Would you say growing wheat to feed your own farm animals should be regulated by the federal government? SCOTUS decided in Wikard v Filburn [1] that a farmer growing wheat for private use was in fact inter-state commerce. This decision has been used to uphold all manner of federal laws that on their face appear to regulate private conduct totally within the confines of a single state.

[1] https://en.wikipedia.org/wiki/Wickard_v._Filburn