Here is a challenge for everyone who claims to have found a connection between reduced acne and $X, where $X is whatever: sugar, carbs, exercise, sun light, nose picking, masturbation, sex, chocolate, stress, soda, tv, dairy, razor blades, vitamin d, coffee, pasta...
Take a picture of your face in good light conditions as it looks today and send it to me. Then you spend one month doing the EXACT OPPOSITE of your wonder method. That is, if your claim is that dairy causes your face to break, you indulge in massive amounts of dairy products. If it's shaving, you start shaving every day. You keep this regimen for one month's time.
Then you send me a new picture of your face in equally good lighting. If in that picture, your acne has gotten significantly worse I will pay you $2000, no questions asked. I'm sorry that I'm poor so $2000 is all I can afford to wager, but perhaps we can make it into some kind of crowdfunding, where everyone chips in a little to produce some new research?
I'm totally serious about this "challenge."