Yes, definately, especially high fat diets which regulate hormone levels
Also an increased metabolism makes your body generate more heat, which in summer means you produce more oil
Do you use Probiotics?
Also get hold of some zinc seperate from your multivits
Test levels hit there peak during summer then drop to normal levels again during winter
There is an article about this at T-MAG
Its pretty interesting, check it out
I think it is called The Big T