Undoubtedly, you’ve heard exclamations such as, “Eat your veggies! Fresh vegetables have more nutrients than canned! Remember that the vitamins in vegetables and fruits are in the skin at some point throughout your life. While fruits and vegetables are essential to a healthy diet, the evidence regarding how they should be consumed has changed. New studies are showing that the nutritional content of vegetables remains more or less consistent, whether it is whole, peeled, fresh or canned.
Even though the skins of red apples and grapes, for example, are rich with antioxidants, the rest of the fruits are nonetheless full of benefits. The flesh of the apple is full of potassium, fiber and vitamin C. Vegetables and fruits with both red skin and flesh, such as bell peppers, tomatoes and red berries, are excellent sources of lycopene throughout.
If you’ve never learned to enjoy the skin of the sweet potato, don’t fret; the nutrient content of the tuber isn’t significantly compromised by the skin’s absence.
Canned vegetables have also gotten a bad rap for the past few decades. Granted, many canned vegetables simply aren’t as tasty as their fresh alternatives (many veggies tend to get mushy or limp during the canning process), and water soluble vitamins can degrade. Nevertheless, on the whole, canned vegetables are still quite nutritious. This is because the vitamin content of fresh vegetables diminishes after they are picked, and since fresh veggies and fruits must often travel hundreds of miles before landing in the supermarket produce department, their nutrients have actually degraded more than vegetables and fruits that were preserved immediately after being picked. 
While obesity is a huge problem among the youth of the United States, many obese children are actually malnourished, since their diets consist of high fat, sugar, salt and carbohydrate convenience foods. Although it is generally believed that fresh fruits and vegetables are economically prohibitive in many lower-income households, the option of canned fruits and vegetables could provide a nutritious and inexpensive alternative.
In order to get the best quality canned vegetables and reap the greatest benefits, nutritionally speaking, select low sodium and sugar canned fruit and vegetable products. While the flavor isn’t as concentrated in certain canned vegetables as it is in fresh, there are examples of canned products that are often superior in taste to the fresh versions. Canned tomatoes, for example, are often quite good in sauces, and are reliably flavorful even in colder seasons when ripe fresh tomatoes are difficult to find. Canned beans are intensely nutritious, and take far less time to prepare than traditional dried beans (even though dried beans are, in fact, less expensive than canned when measured in cost per lb.). Incorporating canned vegetables in soups and stews is an excellent and cost-effective way to incorporate vegetables into the diet.
By Julian Omidi
 O’Conner, Anahad: Really? The Claim: Fresh Produce Has More Nutrients Than Canned New York Times 5/27/2013 http://well.blogs.nytimes.com/2013/05/27/really-the-claim-fresh-produce-has-more-nutrients-than-canned/?ref=health