Nutritional information is information. It is legislated and regulated, but not a contract. The manufacturer has to comply with regulations, but that is not considered a legally binding contract, and failure to comply does not constitute breach of contract. To be clear, just because there's a legal penalty attached for failure to comply does not constitute a contract between the manufacturer and the government.

Similarly, the individual is not bound to any contract to the manufacturer by purchasing a can of beans. They are, on the other hand, when purchasing software. It's a crucial difference.