As an Aussie, I have to jump up and down and encourage the consumption of grass-fed lamb, as it's the BEST meat in my book! I've gone off beef and pork, but my appetite is always ready to be excited by the thought of lamb.

Ground lamb is just as nutritious as any other cut, if not more so. As ground meat has a higher percentage of fat, on average, than other cuts, then you are more likely to be able to absorb fat-soluble vitamins, amongst other benefits. It would be important to ensure that the lamb is organic and grass-fed, like all meat, as the toxins (and omega-6s) are carried primarily in the fat. If you have to go conventional and pesticides worry you, go for a leaner cut.

The only reason meat is ground is because it is either taken from areas of the animal which don't present well as individual muscles/cuts on the plate, or are typically difficult to prepare without resulting in tough steaks. It has nothing to do with how nutritious the meat may be. I love the flexibility of ground meats - taco salad, burgers, sausage patties, meatza... and on it goes! Enjoy!

There's no intrinsic reason why ground meat ought to be worse than other meat, it's just a trend that lower quality meat will be ground, since it's cheaper. Apparently you can come across ground meat that contains additives or fillers, but in the UK I've never encountered this.

What might the downsides of cheaper meat be? If we're assuming that the likelihood the lamb was grassfed/conventionally finished is a separate factor, then the main characteristics of cheaper cuts just seem to be more fat and more connective tissue. Presumably from a paleo perspective these are both good things (connective tissue = gelatine) it just means that the meat might be a bit tougher. Breast of lamb, in my experience, is just an intensely fatty cut, so there shouldn't be much to choose between the two, other than based on how you want to cook it. I would guess that the ground lamb would contain more protein and less fat, but for all I know, the ground lamb in this case is just ground lamb breast.

Purely in terms of economics, it's probably worth noting that when buying meat it's the proteiny, nutrienty, meaty bit that you're paying for; while fatty meat might be more calorific, if you want a source of sheer fat then butter is often as cheap and more nutritious.

Yes, you are correct, David, most people just think that it is "not as good" because it's ground up, and feel that they have lesser options to prepare it, which essentially is not true. I have loved ground lamb, all lamb :-) all my life, and find that it quite lean and has remarkable taste when grilled, or stuffed into jalapenos, etc. So memostotle, go forth :-) and enjoy that ground lamb, and live healthy.

i love lamb personally, and many leaders of the paleoprimal way of living are big lamb-fans, too. Sisson comes to mind straight away. Nutrition wise i think its just another good red meat. And i do kind of think that lamb in general may be less a part of the industrial system than, say, cows. Generally speaking regarding us here in the US. Im sure there are lamb farms out there but i mean, its prolly easier to get a higher quality of lamb than it is beef. No?