There are many ways to measure the health value of a food, and one such way is the glycemic index. Foods rated high on the index create fluctuations and even spikes in our blood glucose and insulin levels, which is something to be avoided. The lower the GI number the better for your glucose levels. The ratings range from zero to 100 and pasta is generally between 30 and 60 on the GI scale.
To keep the GI rating of your pasta low, you need to eat it al dente. The firmer the noodle is the longer the digestion time. Slower digestion means a lower spike in blood sugars, and that is healthy!
So cook your pasta al dente, which literally translates from Italian to mean "to the tooth." Your noodles should give the sensation of slight resistance when chewed.