Bigger brain/more intelligence doesn't justify killing and eating animals

A person wrote:
" the awkward/annoying moment when vegans/vegetarians use social media to rant about meat eaters and how horrible they are for eating fellow earthlings, when it was thanks to our ancestor's meat-rich diets that our brains grew bigger and thus more intelligent, so that humans were able to go on to develop the technology vegans/vegetarians use today to rant about meat-eaters..."
My reply:
It is severely flawed that ”more intelligence” would make it morally justified to inflict unnecessary suffering and pain on another sentient being.
Apart from that, our ancestors ate a primarily starch-diet: http://www.drmcdougall.com/misc/2009nl/feb/starch.htm

http://news.bbc.co.uk/2/hi/6983330.stm



“Most people would agree with the proposition that it’s wrong to inflict unnecessary suffering and death on animals. We could have an interesting philosophical discussion about what 'necessity' means but the reality is if it means anything, if it means anything at all, it means we can’t justify suffering and death for reasons of pleasure, amusement or convenience. 

If we had a rule that said, ‘It’s wrong to inflict unnecessary suffering on children, but it’s OK to beat them if you enjoy watching them suffer’, that would create an exception that would not only be perverse but would make the rule silly. 

Similarly if we say it’s wrong to inflict suffering and death on animals, well what’s our justification for eating meat?  We don’t need to eat animals to be optimally healthy. I have been a vegan for going on now 31 years and I would daresay that I have more energy and suffer from fewer colds and viruses than most of the people I teach who are young enough to be my grandchildren. So the idea that you need animal products to be optimally healthy is simply false.

The best justification that we have for inflicting suffering and death on 56 billion animals a year is that they taste good. We are saying it’s wrong to inflict unnecessary suffering on animals, but on the other hand we participate in this all the time. 

We’re not on a desert island, or in any situation of conflict with non-human animals. We simply choose to eat them because we like the taste or the convenience of going out to the fast food place next door. It’s simply a matter of pleasure or convenience.

“ Quote: http://www.abc.net.au/radionational/programs/scienceshow/vege-mice-response/4674360