I am 57 now and graduated to vegetarian food to lose weight. I finally gave up meat altogether. Imagining back to when I was a young student to be vegetarian would be difficult. It is partly life style, takeaway city is full of places for carnivores. It is partly money, being vegetarian is best if you can afford to eat higher quality food - which I can now at my age. On ethics, well I believe I should eat what I need and not waste food. I also believe that other carnivorous animals, like cats (who cannot recognise that a vegetable is edible), are part of an ecological system like humans. Humans, unlike cats, could choose to be vegetarian and survive, so eating animals can be challenged ethically maybe. But on balance I can't show an ethical red card to human carnivores. Especially, for example, say humans that are relatively poor, live by the sea, and survive on fish.