If you were to stop 10 random people on the street and ask, "What should a person do if he wants to lose weight?" chances are that most would respond, "Go on a diet." This is our cultural solution to our national obesity problem. And it's making us fat.

Melinda Johnson

A recent study published in the Journal of Obesity demonstrated that normal-weight teenagers were more likely to be overweight 10 years later if they thought of themselves as overweight to begin with. This is not a new observation. Earlier studies, such as one published in the Journal of the American Dietetic Association, identified the same problem: Kids who feel fat are more likely to be fat years later.

Please pause a moment to soak this in: If you think you're fat, you're likely to make yourself fat. But why?

There are several theories; one, for example, blames stress hormones. When we're under any kind of stress, our body releases certain hormones to help us quickly deal with the situation—whether it's running out of a burning building or fighting off an attacker. However, these hormones can wreak havoc on all kinds of normal body functions, especially if we're under constant stress (such as feeling fat and struggling with body image). They disrupt sleep, alter our metabolism, and even signal to our body to lay down belly fat.

Another theory points out the flaws of "dieting." While there are all kinds of weight-loss diets out there, the one thing they all have in common is this: Most people who go on a weight-loss diet end up gaining the weight back, and many people end up gaining back even more weight than they lost. The root problem, according to many health professionals who rally against dieting, is what is termed the "diet mentality." The diet mentality is created by the act of dieting itself, and is basically a self-destructive pattern of thinking and behaving.

Here is the diet mentality at work: Have you ever gone to dinner with a friend, who ordered wings because tomorrow was the start of her diet? Or, have you ever heard someone say they were going for ice cream because they "earned" it—by going to the gym that day? Maybe you've been on a diet and found yourself dreaming about those foods that were restricted, when you never even gave them a second thought in the past. Dieting creates a perfect storm of restrictive eating patterns that cannot be maintained, along with feelings of shame and guilt. Eventually, most dieters fall off the wagon, which leads to weight gain.

So, what's a person to do? How do we stop "thinking" ourselves fat?

One solution is to flip the research on its head. What if we decide to think we're healthy? Would we be more likely to be healthy?

That's the mission of a movement called Health at Every Size (HAES). Instead of focusing on a number on a scale, HAES focuses on what we can do today to be healthy in the body that we're in, and let the numbers fall where they may. A brisk walk is healthy, whether it moves those numbers or not. Fresh, healthy food nourishes any body—fat, skinny, or in between. This idea that we should treat our body differently, depending on our weight, is ridiculous, and our body rebels against it.

Is there research behind this? You bet. One interesting study found that hotel maids lost weight when they learned that the work they were already doing was actually a good form of physical activity. In other words, once the maids thought they were doing something healthy, they became healthier.

If you think you might be stuck in the diet mentality, try for just a day to step into the HAES mentality: Do what you can today to take care of your body, and send those fat thoughts packing.

Hungry for more? Write to eatandrun@usnews.com with your questions, concerns, and feedback.

Melinda Johnson, MS, RD, is Director of the Didactic Program in Dietetics and lecturer for the Nutrition Program at Arizona State University, and a Spokesperson for the Academy of Nutrition and Dietetics. Follow her on Twitter @MelindaRD.