Pretty obviously the picture on the right side is rolled oats. The picture on the left is steel cut.
Old Fashioned Rolled Oats - These are made by steaming the groats and flattening them with a roller. The Quaker Old Fashioned Rolled Oats are very thinly rolled, as are the store varieties by the same title. If you look hard, however, you can often find rolled oats that are twice as thick as the Quaker variety, and these make a lovely, less creamy version of oatmeal than the Quaker ones do. Quaker sets the industry standard, so theirs is considered REGULAR Old Fashioned Rolled Oats. If they are thicker, they are called THICK Old Fashioned Rolled Oats.
Quick-cooking rolled oats -- These are made by flattening pre-cut groats. They cook in about 5 minutes.Steel Cut Oats or Scottish Oats or Irish Oats- These are groats which have been cut into two or three pieces. Cooking time is considerably longer than for rolled oats.
So here's basically what I figured out. The actual nutrition value of each type of oat is pretty much the same but it's the glycemic index of the oats that's the important part and what makes the steel cut oats the better choice for breakfast.
See here's the thing... the important part with food is how much is done to it to break down the cell structure before you get it and eat it. One way this can be done is by cooking the food item. The longer the cooking time, the greater the breakdown of the cell walls, and the faster that food can enter your blood stream and the faster your body will react to it by producing insulin to break down the carbohydrates (sugars) into simple, readily usable forms.
We want the happy medium, ... breaking down the starches just enough to make them tasty and easy to digest, but not so long that they become unfavorable, i.e. high on the glycemic index. The less you break down your foods, the less the glycemic reaction will be, the more stable your blood sugar will remain, the longer you'll stay "full" and the fewer cravings you will have.
So, when they steam and toast rolled oats they are actually raising the glycemic index and so that type of oat raises your blood sugar faster then steel cut.
And there you go, the long story of why I am going to eat steel cut for a few weeks. It's my own personal experiment on breakfast food. I mixed in a handful of raisins, and a tablespoon of peanut butter. It was the yummiest thing I've had for breakfast in awhile and here it is several hours later and I'm still comfortably full. Things are looking good :)
*They take forever to cook BUT if you soak them overnight they cook as quickly as rolled oats do:
Soak 1/2 cup oats and 2 cups milk (or water) overnight, covered, in med-sized bowl. Transfer to medium saucepan, add 1/2 tsp salt and 1/2 tsp cinnamon and cook on stovetop over med-high heat to bring to a boil. Lower heat and maintain a gentle simmer and cook, uncovered, stirring frequently until oats are softened and most of liquid is absorbed and becomes thick, about 10 minutes. Either serve right away or...the leftovers can be transferred to a resealable container, cooled and covered and stored in the fridge for up to a week reheated as needed. Superduper yummy!!