By Meredith Melnick | @meredithcm | July 6, 2011

Losing weight is hard enough. Keeping it off is even harder. Now a new study by researchers at Penn State suggests that the techniques that work for losing weight aren’t necessarily the same as those that help keep you slim.

First, the researchers surveyed more than 1,100 people who had achieved significant weight loss and maintained it. The researchers identified 36 weight-loss and weight-maintenance practices that at least 10% of the group used.

Then the researchers conducted a national telephone survey of overweight people (with a BMI of 25 or higher) who had tried to lose weight and keep it off with varying success: about 11% reported successfully losing weight, defined as losing at least 10% of body weight, and 21% were able to maintain that loss for at least a year. The researchers asked them how frequently they employed the 36 previously identified techniques: “often or very often” or “seldom or never.”

The survey found that people who lost weight successfully did so by participating in weight loss programs, cutting back on sugar and carbs, eating healthy snacks, not skipping meals and participating in different types exercise.

Not all techniques that led to initial weight loss were associated with weight maintenance, however. Continually switching up an exercise regimen helped people lose weight, for instance, but those who kept weight off tended to stick with a consistent exercise program. That may be because experimenting with a variety of workout routines may help people as they’re trying to lose weight, but once they’ve found what works for them, they tend to stick with it for maintenance.

The study noted four strategies that were associated with weight maintenance but not loss:

* Eating a diet rich in low-fat proteins
* Following a consistent exercise program
* Rewarding yourself for dieting and exercising
* Reminding yourself of why you need to keep weight off

“It seems somewhat similar to love and marriage,” study author Dr. Christopher Sciamanna, a professor of medicine and public health sciences at Penn State College of Medicine, told WebMD. “What gets you to the altar is likely to be quite different than what keeps you married in the long-term. [And] not recognizing this transition and adapting with different practices will also get you in trouble.”

Still, say many nutrition and obesity experts, the basic underlying principles of weight loss and maintenance are the same: you have to eat a healthy diet and increase your exercise. People who lose weight and keep it off tend to eat significantly healthier foods and do a lot more exercise than the average American.

But what may shift between weight-loss and maintenance phases is a person’s mindset: rather than focusing on actively losing weight in the short term, people have to start focusing on long-term, permanent lifestyle changes and behaviors, if they want to maintain the weight that’s been lost. The key to success, experts agree, is motivation, not necessarily the particulars of your weight-loss program.

The study had some limitations, including the fact that respondents’ weights and behaviors were all self-reported. The study appears in the American Journal of Preventive Medicine.