Cat Food Nutrients & Ingredient Quality
Your cat’s specific caloric and nutrient needs will vary widely based on age, size, breed, activity level, overall health and other factors. While all commercially-produced cat foods have to meet benchmarks for nutrients to be labeled as “complete and balanced foods” by the AAFCO (American Association of Feed Control Officials), it is important to understand that more is not necessarily better.
In some cases, excess nutrients are harmlessly expelled in the cat’s waste (stool). In other cases, an overabundance of a specific nutrient can cause serious problems if your cat has an underlying medical condition like kidney disease. A veterinary nutritionist understands how to balance nutrients in a recipe to promote good health.
When comparing nutrient information on a commercial package, it is also important to take into consideration moisture content or measure by serving size. A dry food label may show that it has higher protein per ounce than a wet or fresh food, for example, and that may be true. However, if you compare on a dry-measure basis (remove the moisture content from both foods) the dry food may actually have less protein per weight. Ideally, nutrients should be compared on a caloric basis, and typically these are expressed by the weight of nutrient per 1000 calories. This allows you to directly compare any two diets, whereas both the as fed (label) and dry matter basis do not.
Fresh (& Homemade)
Whether made in a home or commercial kitchen, fresh cat foods are often made from whole cuts of meat, vegetables and are often supplemented with beneficial oils and nutrients. Fresh foods are usually lightly cooked, which can help increase how well digested the proteins and carbohydrates are in the food. And, for cats of course, the carbs are typically minimal to match the amount naturally in prey since they are true carnivores.
Fresh foods tend to have little to no added fiber that adds bulk and structure to other foods. This means that your cat’s digestive system can break down and use more of the food itself, with less waste. Many fresh foods have a far shorter list of ingredients, especially when compared to more highly-processed dry and wet foods. If you like knowing exactly what you are feeding your cat, an ingredient list made primarily of fresh meats could be preferable.
Meanwhile, cat food made at home may seem appealing because you are in control of the ingredients, and it certainly feels nice to put in the effort to make something from scratch for our pets. But far too often, recipes shared by friends or found online are missing important nutrients your cat needs, or fail to have various nutrients in the right ratio to promote good overall health. A nutrient imbalance can lead to serious health issues and expensive vet bills. We recommend that you only use recipes from a reputable veterinary nutritionist (as noted earlier, an expensive process), and check in often with your vet to ensure your cat is getting all the nutrients they need to stay healthy.
Many dry foods, especially more affordable options, are created to meet only slightly more than the minimum nutrient content required by the AAFCO, say for protein as an example. As noted, while more of a given nutrient is not always better, some cats may benefit from additional protein (like senior pets), calcium, or other nutrients depending on their individual health needs, life stage, and activity level.
The quality of the proteins in dry foods often varies based on cost. While expensive, specialty foods could theoretically use whole cuts of higher-quality muscle, many foods use the meat leftover from human food processing; cheaper and mid-grade foods may use meals with lower protein digestibility. If you see “chicken” in the name of the food, that does not necessarily mean it is made with whole chicken breasts or thighs for example. AAFCO has a great breakdown of the differences between animal ingredients, such as meat, meat by-products, meat meal, animal by-product meal, and more.
Some dry foods include high amounts of insoluble fiber (powdered cellulose or grain hulls) to add bulk to the food, and in some cases to change how quickly food moves through the cat’s digestive system. These ingredients offer no direct nutritional value to your cat.
If you tend to avoid preservative-laden foods for yourself and your family, you should consider some dry kibble can include synthetic preservatives like ethoxyquin, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). These preservatives tend to prevent the fat in the food from becoming rancid, allowing the sale of larger bags of food that last longer in retail stores and your home. While no studies have proven that these preservatives cause problems with pet health, many pet parents want to avoid them (or at least limit them) out of caution.
Like the more affordable dry food options, cheaper commercial wet foods will meet the minimum AAFCO nutrient guidelines, but may not include higher levels of nutrients that could be beneficial to your cat. More expensive options and therapeutic diets often have nutrient content designed for specific life stages or health needs.
Do not trust your eye to gauge quality when looking at wet foods. While some foods incorporate whole cuts of meat, many are made from meat by-products, meat meal, animal byproduct meal and other ingredients that are pressed and shaped into chunks that only resemble whole cuts of meat, often with unknown digestibility based on the information on the label. This is designed to entice pet parents, not cats themselves.
Canned cat food usually does not contain significant artificial or natural preservatives, as the canning process itself is a fairly effective preservation technique. Be sure to look at the “best by” date on canned food and do not serve any food that is past its date. In some cases, canned food can last for years if properly stored, though we do not always have data to understand whether such long-term storage affects the nutrient benefit of the food itself.