After losing weight, it's tempting to take a vacation from healthy eating. "Many dieters start slipping back into their old behaviors soon after dropping pounds," says Naomi Fukagawa, M.D., spokeswoman for the American Society for Nutrition. But there are ways to stay on track without depriving yourself. As several new studies show, by making a few minor adjustments to your regular routine, you can hang on to those hard-earned losses for good.

Weigh in Regularly

"Hopping on the scale consistently provides positive reinforcement for your healthy habits," says Meghan Butryn, Ph.D., an assistant professor of psychology at Drexel University. "It can also help you catch small gains before they escalate."

When Butryn and her research team studied the habits of adults who'd lost 30 pounds or more and kept it off for several years, they discovered that those who got on the scale consistently put on just 4 pounds in a year. However, the dieters whose weigh-ins declined in frequency gained back double that amount.

So exactly how often should you check in with your bathroom scale? Once a day, if possible. Dieters who did so were 82 percent more likely to maintain their loss over 18 months than those who monitored their progress less frequently, additional research shows. Butryn cautions that if the number on the scale rises by more than 1 or 2 pounds (an amount that could simply be due to water weight or a big meal), consider that a red flag to tweak your diet and exercise habits.

Pump Up the Protein

A study from the American Journal of Clinical Nutrition found that women who got the highest levels of protein in their diets (around 110 grams daily, or 26 percent of their calories) maintained a 14-pound weight loss for more than a year. Those who got less than 72 grams of protein per day, or less than 19 percent of their intake from protein, only sustained a 7 1/2- pound loss during the same period.

"Higher amounts of protein may prompt the release of hormones that help you feel full," says Peter Clifton, Ph.D., lead study author and coauthor of The Total Wellbeing Diet.

Rather than getting additional energy from carb- or fat-laden fare, add protein to most meals and snacks. Sprinkle kidney beans or chickpeas on your salad, switch to protein-rich Greekstyle yogurt from the regular variety, and trade your afternoon bag of pretzels for a mini cheese-and-turkey roll-up.

Strive for Five...

...fruit and veggie servings. Packing your plate with greens (as well as oranges, reds, and blues) not only helps protect you from a variety of diseases, but also keeps extra pounds from sneaking back on. A study from the Centers for Disease Control and Prevention (CDC) found that women who consumed the highest number of fruit and vegetable servings (at least five per day, not including potatoes) were 60 percent more likely to ward off weight regain than those who got fewer servings. Experts say loading up on produce, which generally has a high fiber and water content, means you have less room for other, higher-calorie foods.

Learn to Love Exercise

When the frequent fruit and veggie eaters from the CDC study combined their produce habit with moderate to vigorous exercise- getting at least 30 minutes of activity on most days of the week-they were more than twice as likely to keep the weight off than those who worked out less. "Regular workouts can help you maintain lean muscle mass, which means you'll burn energy even at rest," says Scott Going, Ph.D., a professor of nutritional sciences at the University of Arizona. Plus, exercise gives you a bank of extra calories to play with, allowing you to enjoy an occasional slice of birthday cake or a small bag of movie popcorn without gaining weight.

Eat Out Less Often

With portion sizes growing exponentially and some dishes packing more than 1,000 calories, it's little surprise that restaurant meals can sabotage your weight-loss success. You can certainly minimize the dietary damage by making healthy selections. "But preparing your own meals can be a far more effective way to ensure you're eating foods that are low in fat and calories," says Judy Kruger, Ph.D., an epidemiologist at the CDC. Ditching the drive-through can be particularly helpful: Compared with people who ate fast food at least twice a week, those who skipped it entirely upped their odds of maintaining their weight by 62 percent.

Because it's pretty unrealistic to expect that you'll never sit down at a restaurant again, Kruger suggests splitting an entrée with a friend, getting a half-size portion (if it's available), or ordering an appetizer as your meal. People who used these strategies were 28 percent more likely to stay at their newer, slimmer size than those who didn't.