A study of weight loss in grizzly bears may hold important implications for human dieting.
The study comes from Barbara Natterson-Horowitz, a key member of One Health, an initiative tht espouses collaboration between physicians and veterinary practices.
"Until recently, the veterinary world has existed in a parallel universe to human medicine, and there has been no cross talk," Associate Professor of Medicine at Yale Medical School Peter Rabinowitz said. "There are so many things that vets have discovered that are relevant to doctors in practice, and vice versa."
Natterson-Horowitz's 2012 book Zoobiquity, which she co-wrote with science writer Kathryn Bowers, reveals a number of these discoveries. These range from binge-eating grasshoppers to drug-addicted wallabies, even to obese grizzly bears.
Natterson-Horowitz's chapter on grizzly bears chronicles Jim and Axhi, a pair of formerly obese Alaskan grizzlies residing at Brookfield Zoo in Chicago. The Brookfield Zoo vets realized that the obesity of the grizzly bears was primarily a factor of their environment. Since they couldn't tell the bears to count calories or get more exercise, they implemented what Natterson-Horowitz has termed "nature's weight management plan."
Specifically, nutritionists at the Brookfield Zoo replaced the bears' diet of ground beef, bread loaves, processed dog food, supermarket oranges, mangoes, bananas and iceberg lettuce with animal protein and plants that were both seasonal and were more closely aligned with what the grizzly bears would typically find in their natural habitat. They also put an end to a fixed schedule for delivering food, instead hiding meals and adding wax-worms to the bears' foraging piles, which helped the bears burn calories. As a result, the grizzly bears lost hundreds of pounds over the course of a year.
Natterson-Horowitz feels that this same environmental approach can be crucial in an effective human weight loss strategy.
"I see a lot of patients who are overweight," she said. "I talk to them about what they are eating, about activity, about what is going on with them psychologically. But it is all targeted at them as an individual. Vets, on the other hand, have a very different approach. When they notice that an animal is getting fatter, they don't look to the individual but to the environment."
According to Natterson-Horowitz, one simple way to prevent over-consumption is to empty food stockpiles in the purse, glove compartment and workplace. Another strategy is to do at most a few days' worth of grocery shopping instead of purchasing large amounts of food. Food purchases should be largely centered around items that are locally grown and less processed, but not necessarily those that are certified organic. Since vegetables and fruit found in grocery stores are tailored for shelf life, they can have less nutritional value than traditional items. Traditional whole grains like farro and barley contain fewer calories while being more filling and nutritious than the varieties of white rice and refined wheat.
Buying from farmers markets or even growing your own food can not only lead to a more nutritious diet, but can also make humans more active food consumers. While certainly not as extreme as the hunting activities undertaken by bears, these measures can incline consumers away from the passivity of grocery-store strolling or fast food window drive-bys.
On top of their other strategies, employees of the Brookside Zoo also increased the richness of the grizzly bears' environment, filling their cages with numerous distractions that reduced stress and boredom: two factors related to overeating. Such healthy distractions could also play an important role in human weight loss.
Of course, Natterson-Horowitz's study on grizzly bears cannot be taken too literally; however, there is something to be said for a reminder of the lessons nature teaches us.
As Associate Clinical Professor of Family and Community Medicine at the University of California at San Francisco Medical School Daphne Miller wrote in a Washington Post article about the study, "The lesson of Zoobiquity is that we are simply exercising our animal natures in an environment that is anything but natural ... perhaps it's time that we take a cue from Jim and Axhi, and start to live a little more on the wild side."
