There is a laundry list of reasons why people should greatly reduce the amount of processed foods in their diet, high in refined sugar and flower, food colorings and chemical additives, nutrient deficient empty calories, and of course high sodium levels just to name a few.
A recent news article Huge range of salt found in processed food sheds some much needed light on the subject, but in my opinion falls short of educating the public on the importance of maintaining a healthy diet by consuming whole natural foods in the complex unprocessed unrefined form.
It is very important to realize that even though the body requires certain levels of sugar, and fat, and sodium, it is no where nears the levels the westernized "processed food diet" provides. The problem with processed foods is that they are made with refined ingredients that have basically been processed to the point where not only do they lack any nutritional value but in the refined "simple" form they cause more harm than good.
Take unrefined sea salt for example... it can be considered a "complex food form" since (depending on the verity) can contain up to %15 minerals, compared to refined white table salt that is nearly %98 sodium-chloride and %2 chemicals from processing. These refined salts can actually prevent the body from absorbing water Iodine.