The most important thing is the intent with which you eat and the results. If you are mindful, you can see that there are different results and different intents for eating different foods in different contexts. Meat is bad karma because it carries with it the essence of murder. That's more of a Mahayana idea than a Theravada one, but really, it's neither: it's just middle way, just the way things are.
Eating meat isn't wrong, but rather, it depends on the context.
In my humble opinion: For people of good moral character that need strength, it's OK to eat meat. You can see how people who are elderly and skinny need lots of protein, they might like meat, and to deny them meat and force-feed them stuff they don't like which would be healthy for them would be cruel.
However, if you are healthy and your morality isn't that great, loading up on KFC and burgers every night is bad. You'll get fat, die early of a heart attack, and I'd suspect it could even make a person cruel.
The best things in life aren't things.