What fat pigs (and other animals) can teach us about our own waistlines
21:17 GMT, 30 June 2012
Around the world, doctors are wringing their hands over an obesity epidemic. But this isn’t the human outbreak you’re thinking of, nor are these the physicians you would envisage. Vets are seeing more and more overweight animals; the scale of the problem is now comparable to the human battle against the bulge.
They treat increasingly portly ponies. They instruct owners not to overfeed chubby fish. They describe tortoises so fat they can no longer pop in and out of their shells. They’ve seen so many overweight birds they have a new nickname for them: perch potatoes.
Dogs are put on diet drugs to curb their appetites. Liposuction has been the treatment of choice for obese canines whose extra flab threatens to snap their spines or splay their hips. Felines are put on the ‘Catkins’ diet – a veterinary version of the high-protein, ultra-low-carb Atkins Diet for humans.
Wild about food: Like humans, pigs, robins and orangutans will overeat given the chance
With our pets’ excess pounds has come the familiar suite of life-threatening ailments: diabetes, cardiovascular problems, musculoskeletal disorders, glucose intolerance, some cancers and possibly high blood pressure.
Despite the billions of pounds spent combating many dangerous conditions and disease in humans, few people would think of turning to a vet to look for clues to their health. Yet these animal doctors are helping fight flab every day.
Vets in North American and European zoos have placed overweight animals from flamingos to baboons on diets. If you’ve ever tallied daily WeightWatchers points, you will understand the routine of the gorillas and cockatoos at Brookfield Zoo in Chicago; the animals there have been put on a similar system.
Startlingly, wildlife biologists have begun tracking what seem to be wild-animal obesity trends, too. Over the past 40 years, yellow-bellied marmots in the Colorado Rockies, country rats in the north-eastern United States and blue whales off the coast of California have become chubbier and chubbier.
We imagine that in the wild, animals will eat until they are full and then stop. But given the chance, many wild fish, reptiles, birds, and mammals overindulge. Abundance plus access – the twin downfalls of many a human dieter – can challenge wild animals, too.
Mark Edwards, an animal nutritionist in California, noted: ‘We are all hardwired to consume resources in excess of daily requirements. I can’t think of a species that doesn’t.’
Overweight orangutan: Wildlife biologists have begun tracking what seem to be wild-animal obesity trends
Weighty issue: Humans could have more in common with pigs than we realise
When presented with unlimited food, domestic species, including dogs, cats, sheep, horses, pigs and cattle, eat nine to 12 meals a day.
Doctors’ standard advice to their overweight human patients is ‘to change your body, you must change yourself’. That’s also the directive of practically every diet book and guru. Eat less. Exercise more. Exert more willpower.
But when vets see animals getting fatter, they don’t say: ‘Those animals don’t have much willpower.’ Instead, they ask: ‘What’s going on in that animal’s surroundings’ Vets don’t see obesity as a disease of an individual; they see it as a disease of the environment.
There are a number of environmental factors beyond abundant food that make wild animals overweight. Light exposure – artificial or natural – promotes the accumulation of fat. The blend of bacteria in their intestines can lead them to harvest more or less energy from their food and become plumper.
Round robin: An animal's mental state can influence its weight
Rarely do doctors consider these factors’ effects on human weight. Of course, just as environmental changes can promote wild-animal weight gain, seasonal and other shifts lead to slimming. Cyclical periods of food scarcity are typical.
For many animals, weight goes on, but it also comes off. It’s a dynamic process. If you want to lose weight the wild-animal way, decrease the abundance of food around yourself and interrupt your access to it. In other words: change your environment.
Intriguingly, an animal’s mental state can influence its weight. Like us, anxious animals change their eating habits. The presence of predators can determine whether they nibble or gorge. Manatees eat less when sharks are prowling nearby; elk intimidated by wolves eat fewer daily meals.
Obesity isn’t the only eating problem physicians could conquer with help from their veterinary colleagues. Animals binge-eat. They hide and hoard food. They eat in secret and at night. Such types of behaviour are called ‘disorders’ by psychologists when they see them in their human patients.
Yet wildlife biologists would call them eating ‘strategies’ that enhance an animal’s survival abilities or evolutionary ‘fitness’.
Clues for treating conditions such as anorexia nervosa and binge-eating could come from the experts studying when and why such behaviour intensifies in animals.
No animals evolved to have food placed on a plate in front of them. They ran. They dug. They schemed. They starved. Eating was the reward for all that ‘work’.
But, like many pets and zoo animals, most of us in the developed world no longer worry about where our next meal is coming from.
As we increasingly outsource where and what we eat to agribusiness, supermarkets and restaurant chains, we hand over not just the inconvenience of food-gathering and preparation but also the challenge, the puzzle, and even the excitement of eating. No wonder, then, that we have an obsession with food. The urge is in our genes, it’s driven by our environments, it’s deep within.
Zoobiquity, by Barbara Natterson-Horowitz and Kathryn Bowers, is published by Virgin Books, priced 12.99. To order your copy at the special price of 10.99 with free p&p, call the Review Bookstore on 0843 382 1111 or visit mailshop.co.uk/books.