1. You reach for multigrain bread or cereal
Foods labeled 7-grain or multigrain may seem like the healthiest choices—especially with new findings showing that a diet rich in whole grains protects against heart disease, cancer and other ills. A recent study by Swedish researchers found that women who consumed generous amounts of whole grain foods had a 33% lower risk of colon cancer than women who consumed the least.

2. You buy bottled water laced with vitamins
It's a measure of how health conscious we've become that water is now fortified with nutrients and even medicinal herbs. But when asked for the lowdown on so-called enhanced water, Prevention advisor Elizabeth Somer, R.D., counseled: "Save your money." Many are bloated with unnecessary calories. The label of one leading brand, for example, reports that it supplies half the daily requirement for some nutrients. But to get that amount, you have to drink the whole bottle, which contains 125 calories. And for that you get just 6 of the 40-plus essential nutrients provided by most supplements

3. You choose veggie chips over potato chips
You'd think you were at a farmers' market when shopping the snack aisle these days. Dozens of munchies are made from carrots, spinach, kale, and even exotic tropical vegetables. But scrutinize their ingredients and you'll find that vegetable coloring is all most of them have in common with produce. What could sound more virtuous than a brand called Veggie Booty--especially when the packaging advertises kale and spinach? The ingredients label reveals that vegetables are at the bottom of the list (that means they contribute less, by weight, than ingredients at the top of the list, like oil). Many of these seemingly healthful snacks are still loaded with calories: A 4-ounce bag of Hain Carrot Chips contains 600 calories--just as much as Lay's Classic potato chips.

4. You choose snacks that are "made with real fruit"
Pictures of luscious-looking fruit adorn the packaging, and the labels claim that there is real fruit inside--but don't think you can count these snacks as one of the four to five daily servings the new dietary guidelines recommend. Because current law doesn't require labels to specify how much fruit is in the product, manufacturers can brag on packaging that food is made with real fruit if it contains only small amounts of fruit juice. Other downsides: Few of these snacks provide any fiber, and some faux-fruit munchies even contain small amounts of artery-choking hydrogenated fats. And they often have as many calories--almost all from sugar--as candy. For example, a 25-g serving of Fruit Gushers has 90 calories, just about equal to a handful of Willy Wonka's Everlasting Gobstopper jawbreakers.

5. You buy low-sodium products to cut down on salt
Almost all of us could do with less salt, which has been shown to increase the risk of high blood pressure. Americans consume an average of 3,375 mg of sodium a day--way over the recommended maximum of 2,300 mg for healthy people (1,500 mg for the one in three among us who has hypertension). Because processed foods represent one of the biggest sources of hidden sodium, it's great news that manufacturers are making low-sodium alternatives. Problem is, many still contain more salt than the 140 mg most of us should get in a single serving. A 1-cup serving of a leading chicken broth labeled less sodium, for instance, contains 554 mg 1 tablespoon of reduced-sodium soy sauce has 600 mg.

6. You drink fat-free milk to bone up on nutrients Smart move.
But if you buy milk in glass or translucent containers, you may not be getting all the nutrients you should be. Although calcium in milk is relatively stable, vitamins A, B2, C, D, and E and amino acids all break down gradually when milk is exposed to light. In a study at Cornell University, levels of vitamin A fell as much as 32% when milk in plastic containers was exposed to fluorescent light for just 16 hours. Other studies have found that up to 60% of the riboflavin is lost under similar conditions. Light also oxidizes fat and diminishes the flavor of milk.

7. You toast your health with a glass of wine or beer
More than 100 studies have found that moderate drinkers have about one-third lower risk of heart disease than those who abstain. But excessive drinking--three or more alcoholic beverages a day, most studies agree--has also been proven to send blood pressure climbing. New evidence shows that even light to moderate drinking on an empty stomach can contribute to high blood pressure risk. In a 2004 study that looked at data from 2,609 men and women ages 35 to 80, State University of New York at Buffalo assistant professor of preventive medicine Saverio Stranges, MD, found that the risk of hypertension was almost 50% higher in people who drank alcoholic beverages without food than in those who imbibed only with a meal.

8. You grab a granola bar for a quick breakfast
Snatching an on-the-go breakfast is better than skipping it altogether numerous studies show that people who eat a morning meal are slimmer and have lower cholesterol levels and better memory recall than those who don't. But according to nutritionist Christine Gerbstadt, MD, RD, a spokesperson for the American Dietetic Association, many of those seemingly healthy breakfast bars so great for eating on the run are basically candy bars in disguise. Gerbstadt says "Even though they may contain granola or fruit, some bars are full of high fructose corn syrup and trans fats to keep them soft and sweet." A top-selling granola bar contains nearly the same amount of sugar--14 g--and fewer nutrients than a strawberry Pop-Tart or a slice of chocolate cake. A leading breakfast multigrain bar packs 15 g of sugar as well as heart-harming trans fats.

9. You have an after-dinner mint instead of dessert
The cooling taste of mint may sound like just the thing after a heavy meal, but it could spell trouble. According to the National Digestive Diseases Information Clearinghouse, mints are high on the list of foods that can cause heartburn, the telltale burning in the lower chest that occurs when juices from the stomach creep up into the esophagus. Mint seems to relax the muscle that keeps the valve at the top of the stomach clamped down, increasing the odds of reflux. Other surprising culprits: caffeine-containing food and beverages, such as chocolate, soda, and coffee.

10. You save restaurant leftovers to reheat later
If you stop for a movie after the meal, your health may be in jeopardy. The food needs to be in your fridge or freezer within 2 hours (1 hour if it's over 90°F outside) or you're risking food poisoning. Another concern: nuking leftovers in take-home food bags, pizza boxes, fast-food wrappers, microwave-popcorn containers, and even on some paper plates. According to Lauren Sucher, a spokesperson for the Environmental Working Group, these can leach dangerous chemicals into the food when heated.

The chemicals include phthalates and bisphenol A, which are known to cause reproductive damage in animals, as well as fluorotelomers, which can release fumes that cause a flulike sickness. The seriousness of the danger remains controversial.