Cyndy - I don't know the answer to your question for sure, but my guess is that this is more of a problem for those of us who have lost a lot
of weight and are maintaining. Dr. Leibel's talk was about the metabolic effects of weight loss on the 'reduced obese' and there isn't any way that you can be considered obese at 140 pounds!
The bottom line on maintenance is that it's an individual, trial-and-error process. All the numbers and statistics and metabolic calculators are based on group averages. So your mileage may vary, as they say! When you reach your goal weight and are ready to maintain, my suggestion is to gradually add in small amounts of calories (while maintaining your exercise routine), monitor your weight regularly, and see how that affects your weight. That's really the only way to discover what's going to work for YOU, Cyndy.