You’ve heard over and over that you shouldn’t even try to lose weight quickly. The experts who say this insist that you can only really expect to lose a pound or two of fat per week on a diet, and anything more “must” be water weight, or worse yet muscle. Who wants to lose muscle, and what if you gain those pounds back just as fast as you lose it? A new study knocks all that logic on it’s ear.

Scientists wanted to see if there was any actual benefit in losing weight slowly or quickly. They studied 262 obese middle-aged American women who were trying to lose roughly 10% of their body weight with “a six-month lifestyle program encouraging them to reduce their calorie intake and increase their moderate intensity physical activity to achieve an average weight loss of 0.45kg per week. They were then supported for a further year with an extended care program involving contact twice a month in the form of group sessions, telephone contact or newsletters.” Keep in mind 0.45kg is roughly 0.99 pounds — right in line with current recommendations. After the first month, researchers grouped the women according to how much initial weight loss they had. “Fast” weight losers lost an average of 1.5 pounds per week, “Moderate” weight losers lost 1-1.5 pounds per week, and “Slow” losers averaged 0.5 pounds per week.

Here’s what they found at the end of the study:

• Fast weight losers lost more weight total — an average of 30 pounds in 6 months
• Fast weight losers maintained weight loss longer and were not more likely to put the pounds back on than slow losers
• Fast weight losers were 5 times more likely than the slow weight losers and 3 times more likely than the moderate weight losers to meet the goal of losing 10% of their weight in 18 months
• Fast weight losers kept better records of what they ate and ate fewer calories

The bottom line is that while for most people, rapidly losing dozens of pounds “Biggest Loser” style without direct medical supervision is not healthy, there is no point in deliberately trying to take it slow either. Not everybody can lose 245 pounds in under a year like Jared the Subway guy, certainly, but don’t panic if the pounds start to vanish just by eating right and getting some exercise.

Her take: I think there several issues at work in this study. First, those who lost weight quickly had to buy new clothes quickly too. Being able to continue fitting into the “cute new clothes” is a huge motivator to keep the weight off, particularly if you got rid of all your “fat clothes.” Fast losers also probably got complimented on their weight loss quickly too, and external validation can be an important component of both losing weight and keeping it off (say something nice to a dieter today!). Finally, I don’t think it’s any coincidence that fast losers kept better track of what they were eating and ate less. That is a behavior any dieter can emulate, as long as he or she is really motivated to lose weight.