Great question! I think this is very dependent on the individual (what a 80-year-old Japanese woman eats for breakfast will look very different from a 30-something male construction worker), but as a rule of thumb I usually fill about 1/2 - 3/4 of my rice bowl, never over the top, which is already a single-serving design.

It's breakfast, a meal that is proportionally smaller than my other meals, so it's really not a lot, but enough to carry me to lunch without feeling starving 😊 The best way to know the perfect balance for you is to try it 2-3x and see how you feel by your lunchtime!