these periods of nutritional stress are related to variation in the immune response of these animals.”

John Soltes is an award-winning freelance journalist based in New Jersey. He currently serves as publisher of Hollywood Soapbox (www.HollywoodSoapbox.com). E-mail him at This e-mail address is being protected from spambots. You need JavaScript enabled to view it .