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.