Approximately 75 percent of the sodium we consume in our diet is derived from salt added by the manufacturer to the foods we buy. In addition, foods served by restaurants may be high in sodium. An important first step is to read the food label and determine the sodium content of the product you are planning to buy. Keep in mind that the sodium content can vary depending on the brand. For example, the sodium content of regular tomato soup may be 700 mg per cup of the prepared soup in one brand and 1,100 mg per cup in another brand. Reading labels, comparing sodium contents of foods, and purchasing the lower sodium brand may be one strategy to lower total sodium. Use the following guidelines to reduce the sodium in your diet:
Buy fresh, plain frozen, or canned “with no salt added” vegetables.
Use fresh poultry, fish, and lean meat, rather than canned or processed types.
Use herbs, spices, and salt-free seasoning blends in cooking and at the table.
Cook rice, pasta, and hot cereals without salt. Cut back on instant or flavored rice, pasta, and cereal mixes, which usually have added salt.
Rinse canned foods, such as tuna, to remove some sodium.
When available, buy low- or reduced-sodium, or no-salt-added versions of foods.

Additional Resources:
http://edis.ifas.ufl.edu/pdffiles/HE/HE69600.pdf