You've probably heard of all of these: The Zone Diet, fat-burning pills, The HCG Diet, The Grapefruit Diet.

There are so many weight loss programs, products and plans out there that you'd think at least one of these "magic bullets" would actually work and droves of people would be dropping pounds. If any of them were really effective, we would be seeing the obesity trend reversing. Yet all we see is more people struggling with weight than ever.

"The focus of attention tends to be on 'the promise' of the diet, rather than the thoughts and behaviors that need to fundamentally change," says Molly Kellogg, RD, LCSW, a Philadelphia-based private practice dietitian specializing in counseling for dietitians. "For example, the person may image that being thin will make life easier and bring happiness in the form of a new partner. The weirder the diet plan, the more it seems to fit with this unrealistic idea of what losing weight will accomplish."

America spent more than $35 billion in weight loss products and services, according to a 2002 report by the Federal Trade Commission. There's obviously a battle with weight going on. At the same time, Americans spent about $580 billion eating out in the past year (says a 2010 report by National Restaurant Association). In addition, the sad news is that, according to the National Academy of Science and the Food and Nutrition Board, most dieters regain back most of their pre-dieting weight within five years.

Forget about the fat - It seems the only thing consistently being lost is dieters' money.

So, what are some ways you can tell if a weight loss product or plan will really work in the long run before you buy? The only tried-and-true method for long-term, healthy weight loss by the medical community is a combined, sustained plan of diet and exercise. And there are many creative ways to achieve this goal, packaged in different forms of weight loss plans, programs and products.

If you are not made of money and can't afford to buy pre-packaged foods for the rest of your life, and you want to be healthy, not just skinny, check out these tips. Before you reach for your wallet, make sure your weight loss plan is really in the good shape it claims to be.

• The program should not be offering pills, powders, injections or similar products that are not endorsed by weight loss physicians and/or registered dietitians, and ideally, reputable health organizations as well.

• The program shouldn't be making too-good-to-be-true promises such as "Lose five pounds in one week, guaranteed! With no exercise required!" Ask yourself, if these claims were true and good for you as well, wouldn't Registered Dietitians be using the plan or product in their weight loss businesses? Registered Dietitians are the college-educated professional authorities on nutrition in the U.S. If they do not endorse a product or plan, then that's a red flag.

• The program should have been developed by a medically trained weight loss professional such as weight loss physician and/or registered dietitian, or at least be fully endorsed by several of them.

• The program should have a good success rate of permanent weight loss in clients.

• Exercise and diet go hand-in-hand to promote permanent and healthy weight loss. The program should encourage clients to exercise and explain its many benefits and have it as part of its offerings.

• The program should consider the health you are in and medical conditions you may have had when starting, your gender, age, background, medications and more-- and be customized for these situations.

• Successful programs should instill in clients the ability to hold the reigns of healthy weight in their own hands without spending tons of money for an indefinite amount of time.

• Long term weight loss does not need to cost thousands of dollars or if you're highly motivated, even hundreds. On a side note, a reasonably priced, effective weight loss plan will save you thousands later and add years to your life.

• The program's food allowances should not be so overly restrictive so that you cannot enjoy foods from all the main food/nutrient groups such as complex carbohydrates and grains, vegetables and fruits, proteins and calcium-rich foods, for example, or be too low in calories. For most people, successful weight loss does not have to involve eating fewer than 1,200 calories a day.

• The program should not be promising extremely rapid weight loss (more than two pounds per week, which equals a deficit of 7,000 calories). Studies show that those who lose weight slowly keep it off longer.

• The program should not cause you any major health problems in the long run, either directly or indirectly.

• The right plan for you will help ignite in you a lifelong passion and commitment to your health.

• The plan will provide balance in that it will help you eat the right foods in the right amounts, and still give you enjoyment to enjoy many foods, in moderation, that are available in our lives.

• The right program for you will consider your own personal needs and desires, not only in what you like to eat (these usually do not need to be written off totally) but how you like to live your life. What is your style in smart and healthy weight loss programs? Do you need social support? Regular meetings? Do you not like cooking but would like to learn how to enjoy making very simple meals with a book, video or class, for example? Does the plan have to be fun? Very organized? Loose and casual? All online, all in-person or a mix?

• Consider consulting with or joining a program run by a Registered Dietitian who you feel you would work well with. Dietitians who specialize in weight loss understand your need for permanent success and can help you get there safely with lifestyle changes catered to your wishes.

• Find a program that fits your lifestyle, personality and needs. For example, will you be able to participate in the program's meetings when scheduled? If choosing a Registered Dietitian, pick one that fits with your learning style. If you are a lively personality, choose a program that is fun.

• Choose a plan that is endorsed by the medical community, registered dietitians and national health organizations.

• Choose a plan that doesn't carry any seen (or unforeseen) short or long-term health risks. It's not all about dropping clothing sizes - A person can be thin and very unhealthy too!

• Select a weight loss program that will help you be successful once you are off the program

• Be on the lookout for the previously mentioned red flags.