Beauty Quickie: Dairy and sugar do not need to be completely stricken from your diet, but they should be kept to a limit. Starchy carbs, sugar and dairy all have something in common that can wreck havoc on skin. All three can cause spikes in hormones that in response cause acne. Experiment with how much dairy and sugar your body can handle without causing a breakout. If you love carbs (we know we do) stick to whole grains or fruits that have natural sugars.