• You lookin' at my belly? (Thanks to Clement Laksana for the photo.)

Scientists are fattening up our primate cousins in an effort to better understand why we're so fat.

“We are trying to induce the couch-potato style,” said Kevin L. Grove, who directs the “obese resource” at the Oregon National Primate Research Center here. “We believe that mimics the health issues we face in the United States today.”

The corpulent primates serve as useful models, experts say, because they resemble humans much more than laboratory rats do, not only physiologically but in some of their feeding habits. They tend to eat when bored, even when they are not really hungry. And unlike human subjects who are notorious for fudging their daily calorie or carbohydrate counts, a caged monkey’s food intake is much easier for researchers to count and control.

“Nonhuman primates don’t lie to you,” said Dr. Grove, who is a neuroscientist. “We know exactly how much they are eating.”

To allow monitoring of their food intake, some of the obese monkeys are kept in individual cages for months or years, which also limits their exercise. That is in contrast to most of the monkeys here who live in group indoor/outdoor cages with swings and things to climb on.

While this research is not entirely new and has been the target of some animal rights’ group complaints, demand for the overweight primates is growing as part of the battle against the nation’s obesity epidemic, according to Dr. Grove and other researchers working with such monkeys in Florida, Texas and North Carolina, and also overseas.

Some tests have already produced tangible results. Rhythm Pharmaceuticals, a start-up company in Boston, tested its experimental diet drug on some of the Oregon monkeys. After eight weeks, the animals reduced their food intake 40 percent and lost 13 percent of their weight, without apparent heart problems.

Read the rest of this New York Times article, by Andrew Pollack, here.