Monkey diet sheds light on origin of human obesity


Bridie Smith
May 25, 2009

Some monkeys manage their diet in a similar way to humans, suggesting the origin of human obesity could go back earlier than previously thought, according to new research.

Annika Felton, who spent a year studying the individual feeding habits of 15 Peruvian spider monkeys as they moved around the canopy of the Bolivian rainforest, found the herbivore monkeys controlled their daily protein intake in a similar way to humans. The findings could shed new light on the ancient origins of human obesity.

Dr Felton found the monkeys, who travelled between 2 and 6 kilometres a day, had a consistent daily protein intake of between 11 and 12 grams regardless of the season or whether they ate fruit only or added higher-protein leaves and shoots to their diet.

"In the fruit season they can have a 100 per cent fruit diet and still get the protein they need but they do it by gorging themselves and eating [the low protein fruit] until they reach their protein target," she said.

Dr Felton said like humans, if a monkey's diet was poor in protein but rich in energy-dense carbohydrates and fats, monkeys will keep consuming food and energy until they reach their protein target. This can make for a high-energy diet, which can lead to weight gain.

"If anything, we as humans can learn from them," she said. "It's not the dieting, it's the activity. We shouldn't overeat in our quest to reach the protein target, which is what's going on in many western countries."

Sweden-based Dr Felton, a departmental visitor at the Fenner School of Environment and Society at the Australian National University, said humans' susceptibility to obesity could date as far back as 40 million years, instead of about 10,000 years.

Source: The Sydney Morning Herald