Actually, there is a difference between diet and regular soda.
  Normally, diet soda is better for you - doesn't raise blood
  glucose levels, lower in calories, etc. BUT - when drinking,
  SUGAR (in regular sugar soda) helps slow down the absorption of
  alcohol in the body. In other words, diet soda and liquor will
  get you drunk quicker and harder, but regular soda slows down
  the alcohol. "