As I understand it the reason you have acne is because of a hormonal imbalance. Your hormones are causing your skin glans to produce to much oil. This oil rises to the surface of your skin and may get dirt and bacteria from the air mixed in it. This then proceeds to an infection and you have a zit. Now diet, nutrition, and lifestyle does propagate the occurence but the actual cause starts with your hormones. Some women are able to fight the battle by taking the pill, men are not that fortunate.
All the acne drugs on the market just cures the symptoms i.e. the acne it self...to date medical science has not been able to cure the cause i.e. your hormonal imbalance...so for now all acne suffers have to maintain a health diet, and lifestyle...and also use some sort of acne medicine to cure the zits.
I have researched acne for a number of years, and I do know that there are many myths surrounding the cause of acne.