But before you start pasting gold stars onto your refrigerator door, take heed: Nutrition experts say most of us think we are eating a lot better than we actually are.

"It's easy to buy into some pretty popular nutrition misconceptions -- myths and half-truths that ultimately find us making far fewer healthier food choices than we realize," says New York University nutritionist Samantha Heller, MS, RD.

To set the record straight, Heller and two colleagues from the American Dietetic Association gave us the dish on seven nutrition mistakes you probably don't know you're making -- along with sure-fire ways to avoid them.

Mistake No. 1: Assuming your choices are better than they actually are.

From fruit juices to canned vegetable soup, breakfast muffins to seven-grain bread, it's easier to think your food choices are healthier than they really are, experts tell WebMD.

"If a label says 'Seven-Grain Bread,' it sounds pretty healthy, right? But unless that label also says 'whole grains' it's not necessarily going to be the healthiest bread choice you could make," Heller says.

Likewise, she says many folks think that eating a can of vegetable soup is as nutritious as downing a plateful of veggies -- not realizing how few vegetables are inside, and how much of the nutrients are lost in processing.

Another common mistake: Substituting fruit juices for whole fruits.

"Are fruit juices healthier than soda? Yes. But they are also concentrated sources of sugar that don't give you anywhere near the same level of nutrients you get from whole fruits," says Bonnie Taub-Dix, MA, RD. What's more, says Taub-Dix, if you're trying to lose weight, you won't get the same sense of fullness from a glass of juice that you will from a piece of fruit.

"Instead, you'll just take in a whole lot of calories -- and still feel hungry," Taub-Dix says.

The solution: Whenever possible, eat whole, fresh, and unprocessed foods. Even when you eat them in smaller amounts, you're likely to get a well-rounded group of nutrients. When buying packaged foods, put in at least as much time into reading labels and selecting products as you do when choosing a shower gel or shampoo.

"Don't just assume a product is healthy -- even if it's in the health food section of the supermarket," says Heller. "You've got to read the labels."

Mistake No. 2: Being confused about carbs.

A national fascination with low-carb diets has many Americans eliminating carbohydrates from their eating plans in record "grams." But before you reconstruct your personal nutrition pyramid, there's something you should know.

"There are carbs that are very, very good, and some that are less good, but your brain and body must have some carbohydrates every day," says Heller.

Moreover, because complex carbohydrates (those rich in whole grains and fiber) keep you feeling full longer, they also help you to eat less -- and lose more!

But eliminating this important food group isn't our only carb-related mistake. According to dietician Rachel Brandeis, MS, RD, just as troublesome is the belief that all no-carb or low-carb foods are healthy, or that you can eat them in any amount.

"Much like the low-fat diet craze, where everyone thought that if a meal had no fat, it had no calories, similarly people have come to believe that if it has low carbs you can eat as much as you want and not gain weight," says Brandeis. "And that is simply not true." Eat enough of anything, she says, and you'll gain weight.

The solution: Experts say you should never cut any food group out of your diet -- including carbohydrates. Equally important, says Heller, is to learn which carbohydrates give you the biggest bang for your nutritional buck.

"It's a lot harder to run amuck when you are including carbohydrates like fresh fruits and vegetables and whole grains in your diet," says Heller.

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Mistake No. 3: Eating too much.

Whether you're filling your plate with low-fat, low-carb, or even healthy, nutritionally balanced foods, overestimating how much food your body needs is among the most common mistakes, experts say.

"Many people believe they should feel not just satisfied after a meal, but stuffed," says Heller. "I think many of us have lost touch with the sensation of having had enough food."

Adds Taub-Dix: "People also tend to believe that they can eat larger portions if all the food on their plate meets the guidelines of their current diet -- such as low-carb or low-fat -- and that, of course, is also not true."

The solution: Remain conscious of portion sizes. Weigh and measure standard portions, at least at first, so you'll know what the amounts should look like. And, says Brandeis, "never use restaurant portions as your guide -- they super-size everything."

Mistake No. 4: Not eating enough -- or often enough.

While overeating and undereating may seem like contradictory nutrition mistakes, they are related.

"If you don't eat at regular intervals throughout the day, you risk disrupting your blood sugar and insulin levels, which in the end can promote fat storage and lower your metabolism -- both of which lead to weight gain," Brandeis says.

The solution: Eat something every four hours and never let yourself "starve" from one meal to the next, Brandeis says.

Mistake No. 5: Taking too many supplements.

"People tend to forget that a vitamin pill is a supplement -- it's meant to complement your diet, not act as a stand-in for the foods you don't eat," says Heller. What's more, she says, taking too many vitamins can end up sabotaging your good health.

"Every vitamin and mineral and phytochemical in our body works in concert with one another, and it's easy to knock that balance off if you are taking concentrated doses of single nutrients, or even groups of nutrients," says Heller.

Bradeis cautions that any diet plan that claims you must take a high-potency supplement to meet your nutritional needs should send up a red flag.

"It means that eating plan is not healthy," says Brandeis, "and it also means you are going to miss out on the synergistic health effects that can only come from whole foods -- including not only helping you to feel fuller longer, but also preventing cellular breakdowns important to preventing disease."

The solution: Both experts recommend taking no more than one all-purpose multivitamin daily. Don't supplement your diet with individual nutrients without the guidance of your doctor, nutritionist, or other health expert. Keep in mind that the sales clerk in the health food store is usually not a health expert.

Mistake No. 6: Excluding exercise.

While most folks believe nutrition is all about food, Brandeis says it's also about how your body uses food -- and that's where regular exercise comes in.

"Without adequate exercise, you cannot maintain a high enough metabolic rate to burn your food efficiently," says Brandeis. "A pill can't do that for you; foods alone can't do that for you. Exercise is the only way to achieve it."

The solution: Make exercise a regular part of your life. And don't get hung up if you can't do it at the same time every day. If you miss your routine in the morning, don't wait until the next day and try to do twice as much. Instead, try to fit in some exercise -- even if it's just a little bit -- every day, says Taub-Dix.

Mistake No. 7: Believing everything you read about nutrition and weight loss.

"Just because someone writes a diet book or a nutrition guide does not mean they are an expert," cautions Brandeis.

If you're turning to a book for guidance, she says, "look to the author's credentials and ask yourself: Is this person a dietician; do they have an advanced degree in nutrition? Or are you buying this book because it's written by a celebrity who you think looks good?"

Even if an "expert" is behind your nutrition or diet plan, Brandeis says, it's important to make sure the plan is based on solid research.

"Has the plan been tried on 20 people or 200 people? Have the results been published in a peer-reviewed medical journal -- or is it based solely on anecdotal reports? These are things that I fear many people don't pay attention to before paying attention to what is being said -- and that is a huge mistake," says Brandeis.

Perhaps even more important: Experts say there is no one diet or nutrition plan that is right for every person.

Brandeis tells WebMD that dieters need to stop blaming themselves when a plan doesn't work for them. It's not them, she says. It may not even be the plan. "It's just not the correct match," she says.

The solution: Before following a particular diet or nutrition plan, check the credentials of the author or creator. Look for plans that are backed up by published medical data, and supported by the opinions of many experts in the field.

By Colette Bouchez
Published Tuesday, January 11, 2005.
Reviewed By Kathleen Zelman, MPH, RD, July 25, 2007.
Medically updated July 25, 2007.

SOURCES: Samantha Heller, MS, RD, dietician and nutritionist, New York University Medical Center, New York City. Bonnie Taub-Dix, MA, RD, CDN, director, medical nutrition therapist, BTD Nutrition, New York City; spokeswoman, American Dietetic Association. Rachel Brandeis, MS, RD, spokeswoman, American Dietetic Association, Atlanta.