If the government places limits on how much salt corporations can put in food then that means that you ultimately control how much salt is put in your food. Using your salt shaker.
If there are no limits then that means that whatever corporation had a hand in making your food has control over how much salt is in your food instead of you. There's no such thing a salt unshaker. You can't get the salt out once it's been put in.
And, remember, the only reason you know how much salt was put in your food before you got it is that there are regulations responsible for getting that information put on the package. If business had its way not only would you not control how much salt was in your food, you also wouldn't have a way of finding out how much salt had been put in there.
Without regulation not only are you not in control, you're not even aware of what those who are in control are doing. Things are done to you not just without your consent, but also without your knowledge.
Regulations on business place the power in your hands, an absence of regulations on business takes the power out of your hands.