Are kibble + canned cat food ultra processed?

Ultra-processed foods, or UPFs, is a buzzword that has gained popularity in recent years in human nutrition. But what exactly are they, how can one spot them, and do they apply to pet food? This article will help you understand why this is a critical issue that needs attention in the pet food community.

The term UPF was coined in 2009 by a group of researchers from Brazil to define (human) foods that have very unique characteristics. Precisely, UPFs are defined as “ready-to-eat industrially formulated products that are made mostly or entirely from substances derived from foods and additives, with little if any intact unprocessed or minimally processed ingredients.” They are foods that one cannot whip up in the kitchen, but must be manufactured only in a factory through processes like extrusion, moulding, and hydrogenation.

An easy way to spot a UPF is to look at its list of ingredients. UPF tends to have a long list of ingredients that make you hiss in confusion. To begin with, they likely include food derivatives, i.e. compounds that are extracted from foods and are no longer intact foods, such as protein isolate, hydrogenated oil, or high-fructose corn syrup. Often, they also include food additives such as non-caloric sweeteners, preservatives, emulsifiers, food dyes, flavours, bulking agents, and anti-caking agents. 

To give you an idea, think of jacket potatoes and roasted chicken — they are not ultra-processed. But BBQ-flavoured crisps and chicken nuggets? They are totally UPFs. If you can’t find the ingredients to make it in your own kitchen, it’s likely a UPF.

Having consensus on a UPF definition is very useful, because every health professional across the world can now recognise what is and what is not a UPF. There’s a growing body of research showing the negative impact of UPF on our health. People who consume higher intakes of UPF are at higher risks of developing obesity, heart disease, cancer, diabetes, Alzheimer’s disease, depression, and more. The list is growing each day as more research rolls in.

At the moment we don’t exactly know why UPFs are so bad for us, but scientists have some theories. UPFs are generally higher in free sugars and total fats, while being lower in fibre, vitamins, and minerals, and bioactive compounds that are beneficial to our health. That simply means UPFs are less nutritious per calorie consumed. They also seem to have a lower satiating effect, and people may need to eat more calories to curb that craving, which can lead to obesity. Eating UPFs also leads to higher cholesterol, increased inflammation, worsened control of sugar level in the blood, and gut microbiome dysbiosis (an imbalance in the community of microorganisms that live in our intestine).

There’s probably no single right answer for their deleterious effects, but UPFs may act through multiple pathways to create a perfect storm for poor health.

So far, we have been talking about our (human) food. What about the food of our beloved whiskered companions? If we look at the human UPF definition, one may think that kibble and canned food also fit this definition purr-fectly. 

Cooking through extreme processing - ✔ 

The dough in traditional kibbles is a mixture of ingredients and cooked at extreme temperatures. It is then pushed through an extruder into certain shapes (aka extrusion) and dried. For canned food, the mixture is often first cooked to gelatinise the starch (rearranging of the scratch molecules to form a viscous paste with water) and then filled into cans. The cans are then cooked again at high temperature, this time to sterilise and kill off pathogenic bacteria. The cooking and drying under extreme conditions have an impact on nutrient loss.

Having a long list of unrecognisable ingredients - ✔ 

Kibble and canned food may use cheaper, lower-quality ingredients that are not allowed to be used in human food. Things like animal byproducts, for example. Food derivatives such as protein isolate or hydrolysed proteins are also common.

Using food additives like preservatives, emulsifiers, flavours - ✔ 

These additives are necessary to prolong shelf life, cover unpleasant flavours/smells, and increase product’s attractiveness to your kitty.

So, we can call kibble and canned food UPFs, right? Well, the answer’s more complicated than a ball of yarn. Human UPFs are often characterised by their low amounts of vitamins and minerals, meanwhile commercial pet foods are tightly regulated by the officials (such as the FEDIAF in the UK and AAFCO in the US) to be nutritionally complete — meaning that they must provide all the essential nutrients needed for growth or maintenance. 

That said, kibble and canned cat food don't fully align with the UPF definition, as commercial pet foods are formulated to be nutritionally complete, whereas the UPF concept was originally developed with human foods in mind.

Because humans and cats have different physiology and nutrient requirements, and because highly processed pet food doesn’t perfectly match the human UPF definition, right now we can’t say with 100% certainty that pet food will have the same negative effects as human UPFs. However, there is some evidence suggesting that highly processed cat foods are perhaps bad for our feline friends. 

For example, kibble is consistently associated with a high risk of obesity in cats. There are also concerns around food additives and heavy metal in commercial kibble and canned diets. And because they are cooked at high temperatures, advanced glycation end products, or AGEs, are formed in these foods. AGEs are products of chemical reactions between carbohydrates and proteins in food that are characterised to be bad for health. In humans and dogs, increased consumption of AGEs increased their serum levels and inflammation, but no research has been done yet in cats.

On the other hand, many kibble and canned foods are formulated as therapeutic diets to support weight control, renal health, dental health, and gastrointestinal health. Veterinarians prescribe them and they have rigorous scientific studies to back up the claims. However, this is not quite a fair fight for the less-processed foods — studies often compare the reformulated diet with the regular diet, both of which are the same type of food. It’s like saying that a bag of crisps reformulated to be low-sodium and low-fat is healthier than a bag of regular crisps, while a better comparison would be to a less processed, boiled potato.

As alternatives to kibble and canned food, less-processed food options have been making their way into the food aisle. You may have seen raw meat-based food, fresh food, dehydrated food, and freeze-dried food for cats. Among them, KatKin is the first fresh cat food brand in the UK formulated by veterinary nutritionists to be nutritionally complete, using human-quality meats, gently cooked, and frozen for freshness. We believe that cats did not evolve to eat kibble or canned food.

But largely, the volume of research into these food options are still much smaller than the traditional kibble and canned food. Most of the research in veterinary science is funded by the big kibbles, who don’t care much about the less-processed options.

We want to point out the critical lack of research in the topic of food processing and the health of cats. There is so much we don’t know, especially how less-processed food options compare to traditional kibble and canned foods. Are they healthier? At KatKin, we believe so, based on our higher quality of ingredients, lower processing level, and numerous stories we hear from our customers.