" Individuals were randomized into one of three breakfast conditions—oatmeal made from quick oats, the same number of calories of Frosted Flakes, or just plain water—and then the researchers measured how much the subjects ate for lunch three hours later. Unsurprisingly, those who had eaten the oatmeal felt significantly fuller and less hungry after a few hours and indeed went on to eat significantly less lunch. Overweight participants in the oatmeal group ate less than half as many calories at lunch, hundreds of fewer calories compared to the other groups. How did the cereal group fare? The breakfast cereal was so unsatiating that the Frosted Flakes group ate as much lunch as the breakfast-skipping water-only group.4902 It’s as if the cereal group hadn’t eaten any breakfast at all. "

― Michael Greger , How not to diet