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As a registered dietitian, I find myself constantly answering friends' questions about the wacky nutrition advice they read on a website or in an email. Are bananas becoming extinct? (Nope.) Do Twinkies last forever? (Uh-uh.) Has a certain brand of foil-wrapped chocolate coins been found to contain a deadly chemical? (Actually, that one's true.) While there is occasionally some truth to these claims, more often than not, I find myself shaking my head, rolling my eyes, and asking, "Where on Earth did you read that?"

I recently attended a briefing that unveiled the results of the American Dietetic Association's Nutrition and You: Trends 2008 national survey, which asked a series of questions about nutrition information, attitudes, and behaviors. The survey found that TV was the leading source of nutrition information for 63% of respondents. In second place, magazines were the primary source for 45% of Americans surveyed.

But for the first time, the Internet came in third place; it replaced newspapers, which have been the third most popular source of nutrition news since the annual survey's inception in 1991. Nearly one-quarter of respondents cited the Web as their source of nutrition information. That number jumps to 42% among 25- to 34-year-olds. Since 2002, the percentage of Internet surfers seeking nutrition facts has doubled, and it's eight times what it was in 1991.

That's good news for me as a nutrition blogger. But unfortunately, not all Web sources are sound. While the survey did not cite which pages these nutrition surfers are visiting, I'm inclined to believe that many are less reliable than the well-researched, fact-checked sites I frequently visit.

Some of my favorite Web resources include the USDA nutrient data lab, where I constantly look up nutrition facts on foods and products; daily news from MedlinePlus; and, of course, Health.com. While there are qualified experts and writers contributing to other sites, there are also lots of sites with bogus information out there. Just because a site is run by a doctor or just because a company did studies on its product doesn't mean that the information is unbiased or accurate. Here are a few tips to keep in mind when surfing the Web for nutrition news.

Go to credible sources
Websites of professional organizations like the American Dietetic Association, government agencies such as the U.S. Food and Drug Administration, medical institutions such as the Mayo Clinic, or educators like Harvard University provide information you can trust.

Look for the details
Is the information old or new? Nutrition is a field that is rapidly changing, so seek information that has been published or presented in the last year or two. Is the writer credentialed? Look for articles that quote doctors or dietitians—or pieces that are written by these professionals. Don't take the words "research" and "study" without a grain of salt: It's often hard to draw "news you can use" from certain experiments—for example, those that aren't peer-reviewed or published in a credible journal, those that are performed on animals, or those that are purely observational—which means that other factors could be involved in the outcome. A good article will explain how a study was performed and what it should actually mean for our eating habits.

Be a skeptic
If it sounds too good to be true, it probably is. Red wine contains a compound that seems to protect against aging, for example, but experts have said that we can never drink enough red wine in a day for it to have an impact—at least not without suffering negative health effects from the alcohol. On the other hand, if something sounds too horrible to be true, that's probably the case as well.

Read the "About Us" page
Be sure to look beyond the bold and go to the small print to see who is behind the information or if it is a bogus organization. It may turn out that a seemingly unbiased organization is sponsored by a food company that's promoting its own products, or an animal right's group that's posting bad news about eating meat, for example. Knowing where the information really comes from can help you make a more educated judgment about its accuracy.

Get a second opinion
As always, ask your doctor, dietitian, or another nutrition professional whether the information you found seems legitimate.