No need to count every last calorie. These women shed major pounds by making one simple lifestyle change. Here's how you can, too.

Getty ImagesAfter yo-yo dieting their way toward slim and back again, these women had tried every weight-loss trick around: skipping meals, taking diet pills, slashing calories. But—no surprise—none of them worked.

It wasn't until they made a simple but pivotal change that they were able to lose for good. Unwittingly, they stumbled upon a weight-loss secret backed up by recent research: The key to transformation boils down to committing to one small change, which then triggers a cascade of other healthy behaviors.

"These 'keystone habits' are powerful because they influence our opinion of ourselves," says Charles Duhigg, a New York Times reporter and author of The Power of Habit. When you start working out, for instance, you might begin to see yourself as self-disciplined—and self-disciplined people don't succumb to cheeseburgers.

To identify your keystone habit, focus on something that's always intrigued you but that you've resisted in the past. Once it becomes routine, don't be surprised if it creates a wave of positive transformation. It did for these five women!


BeforeCourtesy of Jennifer Drummond"I walked my dog every day."
Jennifer Drummond, 40, office manager (Oakley, CA)

Height: 5'11"
Weight before: 175 lbs
Weight after: 142 lbs

"My nightly routine used to consist of eating dinner, then watching TV. But one night, my dog was so agitated, I decided to take her for a walk. It was just a mile, but it seemed to calm her—and me, too. So I went again the next night, and the next, not realizing that by walking her every night for a month, I'd lose 10 pounds.


AfterCaroline Schiff

"I was so proud of my unexpected slim-down I started cutting portions at mealtime. Instead of seven ounces of chicken breast, I'd have four; rather than a whole plate of pasta, I'd have two ounces with lots of veggies.

"A few months later, I'd dropped five more pounds. Spurred on to take it to the next level, I bought a workout DVD and within six months I'd lost 33 pounds, total. Now, almost three years later, I've kept the weight off, plus I have more energy. I couldn't be happier!"

Why it worked: "De-stressing was as key for Jennifer as burning calories," says Kelly McGonigal, PhD, author of The Willpower Instinct. "The relaxation from walking her dog likely helped her lose initially by reducing cravings and increasing her energy."

Make it work for you: Line up an exercise buddy to go for that walk or run, whether it's your dog or a friend. When you have someone else relying on you, you're more likely to stick with it.

Next Page: I played video games [ pagebreak ]


"I played video games."
Dana Cohen, 41, stay-at-home mom (Denver, CO)

Height: 5'9"
Weight before: 220 lbs
Weight after: 145 lbs

"At my heaviest, my feet would become unbearably painful if I stood much longer than a minute or two. I couldn't even unload the dishwasher without sitting down! But I had five children under the age of 9; where would I find the time to tackle a diet?

"That's when I decided to try the EA Sports Active fitness programs on the Wii system that my husband and I had just bought for our kids. I knew the programs would be plenty challenging, but more important, they were right there in my home, so I had no excuse for slacking off. Soon, it became a fun family project to get Mom back to 'normal'—i.e., less tired and irritable. After three months, I'd lost about 30 pounds. I felt so awesome, I moved on to P90X, a more intense workout program, and then another. It was such a feeling of accomplishment I went on to become certified as a personal trainer—and lost the last 10 pounds in the process. Knowing I can control my health and slow down the effects of aging is so empowering."

Why it worked: "Studies show that if an exercise facility is not convenient, people will drop out," says Walter R. Thompson, PhD, exercise physiologist and professor of kinesiology and health at Georgia State University. "Home is as convenient as it gets."

Make it work for you: Instead of changing your life to fit in an exercise regimen, fit exercise into your routine: Start by DVR-ing workouts on TV.

Next Page: I quit smoking [ pagebreak ]


Istockphoto "I quit smoking."
Jen Small, 38, stay-at-home mom (Biddeford, ME)

Height: 5'7"
Weight before: 262 lbs
Weight after: 145 lbs

"Doing things because other people wanted me to—whether it was losing weight or giving up cigarettes—had never been enough of a motivator for me. But when my husband and I began thinking about starting a family, I knew I needed to improve my chances of having a healthy pregnancy, so—with the help of a smoking cessation aid—I gave up cigarettes.

"Eager to do whatever it took to keep my mind off them, I joined a gym. At first, all I could do was walk on the treadmill. I began recording each workout in a notebook, so I could chart my progress—and stay motivated. Four months later, not only was I still nicotine-free, but I'd lost 30 pounds, too. Then I found out I was pregnant—faster than we had intended—but it inspired me not only to stay active but also to eat healthier.

"Fast forward to 2009, a year after my daughter was born. Still off cigarettes and down 60 pounds on the scale, I signed up for a 5K. As I fell in love with racing, my body got smaller, and my fitness goals grew to include training for a triathlon. Years ago my idea of a triathlon would have been a six-pack, Chinese takeout, and trashy TV. Now the sport I couldn't imagine ever being able to do fills so many needs in my life, like challenging myself and staying healthy for my little girl."

Why it worked: "Sometimes we need to be pulled by a life dream much bigger than fitting into skinny jeans," McGonigal says. "Jen found a transformative vision for herself. The dream of becoming a mom inspired her to make the one change that led to all the others."

Make it work for you: Ask yourself where you want to be in one year, five years, or 10 years. What could you do now to help make that vision possible? Start with the step that seems doable, and use your end goal to propel you.

Next Page: I tried Zumba [ pagebreak ]


Getty Images"I tried Zumba."
Cindy Sorano Rifkin, 43, Medicare specialist (Marlboro, NY)

Height: 5'5"
Weight before: 245 lbs
Weight after: 193 lbs

"I was never able to find an exercise that I could stick with until I discovered Zumba two years ago. After four classes, I was addicted!

"At first, I didn't see results on the scale, but I was having so much fun I didn't let that discourage me. By the end of an eight-week session, my clothes were practically falling off, so I kept going, progressing to three or four classes a week.

"Eighteen months later, I'd dropped 40 pounds, but even more exciting than that, I'd reshaped my body in places I never thought possible—my hips and waist have never been so in proportion. Plus, now I can shop anywhere—not just big-girl stores. I always had plenty of energy, but now I'm like the Energizer Bunny."

Why it worked: It's easy to get caught up in what you think you should be doing (your friends are all runners, so you should be, too). But the key to sticking with exercise is to find an activity you actually enjoy. "There was something about Zumba that spoke to Cindy, so she tried it and ended up liking it," McGonigal says.

Make it work for you: Pick a workout or sport you feel drawn to and commit to just one session. Don't like it? Try something different until you find a good fit. Revel in the first little victories—from simply finishing a class without quitting to finding that the jeans you haven't been able to squeeze into are now a perfect fit.

Next Page: I signed up for a half-marathon [ pagebreak ] "I signed up for a half-marathon."


AfterAlex Miller Jennifer Roe, 40, documentary filmmaker (Lodi, NJ)

Height: 5'5"
Weight before: 200 lbs
Weight after: 144 lbs

"A few years ago, I was following a self-help book's recommendation to make a list of 100 life goals, pick one, and work toward it. Thinking of a friend who'd just competed in a half-marathon, I listed 'run a marathon'—never mind that I hated running! Soon after, I registered for a half-marathon, never dreaming that small, impulsive move would change my life.

"My first day of training, I hated it as much as I knew I would, but since I was already registered for the race, I signed up for a walk-to-run program to help me work up to 30 minutes by the end of 30 days. Just completing that program inspired me to keep going; soon enough, I was logging serious miles. And I started to look at food not as a source of pleasure, but as a source of fuel: I could run farther if I had oatmeal for breakfast, so that's what I ate.

"One year and almost 60 pounds later, I ran my first marathon. I've since completed six half-marathons and countless 5Ks. Now, I'm teaming up with 11 other people who've lost major weight to run a 200-mile relay race and film a documentary, From Fat to Finish Line, about this amazing journey."

Why it worked: "Jennifer set a goal that changed her identity: The decision to run a race, and those first small accomplishments made her feel like an athlete," McGonigal says. "So often we come to eating or exercise changes from a place of shame. Choosing to run a race changed the frame; it was about celebrating her potential, not fixing what was wrong."

Make it work for you: Adopt a long-term goal (like competing in a race), then break it up into less-daunting, short-term ones. Find others who have the same dream and keep each other plugging away. Remember: You can do it.