A potato comes from the ground, an egg from a hen. But where did that Pop-tart come from? "Unprocessed, whole foods will give you the most benefits," Berman says. Processing takes out nutrients such as antioxidants and fiber. What's worse is that a lot of processed foods tend to sneak in things that aren't really necessary like extra sodium and sugar. There's nothing wrong with indulging the occasional processed food craving (sometimes a bag of potato chips is too hard to resist!). But if you're trying to shop healthier altogether, be on the lookout for products that have been minimally processed.
If all you have time for is a quick snack from the gas station or drugstore, know that you do have options, and if you know what you're looking for, it will be easier to find. When we asked registered dietitians to recommend snacks to buy at the drugstore, they tended to go for things like nuts and seeds that pack plenty of flavor (hi, wasabi chickpeas), plenty of protein, and not a whole lot else.
To help you learn how to eat healthfully, start with the U.S. Department of Agriculture's (USDA) dietary guidelines system, which you can find at http://www.mypyramid.gov. The MyPyramid system, which looks somewhat like the familiar food pyramid of old, offers guidance based on individual needs and replaces "serving" recommendations with actual amounts of food. It also emphasizes the importance of balancing nutritious (and tasty!) food choices from all food groups every day with daily physical activity.

For instance, foods rich in vitamin E and beta-carotene are healthy and can help reduce cancer risk. However, the U.S. Preventive Services Task Force (USPSTF) and the American Academy of Family Physicians (AAFP) recommend against taking vitamin E or beta-carotene for the prevention of cardiovascular disease. People who smoke or are at risk for lung cancer also should avoid beta-carotene. It can increase their risk of lung cancer.