I spent a little bit of time trying to verify if this quote was real and it does look like it's a legit quote.
"It is certainly preferable to raise vegetables, and I think, therefore, that vegetarianism is a commendable departure from the established barbarious habit.
That we can subsist on plant food and perform our work even to advantage is not a theory, but a well-demonstrated fact. Many races living almost exclusively on vegetables are of superior physique and strength.
There is no doubt that some plant food, such as oatmeal, is more economical than meat, and superior to it in regard to both mechanical and mental performance.
Such food, moreover, taxes our digestive organs decidedly less, and, in making us more contented and sociable, produces an amount of good difficult to estimate.
In view of these facts every effort should be made to stop the wanton and cruel slaughter of animals, which must be destructive to our morals.
To free ourselves from animal instincts and appetites, which keep us down, we should begin at the very root from which we spring: we should effect a radical reform in the character of the food."
~ Nikola Tesla
Here's one of the biggest geniuses in recorded history and one of the main reasons anyone has electricity and is even online on their phone or computer to read this message.
He's also credited with many other amazing inventions including the radio... And his words are quite clear in regard to the subject and there are other geniuses who felt similar.
That doesn't mean he or the others are 100% on the subject of diet and compassion for animals just because of being such a genius in other ways, however... It should hopefully give just about anyone at least a pause and a few moments to consider such deeper if they haven't already.
(I don't own the rights to this image, I found it on social media and am using in a fair use educational sense)
Also, here's a few more interesting links on the subject.