3. Expensive supplements should not be essential.
Go ahead and take a multivitamin as a health insurance policy, but forget about gobbling down high-priced supplements that claim to burn fat or block the absorption of fat for faster weight loss. Most of the popular weight-loss supplements make claims that stretch the truth to its breaking point. Even supplements that may show promise in the laboratory are no substitute for good nutrition and adequate exercise.

4. No effort means no effect.
Though you may not want to hear it, realistic, long-term weight loss takes some work on your part. That means limiting your intake of high-sugar, high-fat, high-calorie foods and exercising regularly. You'll lose weight more slowly, but you'll stay healthy and keep the weight off. Any product or plan that tells you otherwise is attempting to sell you a fantasy. Run, do not walk, away from a plan that claims effortless weight loss.

5. Anything that sounds crazy probably is.
Pills that wring fat cells dry. Foods that burn off more calories than they contain. Eating based on your blood type. All are assertions made by a popular diet now making the best-seller rounds. And all are absolutely unfounded and ridiculous. Remember, if it sounds too good to be true ... well, you know the rest.

Got a fitness question or comment? Post it on the Fit by Friday message board!