But are these diets really better for our pets? Veterinarians and animal nutrition researchers say that’s probably not the case.
According to According to clinical veterinary nutritionists at Tufts University, grain-free foods were one of the fastest-growing areas of the pet food market in 2016. “All I hear is, oh , with a good diet, it’s grain-free,” said Dena Lock, a veterinarian in Texas. The majority of his patients are overweight.
Why have these pet diets become so popular?
“It’s a marketing trend,” Lock said.
“Grain-free is marketing. It’s just marketing,” said Cailin Heinze, a small animal nutritionist at the Cummings School of Veterinary Medicine at Tufts University. “Many foods market themselves based on what they don’t include,” implying that the excluded ingredient must be bad.
“Grain-free is definitely a marketing technique that has been very successful,” said Jennifer Larsen, a clinical nutritionist at the veterinary school at the University of California, Davis. (Disclosure: I went to graduate school at the University of California, Davis, but I studied plants, not pets.) People think that if they pay a lot for food and it there are a lot of exclusions on the bag, the food is healthier. , but “they’re buying an idea,” she said, “not necessarily a premium product.”
There is absolutely no data to support the idea that grain-free diets are better for pets, Heinze and Larsen noted.
Some pet owners are under the false impression that grains are more likely to cause an allergic reaction, but “it’s much more common for dogs to be allergic to meat than to grains,” Heinze said. Chicken, beef, eggs, dairy, and wheat are the most common allergies in dogs. And it’s not that these foods have anything particularly allergenic, she said, they’re just the most frequently used ingredients.
Marketing campaigns for products such as Blue Buffalo’s “Taste of the Wild” or “Wilderness” claim that their grain-free, meat-based formulations better reflect the ancestral diets of our dogs and cats’ evolutionary predecessors, but veterinarians who I spoke with also questioned this logic.
For one thing, our pets’ wild cousins aren’t very healthy. “People believe nature is better,” Larsen said, but “wild animals don’t live as long and don’t lead very healthy lives.”
For dogs, we know that they differ genetically from wolves in their ability to digest starches. “Dogs are not wolves,” said Robert Wayne, a dog geneticist at UCLA. “They have adapted to human food.” Research in Wayne’s lab showed that most wolves carry two copies of a gene involved in starch digestion, while dogs have between 3 and 29 copies. According to Heinze, the average dog can easily manage 50 percent of their diet in the form of carbohydrates.
For cats, this argument makes a little more sense. Cats are carnivores rather than omnivores, so they have higher protein needs than dogs, but “cats can digest and use carbohydrates very well,” said Andrea Fascetti, a veterinary nutritionist at the veterinary school of the University of California at Davis.
Many grain-free pet foods are made from potato or lentil starch and may contain more fat. If you reduce grains but increase calories, your pet will gain weight, Heinze said.
Dogs and cats also have a radically different lifestyle than wolves or tigers. Pets are almost always sterilized, which in itself is a risk factor for obesity. And most live indoors or in enclosures, so their energy needs are greatly reduced.
In nature, wolves and feline predators eat the hair, bones and cartilage of their prey, not just the meat. For pet owners who choose to feed their pets an all-meat diet, it’s essential to add supplements to ensure their pet isn’t deficient in key nutrients such as calcium, Fascetti said. And there is the environmental impact to consider: Pets consume a quarter of all animal calories in the United States.
Experts particularly warn against feeding animals raw meat. “It’s not uncommon to find things like salmonella, E. coli and listeria in raw meat,” Larsen said. Many microbes are present in our livestock systems and, unlike when an animal hunts in the wild, there are many opportunities for bacteria to contaminate meat between the time an animal is slaughtered and where it arrives in our kitchens.
Although eating contaminated meat does not make animals sick, it poses a health risk to pet owners and their children who handle animal food and waste. THE Centers for Disaster Control and Prevention and the Food and Drug Administration both warn against feeding raw meat to your pets, and “I really can’t recommend it, because it’s not safe for the whole family,” Heinze said.
But what about all those benefits we hear about from eating raw foods, like a shiny coat and less frequent bowel movements? “I can’t tell you how many customers send me poop pictures,” Larsen said. But changes in a pet’s grooming habits have nothing to do with whether its food is raw.
Raw diets tend to be lower in fiber, and high fiber likely leads to bulkier stools. But we don’t know whether stool quality and quantity correlate with health, Fascetti said. And that shiny coat is likely due to its high fat content, Heinze said.
If pet owners wish to formulate their own diet, they should work with their veterinarian and a certified nutritionist. If you feed your pet a balanced diet, such as in a commercial food, obesity is the biggest nutritional problem pet owners should worry about, Heinze said.
We want our pets to enjoy what they eat, which is why many foods, especially treats, are formulated to be high in fat, Larsen said. Most people don’t realize that a milk bone has about as many calories as a candy bar, Lock said.
I know the struggle. My own husky mix looks at me with her big brown eyes and licks the window every time she wants food. I’ve taken to calling the dental chews I buy him “guilt” because I can’t help but give him one every time I leave.
But studies have shown that feeding dogs to maintain a lean body weight has very positive effects on their overall health and may even increase lifespan. This is also the case in mice and ratsand “we think these results also apply to cats,” Fascetti said.
There is no magic diet for every animal. These experts strongly recommend working with your veterinarian to find a diet that is right for you and your pet. When it comes to navigating marketing claims in the pet food aisle, Lock suggests finding a company that employs a veterinary nutritionist and conducts feeding trials. Try not to get too hung up on “the no list,” Heinze said. “Claims like gluten-free, grain-free, and soy-free generally don’t mean any science.”
Correction: This article originally stated that “Taste of the Wild” was produced by Chewy. The company distributes but does not produce pet food.
