Britney Spears may think it’s great, but Pepsi and other soft drinks like Coca Cola, Mountain Dew and Dr. Pepper can really increase flare-ups if you’re prone to acne. Actually, you should really avoid anything that ends in “ine” — that means caffeine — because caffeine acts as a diuretic and dehydrates skin. So if you’re a coffee drinker and you have problems with breakouts, loosen the grip on your mug. If you can’t live without caffeine, switch to tea. It still has caffeine but not as much.