Since thw british government isn't forcibly preventing anyone from getting porn your point fails.

But, trying to answer your question: if coca cola marketed their product as having health benefits they'd be stopped by one branch of government. If they advertised it as being totally safe in inlimited quantities they'd be stopped by another regulator. The food industry haa been warned to make labelling clear and to reduce sugar, salt, and fat content or face strict regulation. So, yes, i'm happy for government to regulate the food supply.