Why is my macaroni salad absorbing all the liquid? I like to prepare my macaroni salad and refrigerate overnight.  The next day I find that my salad is dry, because the salad dressing has absorbed into the macaroni.  What causes the salad dressing to absorb into the marcaroni?  Please help me?
Pasta absorbs liquids, because it is made of starch, and starch absorbs water.  Tossing the pasta with oil will reduce the absorption, by coating them in a water-repellent layer. 

Beyond this, the solution is simple: don't drain as much water from the cooked pasta, and add more dressing.  There's a limit to how much moisture pasta will absorb.