By Sara Novak, Planet Green
The American obesity epidemic has become a hot topic of news. And with good reason considering we’re the fattest nation in the world and we’re only getting fatter. But a new study led by David Allison, a biostatistician at the University of Alabama at Birmingham, published in the Proceedings of the Royal Society B and reported in Scientific American has shown that animals are experiencing the same problem. And this isn’t just household pets as you may expect, it’s animals that live anywhere close to humans.
Allison and his team examined the changes in weight of 24 different species, 12 male and 12 female. Some of the varied species included household pets like cats and dogs as well as feral rats that live near humans. The researchers tracked weight gain per decade.
According to the study:
Because there were no clear guidelines for what animals should weigh, the authors defined obesity as the weight above the 85th percentile in each group at the earliest time point for which they had data. Both the percentage increase in body weight and the odds of an animal being overweight in a given population showed a strong trend upwards.
So what’s causing animals to get fatter? Why are dogs and cats becoming more susceptible to weight gain along with farm animals and rodents? Both the study authors and other relevant animal experts came to conclusions about why so many species were fattening up, many of which may surprise you.
Related: American Pets Getting Fatter
1. Richer Table Scraps
According to the study:
The more than 40 percent jump in body weight in feral rats scavenging on the streets of Baltimore may reflect the increasing richness of their diet as they feed on our more calorie-dense refuse.
Animals that feed on our table scraps are getting as fat from it as we are. Fifty years ago our table scraps were less likely to be an extra value meal from your local fast food chain and this is true of household pets as well. If you’re feeding them human food and you don’t eat healthy, they won’t be eating healthy either.
2. An Indoor Lifestyle
Nearly 89 million American pets are overweight or obese according to the Association for Pet Obesity Prevention. And just like in humans, such weight problems put them at risk of diabetes, arthritis, high blood pressure, and a multitude of other diseases.
Like person like pet, our household pets follow our directions. If you’re active and love playing outside, you’re more likely to take your pet on walks, throw the ball outside, and take them on hikes. On the other hand, our increasingly indoor society means that animals are spending more and more time asleep on the couch while we watch television. Your cat may watch a bird on the tube, rather than venturing outside to catch it. According to Cairn Rescue, outdoor cats and house cats that roam outside typically do not get fat. It’s cats that are left indoors that suffer from boredom and lack of exercise.
Related: Jog With Your Dog
3. Toxins in Our Water Supply
I’ve talked about pollution in our water supply before that results from a range of toxins and pharmaceuticals. According to the New York Times, an EPA survey of 139 streams around the country revealed that 80 percent of samples contained residues of drugs like hormones, painkillers, blood pressure medicines, or antibiotics. Allison and his team found that toxins in the water supply disrupt the endocrine system of animals which can literally slow down a mammal’s metabolism.
4. Spoiling Our Pets
We tend to spoil our household pets especially if we feel guilty for leaving them alone for much of the day while we’re at work. Some pet treats contain too many calories, just like human snack foods. Some of the larger dog chews can contain as much as 600 calories, which for some dogs is more than a daily allowance of calories, according to the Association for Pet Obesity Prevention. Dog treats are nutrient dense and this coupled with feeding our dogs junk food from the table makes for an overweight pup.
5. Disrupting Hibernation and Migration
Until recently, my advice to an overweight human would have been following the time honored advice of our fellow mammals and bird species: eat when you’re hungry and stop when you’re full and get some exercise each day. This is because animals genetically listen to their bodies more than humans. The only problem is that we’ve disrupted the habits of animals so much that even they keep getting fatter. According to the study, certain environmental factors could be affecting body-weight cycles in migrating and hibernating animals. In the wake of climate change, for example, some animals have stopped hibernating and others have shortened their seasonal migration routes. Migration routes are threatened by habitat destruction as well. I wrote over at TreeHugger that such destruction presents an acute threat to the survival prospects of the pronghorn antelope in the American west for example. Poor land use can fragment the pronghorn’s migration pattern and adversely affect the species’ natural cycles. When they don’t travel as far, they’re don’t burn as many calories.