The appellee for many years past has owned and operated a small farm in Montgomery County, Ohio, maintaining a herd of dairy cattle, selling milk, raising poultry, and selling poultry and eggs. It has been his practice to raise a small acreage of winter wheat, sown in the Fall and harvested in the following July; to sell a portion of the crop; to feed part to poultry and livestock on the farm, some of which is sold; to use some in making flour for home consumption, and to keep the rest for the following seeding. The intended disposition of the crop here involved has not been expressly stated.Roscoe Filburn wasn't some sort of yeoman farmer milling his own flour from his own wheat. His farm was a businesses, part of which involved selling chickens and eggs, and the wheat he grew had a direct impact on his ability to sell chickens and eggs. Now, you can argue with this wisdom of this sort of scheme, but if it's within the power of Congress to establish wheat quotas, it's undoubtedly within the power of Congress to count wheat that will quite clearly impact the stream of commerce against that quota.
There's no exact parallel to Health Care Reform in Wickard. An individual who refuses to buy health insurance is, at that moment, not an active participant in the market for health insurance or health service. But it's well within Congress power to recognize that while at that moment they are not buying health services, it is inevitable, or close enough to inevitable, that they will at some point be participants in that market.