
It’s a question that you might ask: “Is it okay for kittens to eat adult cat food and adult cats to eat kitten food?”
The short answer is, No. If an adult cat eats food made for kittens it wouldn’t be much of a problem for the reasons stated below. However, if a kitten consistently eats food made for adult cats, over a period of time, it could lead to a problem in respect of the kitten’s health and development.
Growth formula food for kittens
The reason is that kittens need a growth formula food for the simple reason that by the time they are nine months of age they’re pretty well full-grown and sexually mature. It takes humans 13 years to reach this stage and accordingly it takes a lot of nutrition to support kitten growth at this rate.
Ten-week-old kittens require about two times as much protein and 50% more calories per pound in weight than adult cats. At the age of 12 weeks a kitten needs three times the amount of energy input in terms of food than an adult cat.
Even at the age of six months a kitten needs 25% more nutrition than an adult cat. In general terms a kitten’s diet needs to be high in protein and calories. This is vital in terms of general health and developmental issues.

A kitten uses protein in her food to build muscles and protein plays an important role in the growth of her coat and in her circulation. Fat in her diet will help supply the energy which is burnt up in play. Fat is the most concentrated source of calories. Vitamin A is crucial to the growth of a kitten and for metabolism. Vitamins and minerals are important in general as is water which is vital for the health of the cat’s skin and cells.
It is said that a kitten can feed freely because it is almost impossible to overfeed a kitten. The experts say that as a general rule kittens should be fed as much as they can eat.
Early neutering, which is a current trend, decreases metabolism in a kitten by at least 25%. This should affect a kitten’s diet. Of course your veterinarian will be able to advise about correct feeding practices.
Kittens need to gain about 1 pound a month until they reach about 8-10 months of age.
Adult cats – less of a problem eating kitten food
If an adult cat eats kitten food he or she will be consuming food which is too high in calories. I would expect that this would not be a major issue but it may lead to weight gain.
I have fed sick and very elderly cats kitten food before now, when they needed desperately needed extra calories. As these foods are higher protein, I have not used it long term in cats who have compromised kidneys. If a cat is living their last days or desperately ill, then it’s a case of them having whatever they want to eat.
Yes I agree. And when I see a cat food that says “Cat & Kitten food”, I ask “Really?”. No qualifications or further explanation necessary, huh?