Chocolates do not cause acne.
So does dirt.
UV light does not help your acne.
Acne is caused by bacteria. They thrive in glands or pores on the face clogged with oil and dead cells. This is the real cause of acne. Nothing you eat can cause acne, although they may aid in its breakout. The dirt your face gets doesn’t get to the pores and therefore it cannot cause acne. Long exposure to sunlight won’t cure your acne. Well, slight sunburn may cover them, but if you burn your face too much, the irritation may even lead to more acne.