What may matter most when you're trying to lose weight is how consistently those pounds come off in the first weeks of dieting, a new study shows.

Researchers at Drexel University in Philadelphia found that people who dropped about the same amount of weight week after week at the beginning of a new regimen were more likely to be successful in the long term, compared to those whose weight loss varied weekly.

The study, published in the journal Obesity, involved 183 overweight or obese men and women who were following different weight-loss plans. The researchers looked at the number of pounds the participants lost from week to week during the first 12 weeks of their various programs. Then they compared the pattern of weight loss to the participants’ weights after 12 months and again at 24 months.

“No matter which program they were on, those who were able to lose roughly the same amount of weight each week early on did better long term than those whose weight loss fluctuated during those initial weeks,” says study co-author Michael Lowe, Ph.D., a clinical psychologist and professor in the department of psychology at Drexel University.

For example, if two dieters each lost 20 pounds in 12 weeks, the one who did it by steadily dropping a pound or two a week stands a better chance of maintaining that loss (and possibly losing more) than the person who dropped 4 pounds in one week, and then gained a pound the next, lost 3 the week after, and so on. 

“This is the first time this kind of relationship has been shown,” says Lowe. “We’ve always known that people take off weight in their own way. Some seem to lose roughly the same amount each week, while others bounce around more. We’ve never known if that variability impacts long-term success. This research says it does have something to do with it.”  

It’s not clear why weight-loss fluctuation would affect the long-term outcome, Lowe says. The researchers investigated whether emotional eating and food cravings might explain the variability in weekly weight loss, but were not able to find a connection. 

“We have done two other studies with people who are in a healthy weight range [they’re not trying to drop pounds] where we’ve shown that those whose weights vary more week to week tend to gain more weight in the long term,” says Lowe.

It’s possible that changes in hormones that affect appetite or metabolism may be to blame but more research is needed.  

How to be a Good Loser

“This study seems to show that slow and steady wins the race,” says William H. Dietz, M.D., Ph.D., chair of the Sumner M. Redstone Global Center for Prevention and Wellness at George Washington University.

Dropping as little as a half pound each week may not seem encouraging when some diet plans promise much bigger and faster weight loss. But, explains Drexel University's Lowe, it’s unlikely that you could continue to lose a large amount of weight week after week.

“It’s far better to lose less weight and do it consistently over time,” says Lowe. “Weight loss, to really be helpful, has to be maintained.”

The secret to success on the scale? It sounds simple, but you have to find a healthy way of eating that you can stick with, says Lowe.

“It’s better to approach it as, ‘what can I realistically achieve not only this week but every week,’” he says.

So that means, for example, avoiding those diets that severely restrict calories, require you go very low-carb, or cut out entire food groups. Such approaches, he explains, are just hard to sustain.

Keeping your eating habits similar from day to day may also be important.

“Maybe you eat in the same situations, at roughly the same time, and you eat a narrower range of foods and it becomes routine,” says Lowe.

In contrast, tactics such as having a “cheat day” or following your plan during the week and eating what you want on the weekends, for instance, may give you too much food flexibility.

“We know that the more variety you’re exposed to, the likelier you are to consume more calories,” says Dietz.

Being prepared will help you stay on the path to weight loss, too. Perhaps you bring a lunch to work daily or prep meals every Sunday night so you know what you’ll be eating most days.

“The more you plan ahead, the less susceptible you are to momentary influences that might get the better of you,” says Lowe.

He also recommends weighing yourself every few days so you can quickly make changes if you start to see the number on the scale creeping up instead of going down.