AS WEIGHT-LOSS RESEARCHERS WHO’VE published hundreds of scientific papers and helped thousands of people lose weight, we’ve seen diet trends come and go–some of them more than once! Frankly, diets don’t work (that’s why there are so many of them). So why, then, are we writing a diet book?

Well, State of Slim isn’t really a diet book. Yes, we give you a step-by-step plan for eating and exercising the healthiest way. And yes, you’ll lose weight–quickly and safely. But we think you deserve more.

Typical diet books contain quick-fix plans designed to help you fit into your skinny jeans or look thinner for a one-night class reunion. They lure you with promises of dramatic results (drop 15 pounds in 15 days!). And it’s true, you can lose weight with any one of these plans–but you probably won’t keep it off. Even though you’re trying to do all the right things, the pounds inevitably will creep back on, and you won’t have a clue how to stop them. You’ll probably assume that the weight regain is your fault, feel terrible, and repeat the whole sad process with the next new diet book.

You deserve to know the real deal: Dropping pounds is only part of the picture. You aren’t overweight simply because you eat too much and therefore must “diet” to slim down. Lack of movement has played an important role as well. In fact, overeating is just as much a consequence of being overweight as it is a cause (we’ll explain this startling fact later on). Keeping weight off is a different challenge than losing weight and requires a different strategy. Our approach, which we call the Colorado Diet, tackles both aspects. It is a complete and permanent solution to your weight problem.

By now you must be wondering why we call the State of Slim plan the Colorado Diet. We both live in the Denver area, and we run the Anschutz Health and Wellness Center at the University of Colorado. But that’s not the only reason. At a time when two-thirds of the American population is overweight or obese, Colorado has bucked the trend: It’s the leanest state in the nation. Colorado has an overall obesity rate of 21 percent, and some counties have obesity rates below 15 percent. Compare this with the national average obesity rate of 28 percent, and 35 percent in the heaviest state. How do those statistics help you if you live in New York, Texas, or Iowa? Our Rocky Mountain state is beautiful and inspiring, but it’s not magical. Colorado just happens to provide an opportune place and supportive environment for people to live a lean lifestyle naturally. And our work with our patients–as well as our research with people from all 50 states–has shown that you can adopt a Colorado lifestyle no matter where you live.

Neither one of us is originally from Colorado. When our careers brought us here and we each settled into the Rocky Mountain lifestyle, we found ourselves skiing, hiking, biking, working out, and eating a healthy diet–like many of our colleagues, neighbors, and friends–and feeling healthier. (Holly’s story on page xvi will likely resonate with many of you.) At the same time, we were both involved in a research project that Jim cofounded. Called the National Weight Control Registry (NWCR), it’s a scientific database of more than 10,000 people from across the country who have dropped at least 30 pounds and maintained the loss for a minimum of a year. The average NWCR participant has lost 70 pounds and kept them off for 6 years. By studying this group, we’ve identified some key strategies that are essential to successful weight loss and maintenance. And as we learned more about what keeps people lean, we realized that our friends, neighbors, and families were intuitively following those key strategies. That’s when it dawned on us: Colorado is the sweet spot where research lab meets real life.

As scientists, we performed many research studies to examine metabolism and obesity. And the top complaint of patients in our weight-loss clinic is “My metabolism isn’t working!” When we first began our research, though, we didn’t find anything wrong with the metabolisms of overweight and obese people; their bodies burned calories at the exact rate they should. But eventually, we discovered that our patients were right. Overweight people burn calories at a normal rate, but their metabolisms are stuck in a fat-storing mode. We’ll explain this more in Chapter 2. For now, know this: You can lose weight with a broken metabolism, but you cannot keep it off.

A Colorado lifestyle creates what we call a Mile-High Metabolism. Denver is known as the Mile-High City because it sits at an elevation of 5,280 feet–exactly a mile above sea level. And with our plan, your metabolism will reach new heights.

Coloradans’ lifestyles keep their metabolisms in tip-top shape–revved up and able to easily burn whatever they eat. It all starts with physical activity. For many Coloradans, it’s not a matter of deciding whether to exercise–it’s choosing what to do, when, and with whom.

When you stop moving your body, your metabolism slows, your appetite goes haywire, and you begin eating too much of the wrong kinds of foods. The result? You gain weight and have difficulty losing those extra pounds. You just can’t be healthy and slim without regular physical activity–and we say that with decades of research behind us to prove it. We’ll show you how to incorporate an achievable, enjoyable amount of physical activity into your life–in effect, creating your own Colorado lifestyle–so that your body’s metabolism works with you to stay at a healthy weight.

Of course, what you eat is also important. Colorado cuisine can be described as fresh, flavorful, and seasonal. We eat smarter, not less. And the foods we choose to eat help keep our metabolisms revved instead of bringing it to a near stop.

In Colorado, when friends get together, they’re more likely to meet up for a hike, a bike ride, or a day on the slopes than they are to go out to a restaurant together. Certainly, exercising is easier when everyone you know is doing it and you have lots of options year-round. But it’s not just about living in the right location. It’s about attitude and approach. No matter where you live, we’ll show you how to tweak your physical and social environments and develop healthy routines and rituals so that it becomes easy to create and maintain this lifestyle forever.

To help you achieve a Mile-High Metabolism, we first give you an understanding of the skills you need to keep your weight off. Most diets aim to stop bad habits. Ours focuses on instilling good ones. The difference may seem subtle, but our research suggests that it’s anything but.

Remember how we said that losing weight requires a different approach than maintaining that loss? While you are losing weight with the Colorado Diet, you will be preparing yourself for long-term success even before you start–something no other plan does for you. There are three phases. Phase 1 will reignite your fat burners so you lose weight quickly–typically 8 to 10 pounds. Phase 2 will rebuild your metabolism. You’ll continue to drop pounds and strengthen your metabolism while your diet variety increases. In phase 3, you’ll reinforce your metabolism by finding a pattern of physical activity that keeps your Mile-High Metabolism stoked and fueled by a smart, healthy, satisfying diet. You’ll now be ready to live the Colorado lifestyle we outline in Chapter 9–forever.

We’re tired of watching people succeed in losing weight, only to regain it all within a few months. We’re tired of seeing people sentenced to a life of food restriction and deprivation. As scientists and researchers, we haven’t just theorized about the right weight-loss strategies, we’ve tested them in our clinic to see if they really work–and they do. Isn’t it time to not just lose weight but fix your metabolism so you can join the ranks of those who have succeeded?

Reprinted from “State of Slim” by James O. Hill PhD and Holly R. Wyatt, MD. Copyright (c) 2013 by James O. Hill PhD and Holly R. Wyatt, MD. By permission of Rodale Books. Available wherever books are sold.