Meat – Freezing meat – whole or in pieces

I suggest you read the transcript to the Good Eats show on freezing, or, better yet, find a copy of the episode to watch. (Good Eats is an American TV show focusing on food science.) Here are some relevant excerpts:

[In the freezer,] any present bacteria are going to have a devil of a time finding the moisture they require to live, breed, survive. Since they themselves contain a considerable dose of H2O, freezing halts bacterial activity altogether, though some of the little beasties can survive to decompose another day. While it is in this frozen state, the meat will remain unspoiled for years. But there's a problem. You see, home freezers work very slowly. That means that as those little H2Os start to line up inside, they'll create huge, sharp, jagged crystals that will rise up, slicing and dicing their way through cell walls, muscle fibers, and pretty much anything else that gets in the way. Now while frozen, you won't notice this damage. But when it comes time to thaw, all of those perforated cells will start to leak out moisture all over the place. It's called drip loss and it's not a sign of good eats.

Therefore, if you are buying the meat fresh (i.e., it is not already frozen), then you need to take special care in how you freeze it:

One good way to prevent drip loss is to freeze the target food very, very quickly to a very, very low temperature. So that instead of creating huge, jagged, nasty ice crystals, you get very, very tiny little ice crystals.

The episode goes on to describe a process for freezing meats at home (basically, the idea is to use small pieces of meat, freeze them separately on a sheet tray, and then once they are frozen transfer them to a bag for long-term storage).

Even though the meat will technically be safe to eat for years, there are a few caveats. For one thing, the environment in the freezer is very dry. That can cause moisture on the surface of the meats to sublimate and form ice crystals, otherwise known as freezer burn. This can be avoided by packaging the meat in a vacuum (e.g., vacuum sealed bags), however, if you don't have a good vacuum sealer, I would suggest limiting their freezing to 6 or 8 months in order to avoid freezer burn. Another reason to make sure you use an air-tight container is that fats are very good at picking up flavors of other items you might have in the freezer.

I am fairly certain the "fats will surely go bad" claim is a myth, especially since fat alone is a good preservative. Perhaps you should ask that question on Skeptics.SE.

There is some truth to this. Fats go rancid, and in particular you're worried about rancidity due to oxidation here. Freezers do not stop oxidation, but they do slow it down a lot.

The main factors in oxidation are light, heat, and metal. Storing meat in a sealed freezer-safe (plastic) container or bag and using the smallest container possible will make the meat last a very long time - usually up to a year - before there is any noticeable rancidity.

Obviously, lean meats such as chicken breasts will last longer than fatty meats such as pork, since the fat is what oxidizes. Also, vacuum-sealing and/or the addition of antioxidants will practically prevent any significant oxidation - the former because oxidation needs oxygen, and the latter because the free radicals get absorbed before they can contribute to rancidity.

Another concern is freezer burn, which is also due to oxidation (along with dehydration). This is almost always caused by improper storage. It's only ever happened once in my freezer, and that was when I ran out of freezer bags and used a sandwich bag instead (so don't do that).

Practically, for meat, oxidation in the freezer isn't really isn't a big concern if the food is properly stored, because very few people freeze meat for that long. Plant products are different because they contain enzymes which give off ethylene gas, so exposure to anaerobic conditions (e.g. freezer storage) can lead to off colours and flavours. That's why pre-frozen fruits and vegetables have generally been blanched to kill the enzymes.

Anyway, back to meat - freezing doesn't change any "nutritional profile" other than the supposed food safety issues associated with rancidity. Just cook/eat it within a reasonable time and it's practically the same as fresh.