From eating cookies, cabbage soup and baby food to drinking lemon juice, maple syrup and cayenne concoctions, dieters have tried their fair share of wacky weight-loss plans. One of the newest fad diets making headlines is the Dukan Diet - a pseudo-version of the Atkins diet that's popular in France. It's a highly restrictive plan of protein-rich, low-fat meals, lots of oat bran and tons of water. Exercise requirements are light. The British Dietetic Association labeled it one of the year's worst fad diets.Though industry experts say diets are trending away from the extreme and toward sustainable lifestyle changes that incorporate healthy eating and exercise, millions will continue to fall prey to bogus fad diets. Here are five ways to spot one:It promises super-fast results.Healthy diet plans shoot for a one-half to 1-pound loss a week at most. Any faster and it's not fat you're dropping, but also muscle, bone and water.It limits food choices.Banning fat, sugar or carbs - or focusing your diet solely on one type of food, such as cabbage soup or grapefruits - is both nutritionally deficient and not sustainable. The best way to keep weight off: Eat healthy portions of a variety of foods, including protein, whole grains, fruits and vegetables.It requires specific meal combos.There's no scientific proof that combining certain foods helps you drop pounds or that eating "wrong" combos turns food to fat or increases toxin levels, as some plans claim.It includes special pills, powders or herbs.Some supplements contain laxatives or diuretics that eliminate water weight, not fat; others claim to contain ingredients that speed up metabolism, suppress appetite or block the absorption of fat or carbs - but there's no reliable science to back those claims.It skips exercise.There's no way around it: Regular physical activity - 30 to 60 minutes on most days - is necessary to lose weight and keep it off.The Doctors is an Emmy-winning daytime TV show with pediatrician Jim Sears, OB-GYN Lisa Masterson, ER physician Travis Stork, plastic surgeon Andrew Ordon, health and wellness expert Jillian Michaels and psychologist Wendy Walsh. Check www.thedoctorstv.com for local listings.