[wtallis]

To give a specific example: many preservatives and industrial techniques can alter the flavor of a dish in unpleasant ways, so industrialized food just covers up those flavors with salt. The worst examples would be the "flavor packet" that comes with ramen noodles: some of these deliver a full gram of sodium. But most frozen meals have unreasonably high levels of sodium as well. If you prepare your food from raw ingredients, you at least have the option of using less salt, to the betterment of your blood pressure.