Good. Age really isn't a huge factor in food. I'd say it's probably one of the least important factors. Most of the highest-quality kibbles are "all life stages" kibbles and are great for all life stages. The one exception I'd have is puppies - some of the all-life-stages aren't the best for puppies (I think Taste of the Wild is one of them, actually) if I recall because of the calcium and phosphorus levels...I've have to go look it up to be sure. But there are still many all-life-stages foods that are suitable for puppies.
Honestly, I think having 346785243 different formulas from one brand is a marketing ploy more than anything else. Hills comes to mind - the entire alphabet of prescription diets, then small, medium, and large breed formulas of puppy, adult, senior and light, different kibble size options for each of those foods, with hairball or without hairball control for cats, oral care, joint care, etc. Then there's also the brands that have breed-specific foods...lab food, yorkie food, GSD food, boxer food, bulldog food, etc. They're really not necessary in my opinion, just another way to make money off of a corn-based, low-quality, heavily advertised food.
* Spectrum steps off soapbox
Topic: Many Pet Owners Don't Consider Pets' Age When Buying Food (Read 172 times)