Popular diets: The good, the fad and the iffy

A calorie is a calorie, no matter where it comes from. Most weight-loss diets help you to restrict calories in one way or another. Ideally the new routine gets you to eat less, eat healthier and exercise more. Seems simple, right? It is, in theory.

Your weight remains stable when you eat the same number of calories you use up. So, in theory, if you eat well and exercise - and in the process burn more calories than you consume - you lose weight.

But in practice it's easy to run into roadblocks. Adopting healthy eating and exercise habits can be difficult. It takes time and effort to work physical activity into your daily routine. A good diet can be your road map to safe and effective weight management. Conversely, a poor diet can leave you spinning your wheels - or, even worse, pose serious health problems.

Components of an effective weight-loss program must include:

* A healthy diet that helps you select, prepare and eat healthy foods.
* An exercise plan that helps you increase your activity throughout the day as well as incorporate a more rigorous exercise period several times every week.

Weight-loss programs come in many forms today. Some prey on the desire for a quick fix, and some of these diets do help you lose weight quickly - at least for a while. But maintaining a healthy weight isn't something that most people can manage quickly and maintain over the long haul. It's a process, and it can be tough, but it's not impossible. If you're ready to commit to lifestyle changes - eating healthier and being more physically active - then you're well on your way to achieving a healthier weight.

Weigh the facts - avoid the fads

The benefits of living at your healthy weight are numerous. You'll look better and feel better, and you'll probably live longer, too. But it's important to find a program that's safe and works effectively. Do some research before jumping into a new diet routine. If you have questions, talk to your doctor or nutritionist.

If you're considering a new weight-loss plan, evaluate it by the following statements to see how the program holds up. If one or more of these apply, raise a red flag.

* Promises of a quick fix
* Dire warnings from a single product or regimen
* Claims that sound too good to be true
* Simplistic conclusions drawn from a complex study
* Recommendations based on a single study
* Dramatic statements that are refuted by reputable scientific organizations
* Lists of "good" and "bad" foods
* Advice given to help sell a product
* Opinions based on studies published without peer review
* Recommendations from studies that ignore differences among individuals or groups

Here, in alphabetical order, is a bird's-eye view of some popular weight-loss plans - with a look at their premises, their founders or main backers, and what the scientific evidence shows. Take a look at each and use the list to figure out which are the healthiest programs to follow. Then talk with your doctor about a weight-loss program that's right for you.