The weight is over, but how do make sure you don't gain it back? Almost 65 percent of Americans are significantly or dangerously overweight. Most have lost weight at some point, only to gain it back again later. Some, however, keep it off for good.

The losing game

Losing weight is not easy, but it really comes down to simple math: burn more calories than you consume. Coming up with a winning combination of lifestyle changes to make it work for you is the hard part.

Neither cutting down on calories nor exercise alone works to keep weight loss in the long term. While people who try extreme diets do often lose weight, they usually gain it back once they start eating normally again. Very few can keep up extreme exercise schedules, either. It takes a lifetime commitment to lose weight for good.

According to Psychology Today: "More than 54 million [Americans] are dieting. Of those who successfully lose weight, 90–95 percent are unable to keep it off long-term."

Long-term lifestyle wins

Jason Olson, program manager and ACE certified fitness instructor at Lloyd Athletic Club in Portland, Oregon, says: "People think once they've lost weight, they can take it easy, skip workouts and eat donuts again. Then the weight creeps back. To keep it off permanently, people have to examine their lifestyles and continue doing whatever they did to lose weight in the first place. That means giving up bad habits and adopting new ones." Olson recommends keeping a food journal. "When you notice you're slacking off, it's very motivating to stay on track."

Regina Brooks, personal trainer at Lloyd Athletic Club, is a weight loss expert in more ways than one. She's been an ACE certified fitness instructor for 12 years, has lost 80 pounds and has kept it off for 16 years. "Most people don't really overeat," Brooks says. "They just don't eat right. In fact, many don't eat enough. They eat too many simple carbs, like bread, pasta and gravy, and not enough foods with 'chewage,' like protein, whole grains, fruit, veggies and high-fiber foods." After a lifetime of skipping meals and then overeating in the afternoon, Regina finally lost weight by adding breakfast and eating five small meals per day, along with learning to love exercise.

Exercise, exercise, exercise

While Olson and Brooks both emphasize exercise for weight loss, they're realistic about the role fitness plays in real life. Olson says: "To lose weight, you need to exercise five to seven days per week. Once you've lost weight, you can drop back to three full strength and cardio workouts per week and still maintain your weight loss." A full workout includes 30 or more minutes each of cardio and strength training.

"Women worry that weight training will bulk them up," Brooks says, "but muscle burns more calories than fat—even when you're just sitting around. Weight training also improves bone density. People can build muscle mass using lighter weights and [doing] more repetitions without ever looking like a body builder." Brooks recommends mixing up your workouts and trying new things in order to avoid burnout and boredom. "When people get bored, they quit exercising."

Keeping it off

The National Weight Control Registry (reported in Psychology Today) found four trends in the people they study who keep weight off:

  1. No matter what diet they used to lose weight, most of them now eat a low-fat, high-carbohydrate diet.
  2. Almost 80 percent eat breakfast daily.
  3. They stay very active. Several studies show that it takes the same effort as walking 4 miles or taking 10,000 steps per day to keep lost weight off. Playing sports, exercise (including cardio and strength training), gardening and housework can all play a part in getting that effort in.
  4. They keep track of their weight. Some weigh themselves daily. Others keep a food journal.

Some of the best tips in the battle of the bulge came from outside the gym:

  • Look at yourself in the mirror every day—naked.
  • Find a kind of exercise that you love and look forward to doing.
  • When you're 80 percent full, stop eating—even if you 100 percent love what you're eating.
  • Be consistent and avoid extremes (moderation!).
  • Most of the time, eat whole, nonpackaged food that's healthy.
  • Balance splurge days with extra exercise.
  • Be careful of your serving sizes.
  • Put exercise on the calendar, and keep that appointment.
  • Drink more water, and eat more protein, fruit and veggies.

Remember, simple math took the weight off. Simply living differently can keep it off.

Published on Jan. 4, 2010; updated on May 2, 2014.