So what actually works for weight loss?

At the individual level, some very good research on what works for weight loss comes from the National Weight Control Registry, a study that has parsed the traits, habits, and behaviors of adults who have lost at least 30 pounds and kept it off for a minimum of one year. They currently have more than 10,000 members enrolled in the study, and these folks respond to annual questionnaires about how they’ve managed to keep their weight down.

The researchers behind the study found that people who have had success losing weight share a few things in common: They weigh themselves at least once a week. They restrict their calorie intake, stay away from high-fat foods, and watch their portion sizes. They also exercise regularly.

But note: These folks use physical activity in addition to calorie counting and other behavioral changes. Every reliable expert I’ve ever spoken to on weight loss says the most important thing a person can do is to limit calories in a way they like and can sustain, and focus on eating more healthfully.

In general, diet with exercise can work better than calorie cutting alone, but with only marginal additional weight-loss benefits. Consider this chart from a randomized trial that was done on a group of overweight folks: The group that restricted calories lost about the same amount of weight as the group that dieted and exercised, though the exercisers didn’t cut as many calories:

If you embark on a weight-loss journey that involves both adding exercise and cutting calories, Montclair’s Diana Thomas warned not to count those calories burned in physical activity toward extra eating.

“Pretend you didn’t exercise at all,” she said. “You will most likely compensate anyway so think of exercising just for health improvement but not for weight loss.”