4. They don't go it alone.
If you're a lone wolf, it's time to join a pack. "Everybody needs some support, whether it's emotional or logistical, so you stay accountable," Hill says.
Try teaming up with family, friends, or co-workers, or sign up for a weight loss support group even if you're already at your goal weight, Kahan says. If you slimmed down with help from a dietitian or other expert, keep checking in with that person every now and then.
5. They limit their screen time.
Whether it's your tablet, phone, computer, or TV, screen time tends to be idle time. And let's face it: It's so easy to overeat while you're parked in front of a screen. So give yourself a curfew: You're only going watch or surf for a certain amount of time a day.
Consider this: The average American watches 28 hours of TV per week, but 62% of people in the National Weight Control Registry, who have all lost 30 pounds or more and kept it off for at least a year, watch 10 or fewer hours per week.
6. They step on the scale often.
Most people in the National Weight Control Registry weigh themselves regularly. In fact, research shows getting on the scales daily is a very effective strategy for those trying to maintain weight loss.
"It's not just weighing yourself that's important; it's having a plan for what to do if your weight exceeds the level you want it to be," Hill says.
In other words, you need to know how to take action promptly if you see those numbers starting to climb, whether that means trimming back on portion sizes or skipping dessert more often.
7. They eat breakfast.
Nearly 80% of people in the National Weight Control Registry eat breakfast. Breakfast isn't a magic meal. Weight loss depends on what you're eating and your overall calorie balance throughout the day.
One theory is that eating breakfast sets the tone for the rest of your day. So start out with something that gives you nutrients, not empty calories. For instance, you could have oatmeal topped with fruit and nuts, or low-fat yogurt with berries and granola, or an omelet loaded with veggies and some whole wheat toast on the side.