Processed foods have been altered from their natural state for safety reasons and for convenience. The methods used for processing foods include canning, freezing, refrigeration, dehydration and aseptic processing.

We tend to think of processed foods as bad, but it turns out that many processed foods are not unhealthy. For example, milk would be considered a processed food because it is pasteurized to kill bacteria and homogenized to keep fats from separating. While some people prefer to drink raw milk, most of us should consume the "processed" version we find in our grocery stores.

Another healthy example of food processing is frozen vegetables. While fresh may be best, freezing vegetables preserves vitamins and minerals and makes them convenient to cook and eat all year around. Fruit and vegetable juice is also an example of a healthy processed food. In fact, some orange juice is fortified with calcium to make it even more nutritious.

Of course, there are a lot of processed foods that aren't good for you. Many processed foods are made with trans fats, saturated fats, and large amounts of sodium and sugar. These types of foods should be avoided, or at least eaten sparingly.

Processed foods that may not be as healthy as fresh foods include:

Processed meats might be some of the worst of these foods. Eating these meats may increase your risk of colorectal, kidney and stomach cancer. Processed meats include hot dogs, bologna, sausage, ham and other packaged lunch meats.

These processed foods and prepackaged meals are very convenient and popular. If you do shop for these foods, be sure to look for products that are made with whole grains, low in sodium and calories, and free of trans fats. Make sure you pay attention to serving size, too, and balance out the processed foods you eat with a delicious fresh salad and some whole grain bread.

Given the change in many people's lifestyle, your daily intake needs to be considered wisely.