Yes, definitely meat because it’s something most people eat everyday, unlike carrots, or apples, for example.
My husband always tells me that the point is to give up something you really enjoy, so it doesn’t have to be meat. Meat would not work if you’re a vegetarian, for instance. The other thing he tells me, is instead of giving something up, you can take something on. Like, say a rosary (if you don’t normally do that), go to a daily mass after work, etc.
I find that at work, we would always go to Team Lunches only on Fridays, and many restaurants close by did not have vegetarian dishes (or they’d have seafood, which I am not a fan of), so I would have to eat meat. This is the case where you can give something else up, or taking something on instead.
I says there that ///One belief of why meat was chosen is because most people feel that giving up meat (beef and chicken) is an inconvenience. The Church asks us to inconvenience ourselves sometimes to serve as a reminder that they should always have God as a top priorty and pleasures as a lesser priorty.
Another belief is that in many poorer countries, beef is a specialty. For us to give it up, helps us to remember about people who are less fortunate than we are.///