Well, as you slowly add your carbs back you will stop increasing your carbs when you BEGIN to gain. At that point you will find your critical carb level for maintaining you ideal weight (CCLM). You now know if you go over that threshhold, you will gain weight. Before you do that though, you will find your critical carb level for losing. That amount is the threshhold that divides the line between weight loss and maintenance.

I think what some people do is increase their carbs too much without finding their balance.