Rice, oats, wheat, quinoa, bread, pasta, flour and other grain foods: nutrition, processing, storage and cooking.
Flatbread is not automatically lighter: a small pita may be moderate, but a large naan or wrap can weigh as much as several slices of sandwich bread.
A traditional corn tortilla usually has fewer calories per piece; fiber has no universal winner because a whole-wheat flour tortilla can exceed refined versions of either type.
A bagel is not necessarily dramatically more calorie-dense than bread by weight; one bagel simply tends to weigh as much as several slices.
Plain oatmeal starts with an advantage because it has no added sugar and provides soluble fiber; packaged breakfast cereals vary so widely that the label determines the comparison.
Granola can be nutritious, but it is usually much more calorie-dense than plain oatmeal because it is baked with energy-rich ingredients and eaten dry.
Whole grain describes the intact grain components—bran, germ, and endosperm—in their original proportions. Whole wheat is the wheat-specific version. So whole wheat is whole grain, but a whole-grain food can use oats, rye, brown rice, corn, or other grains instead of wheat.
“Multigrain” describes variety: more than one grain is used. “Whole grain” describes processing: bran, germ, and endosperm remain in the grain ingredient. A bread can be both, but multigrain on its own does not guarantee that any particular grain is whole.
In the U.S., corn flour and cornmeal are both ground corn, but corn flour is much finer. Cornstarch is different again: it is isolated starch used mainly for thickening rather than for the grain texture of cornbread or polenta.
Self-rising flour is a prepared flour with leavener already built in, while all-purpose flour lets the recipe control leavening and salt separately. They can sometimes substitute for each other, but not as a blind cup-for-cup exchange.
Cake flour is designed for tenderness. Its lower protein and fine texture reduce gluten-forming potential compared with all-purpose flour, helping delicate cakes bake with a finer, softer crumb. All-purpose flour can still make good cake, but the recipe and mixing method matter more.
Bread flour is usually higher in protein than all-purpose flour, so it builds a stronger gluten network and often absorbs a little more water. All-purpose flour can still make excellent bread; the trade-off is usually a softer, less chewy structure rather than a failed loaf.
Both leaveners can create carbon dioxide, but they are designed for different chemical environments. Baking soda needs enough acid in the formula; baking powder carries its own acid system. Swapping them without reformulating can change rise, flavor, color, and texture.