How do you know what suffering I inflict by eating dead food? How do you know the food I eat suffers at all? It seems pretty dead to me when I eat it.
Go visit an abattoir.
If you know that eating meat is wrong and you make no effort to stop doing it, you're causing yourself suffering also. Whether or not you repress the pain is irrelevant. Repressed pain is worse, spiritually, at least, than experiencing much more intense pain head-on (IMO)...
There's not a huge difference between the logic involved in determining that racism is immoral. We have, historically, justified mass-scale wrong-doings in the absence of race equality. Species equality takes slightly more enlightened thinking, in the sense that it is one step removed - again. What I'm saying is: some people, historically, failed to recognize the oneness of the human race; and, now, some people fail to recognize the oneness of the planet... It is in our nature to be skeptical, to re-act based on fear... but it is also our nature to look back - once the fear has subsided - and think about what really happened...
There's clearly a trend towards veganism and eco-friendly lifestyles because we have witnessed the (moral and the practical) ramifications of disregarding and / or mistreating nature.
Note: True species equality is not possible, because of the food chain...
What I'm suggesting is: it should be illegal to mistreat animals, but not to eat them.
And, like I said, the law is trending towards this.
The standards are getting better and better.
They're still awful; it's going to take time.
But, at least, we're getting somewhere.
How do we make a difference, as individuals?
We stop consuming animal products and we voice our opinions; we take personal responsibility for the consequences of our actions; we defend those without voices; we say, "this is wrong"... and the fact that it annoys people (in the same way slave owners were infuriated by outspoken non-racists) is to be expected... People tend to shoot the messenger. There is, more often than no, no tangible reward for a good deed.