Americans spend billions upon billions of dollars every year trying to get in shape. We try weight loss diet after weight loss diet, only to fail miserably, or lose a little and then gain it back once we stop the diet. We’ve all heard the advice that “diets don’t work,” but what DOES work? Is there really a healthy weight loss diet we can start today and stay on– reasonably–forever?

There is no simple answer to this question. There is so much confusing research and so many conflicting studies that people don’t know where to turn. Every book that comes out claims to contain the latest and greatest weight loss diet. Every guru you see on TV says they have the secret. But it seems that every time you try something new, you end up disappointed.

So, when you need a weight loss diet, what should you look for? There are a few basic principles that everyone should keep in mind when searching for a weight loss diet. Let’s mention them briefly.

First, many experts would probably agree that the solution to America’s weight problem can be summed up in one phrase: calories in, calories out. Speaking strictly about weight loss (not necessarily about health), in order to lose weight you must burn off more calories than you consume. Every pound equates to 3500 calories. So even if you consume 2000 calories every day, if you don’t burn off 2000 or more, you’ll gain weight. If you consume 1500 calories and burn off 2000, you’ll lose weight. It sounds simple, but as anyone who’s ever tried (and failed) to lose weight can tell you, it isn’t that easy! People have varying opinions on how your weight loss diet should go about achieving the proper calories in / calories out ratio, but calories certainly do matter when you’re on a weight loss diet.

Second, look for something that makes good nutritional sense to you. A weight loss diet that promises a 10-pound loss in a weekend might sound great, but if you achieve that loss by consuming only some special juice or lemon water for three days, you’re probably smart to give that program the heave-ho. A good weight loss diet will allow you to consume fewer calories without losing vital nutrients or risking your health. And any weight loss diet that works that quickly and requires such drastic measures will likely result in weight GAIN over the long haul.

Third, any weight loss diet or program you go on should encourage exercise. If they tell you that exercise is not required, they’re not looking out for your health. Even when you’re not on a weight loss diet or trying to get into shape, exercise is good for you and beneficial in too many ways to count. Some exercise, even a little, is better than none at all. Any weight loss diet that encourages or promises substantial, “healthy” weight loss without exercise is better left alone.

Basically, look for a program that isn’t too extreme. You need a weight loss diet that you can stick with–at least most of the time. Beware those lofty promises of miraculous losses, all while eating ice cream and sitting on the couch. A weight loss diet that’s worth trying will require some work. It will ask you to make some modifications to your current lifestyle, but without sacrificing your health.