Not quite sure what the point is of this?
Cockroach physiology would have minimal, if any, translation over to human physiology. They are in a totally different phylum.
The only thing that is of worth here is that a diet of one macronutrient is conducive to what these researchers are calling "poor health." I am not exactly falling out of my chair. Even the point on sexual maturation's link to diet has been proven over and over again in animals ranging from anthropoids to rats to humans.
The concept of early life diet causing differences in behavior in later life is something that is also being explored in humans with a pretty high degree of success.
I guess my point is that this isn't really new -- but i guess if you have never seen any of the similar studies before then this is interesting. However, this report is less compelling than the data that exists on humans and animals closer to our species.