Maybe this has been beaten to death already, but I really would love to hear others opinions about this.
For breakfast, all my life, I've eaten egg white omelets with orange juice or had a granola bar or two in the morning before running out the door. Now that I have settled in, I would like to start eating Cheerios I've already tried Honey Nut Cheerios and I'm hooked. But how healthy, really, is Cheerios as part of a healthy diet and exercise routine? Or what do you consider the healthiest store-bought breakfast cereal??
The original style plain Cheerios is healthier than the Honey Nut or other sweetened varieties. In general, the healthier cereals are whole grain cereals with high fiber and the least added sugars and sweeteners.
However, many dry cereals have high glycemic indexes, so they not be too good if you have blood sugar control problems or pre-diabetes or diabetes, or want something to keep you full for a longer period of time. Plain oatmeal is likely a better choice if this is a concern for you.
I agree with tjlhb that oatmeal is a good choice. Oat groats or steel cut oats is even better if you don't overcook them. The instructions on the package usually call for overcooking because it's not really about health, it's about destruction. :-)
If you decide to use regular oatmeal, go for the slow cooking Old Fashioned Oats. Not much cooking is needed because they already steamed it and smashed it through steel rollers.
Steel cut oats is what I use. It's a healthy choice if not overcooked. That means it should be a little chewy when you eat it (not mush).
About Cheerios: Cheerios is made from oats so it sounds like it should be healthy. And the front of the box probably states that it's "Whole Grain". Right? But Cheerios is made from flour. If you take a whole grain and grind it into flour, it's not whole anymore. Therefore, it gets absorbed into your system faster. Faster absorption means it gets digested faster. You need an intact whole grain (minimal processing) that will be digested slowly. Then it's more likely to keep your blood sugar steady and keep you satisfied longer.
Processed foods are not about health. To the extent they are processed, they are nutritionally degraded. Always look for whole unprocessed foods or minimally processed foods.