The recommended speed limit for weight loss is 1 to 2 pounds per week. But the scientific research doesn't support it, found David B. Allison, PhD, who directs the Nutrition Obesity Research Center at the University of Alabama at Birmingham. In a recent article for the New England Journal of Medicine that busted myths about obesity, Allison cited studies that challenged the take-it-slow rule. One of these compared people who drastically cut their calories and dropped weight rapidly with people who cut fewer calories and took longer to lose, and found that both groups had the same success in keeping the weight off over 18 months.
A better way to think about it: If you follow a balanced, nutritionist-recommended eating plan for a few weeks and drop more than the recommended amount in the first few (say, 3 or 4 pounds a week) feel psyched instead of worried you may be losing too quickly. (But this shouldn't be seen as a reason to try that powdered-drink plan you've heard can help you lose 10 pounds in the time it takes your manicure to chip; nor should it tempt you to starve yourself. Fad diets and fasts are unhealthy and unsustainable.)
Next: Weight loss advice you haven't heard before