The short answer is that there's no best way to eat oats. Overnight oats are, by definition, served cold in the morning. Overnight oats are oats that are soaked in a liquid overnight so that the oats can absorb the liquid - no heating up necessary. The liquid can really be anything. It can be milk, a milk-alternative like almond or soy, or water. Although, if you are going for taste, try to avoid using water.
However, if you find that you don't enjoy them cold, you can definitely let it prepare in the fridge overnight, then heat it up in the microwave in the morning. Heating up the oats in the microwave won't ruin them - this is a great way to prepare oatmeal with a softer consistency!
However, before tossing them in the microwave we definitely recommend trying them cold first! By adding extras like chia seeds, fruit, and protein when preparing it the night before, you'll have a nutritious, delicious breakfast waiting for you when you wake up - no microwave required.
If you don't have the time to measure and prepare the ingredients the night before, give Oats Overnight a try and join the hundreds of thousands of people already taking charge of their morning routine!