As we probably all agree, the pleasure per unit time for eating a zebra is probably higher than the pleasure per unit time for eating grass. (Compare the human experience of eating steak with that of eating kale.) But zebras eat grass for much longer.
Eating grass (and any food) can also involve unpleasantness if you’re eating low-quality food (as well as if you’re nervous about predators or conspecifics, etc.).
As we probably all agree, the pleasure per unit time for eating a zebra is probably higher than the pleasure per unit time for eating grass. (Compare the human experience of eating steak with that of eating kale.) But zebras eat grass for much longer.
Eating grass (and any food) can also involve unpleasantness if you’re eating low-quality food (as well as if you’re nervous about predators or conspecifics, etc.).