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The pet food industry offers diets for every stage of a cat’s life, from formula for newborn kittens to senior cat food. The kitten milk-replacement is one thing, but what’s the difference between solid food for kittens, adults, and seniors? And what about the cat food that says it’s for “all life stages”? Today we look at the difference between diets for the various life stages and what really matters for your cat.
Kitten Food
Before doing this research, I knew there was at least one difference between kitten food and any other cat food. I took Joon in when she was about four months old, and I was living with a roommate that already had a cat. Domino is a gorgeous tuxedo cat with spooky yellow eyes, and she was quite pudgy. My roommate had to put her on a diet, and Domino was not a fan. She kept eating Joon’s food, which Joon was too busy playing to care about. My vet told me I should be careful to keep her from doing this, because kitten food is high in calories.
It makes sense, doesn’t it? Kittens are still growing rapidly, and as they get older they use up a lot of energy playing as well. In fact, kittens may need up to three times as many calories as an adult cat each day (1, 2, 3)! And they have higher protein requirements than adults, as well, needing to get about 30% of all that energy from protein (2). Most of the rest of the calories need to come from fat to ensure that they get enough essential fatty acids for proper development (1). Kittens need lots of vitamins and minerals as well. Basically, like all babies, kittens need lots of nutrients in their diet so they can grow up big and strong. So kitten food is made more nutrient-dense than adult food.
The Association of American Feed Control Officials (AAFCO) requires kitten food to be at least 30% protein and 9% fat on a dry matter basis (4). A survey of 212 adult and kitten foods by IdleCat found that kitten foods actually averaged 40.77% protein for kibble and 49.11% protein for canned food (3). The fat content was a little closer to the minimum recommendation, but for both kinds of food was more than 21% higher than the average fat content of the adult foods (3). Carbohydrate and fiber content were lower to compensate (3). Vitamins and minerals weren’t measured in that survey, but in a well-balanced kitten food they should be present in higher amounts as well.
Kitten food is also made to be easier for small mouths with developing teeth to eat. Canned kitten diets are typically softer, and the kibble comes in smaller pieces (1). However, the nutritional differences are what is most likely to impact a cat’s health. Adult cat food is usually not nutrient-dense enough for kittens, although it will do temporarily in a pinch (5). Conversely, as my vet told me, kitten food can cause adult cats to gain too much weight. Depending on the nutrients included, the extra vitamins and minerals could even cause toxicity in an adult cat (1). A few bites here or there is unlikely to cause anybody any harm–Domino is certainly none the worse for it–but kittens need kitten food and adults should be kept away from it as best we can.
Cats are considered kittens up to one year of age, with the exception of some large breeds. Maine Coons do not reach maturity for up to two years. If you are unsure how long to keep feeding your cat a kitten diet, check with your veterinarian.
Adult Cat Food
Adult cat foods are formulated to maintain a grown cat’s weight and health. Growth and development never completely stop. All organisms continue to make new cells, repair damaged tissues, and progress through their life cycle as long as they live. However, an adult cat uses much less energy than a kitten to do these things, so they need far fewer calories and other nutrients relative to their body weight. This is reflected in the nutritive content of adult cat food.
The AAFCO divides their standards for cat food into two categories: “growth and reproduction,” for kittens and pregnant or lactating queens, and “adult maintenance” for the average, older, and sterilized adult cat (6). The minimum protein content for adult maintenance is 4% lower than the recommendation for kittens and queens. The fat minimum is the same, but 5 out of 12 mineral recommendations are lower for adults, as well as Vitamin A (4). These minerals and vitamin can cause toxicity in excess, which is more likely in adult cats who use less of the nutrients than a growing kitten or a queen who is growing kittens.
Cats are typically considered “adults” from the age of one year to seven years, although this varies some by breed and individual cat (7). Those of us with rescue cats often don’t know exactly how old they are, so you and your vet may have to play it by ear to decide when the time seems right to start treating your cat like a senior.
Senior Cat Food
In the United States, the AAFCO is the government body responsible for licensing pet food, and as previously indicated, they don’t issue standards for senior cat food. The consequence of this is that senior cat food is very similar to adult cat food, with some slight modifications that won’t color outside the AAFCO adult cat food guidelines (8). Whether this is a bad thing or not is hard to say. A lot remains unknown about the needs of senior cats. Due to lack of research, many of the decisions made about how to feed senior pets have been made based on what is known about aging humans (9). Even so, there have been improvements in senior cat diets over the years.
But some cats may not need to go on a senior diet at all, or not until much later in life. If an older cat is keeping up their body weight and muscle condition on their adult diet, there’s no need to change them to a senior diet (8). If a senior kitty begins to gain or lose weight or lose muscle mass and no associated health problem is found, a change in diet may be in order (8). However, senior cat diets can be pretty different from one another. Of course, cats with age-related health problems may be put on a diet specific to their needs. If your vet recommends just plain senior cat food, however, the variability in formulations can be overwhelming.
It used to be the case that senior cat food was low protein, low fat, and high fiber (8), and the myth that senior cats need a diet low in protein still persists. Some health conditions may call for a low-protein diet, but a normal senior cat may suffer greater muscle loss with less protein (9).
Whether or not senior cats need more protein than adult cats is still unclear, however, and may depend upon the individual cat. If they are notably losing muscle mass, then a high-protein senior diet may be the solution (10). There are still senior diets made with low amounts of protein, all the way to those with enhanced protein, so it pays to check the label. Remember that it’s the dry weight of the nutrients that you need to compare, as the amounts on pet food labels are given in minimum and maximum percentages instead of absolute quantities. Check out this page for a rundown of how that math works.
Senior formulas may be low-calorie, hence the traditional wisdom of making them high-fiber, and for some cats this is appropriate. Generally, cats tend to have progressively slower metabolisms up to eleven years of age and are prone to obesity during middle age, around years six to eight (11). Once they get older than that, they often start to lose weight and may need high calorie diets (11).
Sometimes a vet may actually put a senior cat on a kitten diet if weight loss is a major issue, simply to get enough calories into them (8). In milder cases, a more calorie-dense senior food may be the way to go. If your cat has the opposite problem, well, low-calorie is where it’s at. Both obesity and being underweight can cause significant health problems or be symptoms of them, so keep a close eye on the body condition of older cats. If something changes, always have a vet check for disease before trying to treat the problem with diet alone.
There are other variables as well, such as dietary phosphorous and sodium, which sometimes matter for senior cats if they have certain health problems (9). If your cat has any health issues but they don’t require a medical diet, ask your veterinarian if there is anything you should be on the lookout for when choosing their food.
All Life Stages Cat Food
In order for a pet food to claim that it is “complete and balanced” for all life stages, it must meet the standards set by the AAFCO for both the growth and reproduction and adult maintenance stages. Because the minimums for certain nutrients are higher in the growth/reproduction stage, and there are only a few maximums, “all life stages” food may be too nutrient-dense for some adult cats (12). The food has to have enough nutrients for every stage of life, so it makes sense that what you end up with is more like the food intended for kittens and queens. They have higher nutrient requirements.
Opinions are divided, but I found that veterinarians seemed most inclined to think that food for all life stages was really not appropriate for adult or senior cats (12, 13). Pet food companies had the more mixed advice. Personally, I think all life stages food is great for keeping on hand if you find a stray cat or kitten you need to assist, as you never know what age they might be, and the extra nutrients are probably not a bad idea. It’s not what I would feed my cats at home, though.
Works Cited
- Paretts, S. (n.d.). What is the difference between kitten and cat food? The Nest. https://pets.thenest.com/difference-between-kitten-cat-food-6832.html
- ASPCA. (n.d.). Cat nutrition tips. link here
- John, B. (2019, November 19). Kitten food vs. adult cat food: What are the differences? IdleCat. https://theidlecat.com/kitten-food-differences/
- Association of American Feed Control Officials. (2014). AAFCO methods for substantiating nutritional adequacy of dog and cat foods: Proposed revisions edited per comments for 2014 official publication. PDF
- Syufy, F. (2019, November 4). How to choose the best kitten food. The Spruce Pets. https://www.thesprucepets.com/choosing-best-kitten-food-552267
- US Food and Drug Administration. (2020, February 28). “Complete and balanced” pet food. link here
- Chewy Pet Central. (2019, November 13). Cat food for all ages: How (and what) to feed your cat during every stage of life. https://petcentral.chewy.com/ages-stages-cat-food/
- Chewy Pet Central. (2019, December 10). The best senior cat food: A guide to feeding your older cat. https://petcentral.chewy.com/best-senior-cat-food/
- Freeman, L.M., Linder, D.E., and Heinze, C.R. (2016, March 8). When should I switch my pet to a senior diet? Tufts Clinical Nutrition Service. https://vetnutrition.tufts.edu/2016/03/when-should-i-switch-my-pet-to-a-senior-diet/
- Pittari, J., et al. (2009). American Association of Feline Practitioners: Senior care guidelines. Journal of Feline Medicine and Surgery, 11(9), 763-778. https://doi.org/10.1016/j.jfms.2009.07.011
- PetCoach. (n.d.). Do senior cats have different nutritional needs? https://www.petcoach.co/article/nutritional-needs-of-senior-cats/
- Coates, J. (2014, April 25). Are life stage dog foods credible? PetMD. https://www.petmd.com/blogs/nutritionnuggets/dr-coates/2014/april/debate-over-all-life-stage-dog-foods-31604
- Rock Veterinary Clinic. (n.d.). Understanding pet food labels. https://www.rockvetclinic.org/post/understanding-pet-food-labels.html
Published July 26th, 2020
Updated November 1st, 2020
