I think it probably depends a bit on the color persistence effect. Like when you stare at something then look away, you see the opposite color. This effect probably requires the parts of your eyes that were looking at cyan to move over the white area and create red. So if you look at it without moving your eyes, it doesn’t work
That’s around 500kg of food, or 70kg daily for a week. All you have to do is eat basically 1 body weight per day