First of all, congratulations on your weight loss success up to this point. Your question is a complicated one.
While it's possible, it's less likely for you to keep it off (or lose more) if you don't remain vigilant of your intake by counting calories. It's similar, in theory, to the use of pedometers or regular weigh-ins as a means of reinforcing a behavior. Research shows that the people most successful at keeping weight off over the long-term do continue to count calories. They also exercise more than you'd think on a regular basis. And step on the scale more often.
One way to avoid strict calorie counting is to control what you eat at certain meals (typically breakfast or lunch) by consuming a meal replacement such as Ensure or Slim Fast shakes. These products are nutritionally balanced and come in a variety of formulations. A meta-analysis (essentially a summary of all previous work) published in the International Journal of Obesity in 2003 concluded that the evidence is in favor of partial meal replacements as being effective in long-term weight loss.
The bottom line is you'd be best served by continuing whatever has worked for you to this point. If counting calories keeps you in line, then keep counting!
