Oatmeal is a wonderful food - it is heart-healthy and high in vitamin B, calcium, iron, magnesium, phosphorus, and potassium. But, the oats are also very high in phytates / phytic acid - a form of phosphorus that inhibits the absorption of many of those healthy vitamins and minerals, and over the course of time can cause deficiencies.
All you need to do to maximize the health benefits of your oats is soak them in warm water during the night and they will be ready to eat in the morning. You will find that soaking them makes them cook almost as quickly as instant oats. You can also ferment your oats by adding some vinegar or yogurt to the water.
The same should be done for all grains, nuts, legumes and beans to maximize vitamin and mineral absorption.
I have to admit that I am really bad about doing this, because it requires planning ahead, and that isn't one of my strengths. But it is so important to do, as studies are showing that the buildup of phytic acid is causing vitamin deficiencies in many people. Remember that most of the processed foods on the grocery store shelf that contain grains, nuts, beans and legumes are not soaked!
Fallon, Sally. Nourishing traditions the cookbook that challenges politically correct nutrition and the diet dictocrats. Washington, DC: NewTrends Pub., 1999.