Sugar—Sweets and refined carbs raise glucose levels, which increases advanced glycation end products, which in turn interferes with the repair of collagen and elastin, a protein that allows skin to retain its shape.
Saturated Fat—Found in marbled meats and full-fat dairy products, saturated fats may make you look older. Experts say that eating a lot of saturated fat can induce skin-aging inflammation.
Alcohol—With the exception of resveratrol-delivering red wine, alcohol can take a toll on your skin. It dries out skin and when metabolized in the liver, it creates skin’s enemy: free radicals.
Source : http://www.swansonvitamins.com/blog/health-tips-2/3-foods-to-avoid-if-you-want-to-look-young