Preferably something that has little to no preparation required.
I don’t think the sugar in the prepackaged ones is very healthy.
I make oatmeal with milk. Then add a spoonful of peanut butter and some ground cinnamon.
If you have one cup of skim milk with your oatmeal, assuming the oatmeal has absolutely no sugar at all (which isn’t the case), you’d be having 13 g of sugar. I usually like to mix in a spoonful of brown sugar with my oatmeal, adding another 5 g of sugar. Maybe you don’t do that; everyone’s different. Putting in half a banana would add 7 g of sugar.
A packet of Quaker cinnamon flavour instant oats has 10 g of sugar. If you have two packets, it is roughly equivalent to making regular oatmeal with half a banana (7 g), a spoonful of brown sugar (5 g), a tablespoon of peanut butter (1 g) and half a cup of milk (6 g)
Granted, the combination of making it yourself is a lot more nutritionally whole, but if we’re just comparing sugar content, it’s actually not that bad.