The hidden reason processed pet foods are so addictive

A hand in a pocket, the opening of a cabinet door, or simply a carelessly spoken phrase – "meal" – may be the indication. You're stumbling over a pet who is eagerly anticipating a piece of... dull-brown dry pellets before you realize it. What is it about these mystery morsels that makes them taste as good as grilled chicken, wild salmon, or fresh herb bundles?

Take, for example, my roommate, a little black rabbit. He may be found sitting intently with his paws on his empty food dish for a substantial chunk of every day, anticipating his next mouthful of kibble - even though it looks like his droppings and smells as unappealing. He used to have an automated dispenser with a timer, but he learned how to hurl it across the room to get to the contents before the timer ran out. Whatever luxuries I put in front of him — home-grown parsley, soft-cut hay, fresh carrot tops, organic kale – he prefers commercial pet food.

This does not appear to be rare. The cat who suffers a daily panic episode when it realizes it has eaten all of its pellets and the pragmatic German shepherd discovered lugging a bag of dog food through the streets of Houston during Hurricane Harvey are just two examples of creatures whose brains are mostly focused with chow.

This addicting characteristic is, in fact, meticulously manufactured. Big Pet Food is a multibillion-dollar company that spends a lot of money on research into "palatants" — additives that make our dogs desire to eat it. And the effort to create the most delectable pet food has led to some startling discoveries, ranging from potently odorous compounds frequently found in decaying flesh to an additive typically put to potatoes to prevent them from discoloring. "Big [pet food] corporations have vast departments that develop palatants," says Darren Logan, chief of research at Mars Petcare's Waltham Petcare Science Institute. "We manufacture them for dogs the same way we create them for humans." 

Dogs from the upper crust

James Spratt, an ambitious lightning-rod dealer from the US state of Ohio, produced the first pet food in 1860. According to legend, he was in England on business and was looking out over Liverpool's docks one day when he observed stray dogs eating leftover hardtack biscuits. 

Firstly, hardtack were famously unappealing – loathed by generations of the soldiers and sailors who ate them, these simple slabs of baked flour and water were tougher than wood and sometimes hard enough to break your teeth. Their nicknames included "sheet iron" and "worm castles", the latter because of the high proportion that were infested with maggots and weevils. The oldest piece of surviving hardtack was baked just nine years before Spratt's dock visit, and still looks suspiciously well-preserved 170 years later.

Before, it wasn't uncommon for people to check what their pets wanted to eat. For many years, pets were fed the same food as humans. This is because they expected to be fed the same food. Until that moment, we didn't know what our pets wanted to eat. For as long as we have been keeping them, they have been fed the same food as Since they are so well-adapted to this diet, they were brought to the Antarctic by the British Antarctic Survey in 1945. 

Dogs that were lucky enough to be fed were typically given scraps or gruel. Other exotic animals were also fed everyday human food. Spratt had always been a passionate animal lover. So when he came across a recipe for a strange treat that promised to meet the nutritional needs of dogs, he knew he had to develop it. The rise of pet ownership coincided with the cultural revolution that took place after the introduction of the Meat Fibrine Dog Cake. This product was marketed as a luxury food for pets.

Disgusting smells

The company's slogan was "Dog's Delight". Ratt's eventually branched out into cat food. The science of pet food nutrition still had some way to go yet. Special kibble for pets can be bought for almost any kind of animal. They usually contain various kinds of base carbohydrate, protein, and fats, as well as various additives and preservatives.

These components are made into a paste and "extruded" into a dry pet food by heating them and pressing them through a plate with holes in it, resulting in an aerated product that matches the shape of the holes. It's the same procedure as making puffed snack items, with flavorings added last — in the case of pet food, they're either sprayed on or sprinkled on.

There isn't much of a link between a pet food's nutritional value and its innate delectability. That's because in the United States, the European Union, and many other areas of the globe, a product must fulfill specific nutritional requirements in order to be labeled "complete" - meaning it contains everything the body need to stay healthy. These specify permissible ranges for most ingredients, ensuring that makers can't simply pile on the sugar and fat to make it appealing.

"All pet foods are the same to me as a nutritionist," says Marion Nestle, emerita professor of nutrition, food studies, and public health at New York University.

Many animals rely on scent to navigate their environment, and this is frequently the sense that is targeted. Cats have 67 million, rabbits have 100 million, and dogs have roughly 220 million olfactory receptors, whilst human noses have roughly 50 million. Their sense of taste, on the other hand, is less discerning than ours — our high density of taste receptors is considered to have developed to help humans cope with our varied omnivorous meals. The problem is that appealing to animals who find the smells of roadkill, dirty socks, and vomit totally enticing – as many carnivorous pets do – while not making their human partners violently ill, is incredibly difficult. "There is a tiny paradox there," Logan adds, "since the fragrances that cats, but also dogs, appear to enjoy are frequently the polar opposites of what people enjoy." The trouble is that appealing to animals who find the scents of roadkill, soiled socks, and vomit irresistible – as many carnivorous pets do – while not making their human companions violently ill is quite tough. "There's a small paradox there," Logan continues, "because the scents that cats, but also dogs, seem to appreciate are usually the polar opposites of what people prefer."

Putrescine and cadaverine, for example, are colorless compounds created naturally when proteins are broken down. They're mostly to blame for the repulsive odor of rotting meat, and cats adore them. While their levels in human food are occasionally strictly controlled to ensure the freshness and safety of meat, they're frequently intentionally added to cat and dog food, either as offal extracts or lab-made additions. Irresistible fragrances like mint and oregano are occasionally supplied in the form of concentrates to inherently vegan animals like rabbits and guinea pigs.

Cuisine with a Japanese influence

Other findings, on the other hand, are arguably more startling. Heptanal, nonanal, and octanal, all of which have strong, fruity odors, were discovered in a recent study as nine volatile chemicals in typical pet food flavorings that are connected to how tasty they are to dogs. Taste, on the other hand, is vital, and carnivorous pets' preferences aren't all that far from ours. The intriguing "hydrolysed protein," which is made by breaking down the lengthy strands of proteins into their component amino acids, commonly using enzymes or hydrochloric acid, is one of the most common additions in human diet.

It has a flavor comparable to meat or vegetable stock, and it frequently contains MSG, which is formed as a by-product of the same reaction and is responsible for the savory flavor of tomatoes, cheese, and Iberico ham. Though hydrolyzed proteins are manufactured artificially, the process is comparable to what occurs when food is cooked for a lengthy time – it's a form of pre-digestion that is considered to contribute to the appealing aroma of many kibble brands. "Kitten palatability is quite comparable to Japanese or Asian food, where umami and another flavor modality called kokumi are highly important," Logan explains. After sweetness, saltiness, bitterness, sourness, and umami, kokumi was found in Japan in 1989 and has been postulated as the sixth flavor in humans. It's regarded as a texture that adds richness and "thickness" to dishes rather than a flavor. Unlike the others, kokumi has yet to be connected to a precise collection of components, however scallops, soy sauce, shrimp paste, yeast, and beer are foods that evoke this sensory sensation.

The sixth taste is supposed to be particularly appealing to carnivorous animals, who may perceive it through calcium-detecting receptors in their mouths. And, as you might guess, pet food manufacturers have already begun to target it with chemical combinations that enhance flavor. The sixth taste is supposed to be particularly appealing to carnivorous animals, who may perceive it through calcium-detecting receptors in their mouths. And, as you might guess, pet food manufacturers have already begun to target it with chemical combinations that enhance flavor. However, there are several flavors that are never found in pet meals. Most wild predatory animals, for example, lack taste receptors for sugar or carbs. Domestic cats, on the other hand, have only been around for around 4,300 years, unlike dogs, who have lived with humans for up to 40,000 years and feasted on our trash.

Vegan animals, on the other hand, prefer sweeter pet food since they eat only vegetable stuff, which is frequently high in fiber and carbs. Finally, no list of palatants would be complete without pyrophosphate, sometimes known as "cat crack" in Popular Science. This ubiquitous food ingredient has a variety of functions in human food, including avoiding darkening of potato goods after cooking - none of which entail boosting its taste. Cats, on the other hand, go crazy over it, presumably because it enhances the flavor of amino acids. Pet food businesses have gotten so skilled at manufacturing tasty food for pets that they're running into a problem: it's nearly too good. "Today's threat for cats and dogs is the same as it is for people: overconsumption," says Andrew Knight, a University of Winchester professor of animal welfare and ethics.

In the industrialized world, pet obesity is on the rise, with one study of veterinary experts at a London vet show estimating that 51 percent of dogs, 44 percent of cats, and 29 percent of small animals are overweight or obese.

According to Logan, this is due to humans falling to their pets' begging gazes rather than the way pet food is designed. "We make pet food pleasant because if they don't consume all of the food that we offer them, it won't satisfy their nutritional demands," he explains. "The main issue is that owners overfeed their dogs since they can't open the packages themselves." However, there is a silver lining. There are growing worries regarding pet food's environmental effect; in 2009, two New Zealand scientists assessed that owning a dog costs the Earth nearly twice as much as owning a medium-sized SUV. However, there is a silver lining. There are growing worries regarding pet food's environmental effect; in 2009, two New Zealand scientists assessed that owning a dog costs the Earth nearly twice as much as owning a medium-sized SUV.

This is when palatants enter the picture. Pet meals derived from more sustainable sources such as insects or soya are often just as palatable to carnivorous pets as the actual thing, because most pet feeds consist of a very bland foundation that is spruced up with delightful flavourings and aromas. (However, cats cannot be fed a meat-free diet.) "According to this fairly large-scale study that we just did, the animals on vegan pet foods seem to be equally as happy as the animals on meat pet foods," adds Knight, who is optimistic about the future possibilities of vegan pet foods. "There is widespread realization that the need to be more sustainable will have a significant influence on the pet food industry," says Logan, who adds that the pet food firm where he works just launched its own line of insect-based pet food. So, why are our pets so addicted to pet food? Because it was designed to be that way. Our pets, like us, find it difficult to say no to the delectable food we've created.