Most of us unknowingly eat processed sea vegetables every day. Manufacturers use them as thickeners and stabilizers in such products as ice cream, instant pudding, whipped toppings, salad dressings, and even toothpaste.
Unprocessed sea vegetables, though, haven't caught on much outside of Asia. It's a shame, since they're dense with vitamins, minerals, and protein, yet low in calories. You can usually find plastic bags of dehydrated sea vegetables in health food stores, or in the Asian foods section of larger supermarkets. After rehydrating, chop them up and add them to salads, soups, stews, or stir-fries.