"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.
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.
Published January 11, 2005.
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.
Last Editorial Review: 7/12/2005