Many Americans who are choosing a healthier lifestyle may be making choices based on some common nutrition myths. Are you one of them?

If you want to eat healthier, Good Housekeeping's nutritionist says you need to know the truth about three common nutrition myths. Myth number one: Dry roasted nuts have fewer calories than oil roasted nuts.

"But that's really not true," says Delia Hammock, R.D., Nutrition Director, Good Housekeeping Institute. "Common sense would suggest that something that is dry roasted would have a lot less calories than nuts that are roasted in oil. But, in truth, the calories are about the same. If you want to watch your calories while eating nuts pay attention to the portion size, not how they're cooked."

Myth number two: pork is fattening. Pork such as bacon, spareribs, sausage are delicious, but they're not exactly diet foods. But pork tenderloin is one of the leanest meat options. Three ounces of cooked pork tenderloin has about 140 calories. About the same as skinless, boneless chicken breast," says Hammock.

Myth number three: frozen vegetables are less nutritious than fresh. "Just picked vegetables do have more vitamins and minerals," says Hammock. "But, during storage and shipping, these nutrients decrease. On the other hand, frozen vegetables are picked ripe and they are flash frozen so they retain most of their nutrients."

One final note about that 'eight glasses of water a day' thing. Not true.

Our water requirements vary from person to person, and things like milk, juice, coffee, tea and soft drinks all contribute to our body's need.

For more information on nutrition myths, check out the October issue of Good Housekeeping or visit www.goodhousekeeping.com.