A sandwich is a go-to lunch for many of us. It’s easy to make, a great way to use up leftovers (hello, roasted turkey) and seemingly healthy—after all, you can pack it with all the veggies and protein you want. Unfortunately, a new study is suggesting that sandwiches are giving us an unhealthy dose of   sodium. Researchers from the U.S. Department of Agriculture found that sandwiches account for 30 to 46 percent of an individual's sodium, but that's based on a maximum of 2,300 mg per day. In Canada, the adequate intake of sodium—as determined by Health Canada—is 1,200 mg per day. Meanwhile, 2,300 mg is considered the upper limit. And, according to the study, those who ate sandwiches consumed 600 mg of sodium more daily than non-sandwich eaters. So where does all this sodium come from? Here's a quick breakdown: Bread (2 slices) – 340 mg Mustard (1 tsp) – 60 mg Deli turkey (2 ounces) – 670 mg Cheddar cheese (1 ounce) – 175 mg Total: 1,245 Add a pickle and that’s at least another 300 mg of sodium! All of that adds up to more than the adequate intake and more than half the upper limit of sodium you should have in a day. And excess sodium has been linked to high blood pressure and heart disease. To avoid skyrocketing your sodium intake, use leftover roasted meats instead of deli meats. Instead of mustard and cheese, spread your sandwich with hummus, which will also give it a healthy dose of protein. And if you’re feeling super healthy? Switch up the bread for lettuce! Or, if you want an alternative to that turkey sandwich, try one of these other recipes for using up leftover turkey. (Photography: Thinkstock)