For some reason, I don't think I'll ever believe I've reached an ideal weight. I'm right where I need to be -- this calculator says my healthy weight range is 118 to 159 pounds, and I fall at 135. But for some reason, I always believe I should be smaller. Maybe it's the evil media, spotlighting rail-thin celebrities who make my 135 seem 20 pounds overweight. Regardless, what I need to be, say experts, is happy -- happy that my weight is normal for me. That's all that really matters, after all.

The truth about weight is that what we determine to be ideal may not be what is actually ideal for our bodies. It's kind of like body temperature. It's programmed to stay around 98.6 degrees. Our weight works on the same premise -- it's naturally regulated to stay within a range of 10 to 20 percent. This is our "set point," says Thomas Wadden, PhD, director of the Center for Weight and Eating Disorders at University of Pennsylvania Medical School. It's all based on genetics -- and diet and exercise too. It's difficult, but possible, to change eating and exercise habits to lower your set point. It just takes some hard work -- one estimate is that maintaining a 10 percent loss for six months to a year helps your body adjust to the lower weight and thus reset the set point. Just as I'm sure I may never reach an ideal weight, I'm not sure I'll ever meet this 10 percent loss either.

I've done just about everything I can to reset my clock over the past year or so. I've cleaned up my diet, and I've committed to almost-daily vigorous exercise. And here I sit -- at 135 pounds. It's less than I once weighed before revamping my lifestyle. It's just not what I'd call ideal. Happy? Yes, I'm happy. Happy enough that I'm not willing to reset my clock anymore. How about you? Is your weight ideal? And are you happy with it?