No not as a miracle cure for weight loss... surely by now you know that I don't endorse such nonsense.
I mean the power of oatmeal (oat bran for me) to satiate. To leave you with a feeling of fullness which lasts for hours.
I knew that my oat bran with almond milk breakfast was very filling, but now there is research to support this personal experience and to explain why it occurs.
The researchers in this study collected information on how the participants were feeling, e.g., if they 'felt full,' 'were hungry' and what was happening to the oatmeal and the comparison food - ready to eat cold cereal - in the body, i.e., how it was being digested. The participants reported their feelings at several different time points up to four hours after they ate their assigned breakfast.
It is important to note that the participants each ate both meals, but in random order and about a week apart. The meals were 1) Quaker oatmeal and 2) Honey Nut Cheerios. The meals were served with the same amounts of skim milk and had the same amount of total calories. I do not eat Quaker Oatmeal - but I think they used the kind that you cook with hot water. I use oat bran which I cook with water and eat with low cal almond milk (+aspartame). I can say with certainty that if I had equal calories of cheerios and oat bran the cheerios would be half the volume of my oat bran. And I believe that what you see has an effect on your feelings of satisfaction and fullness.
Anyway, the study was well done. The lead author/researcher is Candida Rebello - a nutritionist. You can read the summary abstract here.
Putting the reports from the participants together with the lab results, the researchers could assert that the oatmeal breaks down more slowly, is thicker going through the small intestine, among other things and is more satiating than the cereal. There are a lot of details in the article that I am not taking the time to explain, and some I could not explain even if I had the time. But I think I have shared enough to give you the evidenced based take home message. Choose oatmeal over cold cereal.
As for myself, I never eat cold cereal as a breakfast. I believe that it offers too many calories per ounce (it is energy dense) and as this research suggests, doesn't stay with you very long. I do sometimes have a taste of it as part of my discretionary (treat) calories.