Only a couple of health claims are allowed on cat food labels, including one for urinary health and one for hairballs. All other health claims are illegal (although you can say a food cleans teeth). So why do so many cat foods have claims like “promotes brain development” and “helps muscle function”?
The reason is that statements like these are not considered health claims but, rather, structure/function claims.
Here’s the distinction. A health claim ties a specific food to a specific outcome: feed this food, and your cat’s urinary tract will be protected.
A structure/function claim, on the other hand, masquerades as a claim but is actually a statement that can be made for any food. What cat food wouldn’t support brain development in a kitten or help muscle function? After all, such phrases do not claim that the food will help prevent, cure, or treat a disease. They’re just saying that eating — ingesting calories — helps the brain, helps the muscles. It’s true. The brain and muscles can’t function without food, so such statements slip through in a health claims loophole.
Don’t be fooled. Recognize structure/function claims for what they are: marketing ploys.