There's so much weight-loss info on this board, I thought I'd throw my question out there in hope there'd be info on the opposite end of the spectrum.

I'm one of those 'lucky' folks who has a very high metabolism. When I was fairly active, I had an average weight of 108#, which is pretty slim for my 5'4" frame, and was described by my ex as being 'emaciated' and my current as 'sorta sickly model-ish'

Through the virtues of no longer having crippling stomach ulcers (eating more) and somewhat sedentary jobs (call centers and security dispatcher) I managed to get up to 130, and after biking a bit dropped back down to 125 but a solidly-muscled 125. I know the more muscle mass one has, the more one tends to burn fat, and the higher one's metabolism tends to be... and don't get me wrong, I like the toned, lean look... but...

My question is this-
How can I adjust my diet to get the calories/carbs/fats/proteins to maintain a 'healthy' appearance and still have fun putting miles and miles on my legs and bike? I guess last year when I was biking everywhere, I looked 'sickly' thin, with ribs showing etc, despite eating everything in sight.

Help!

If it helps, I've never been diagnosed with hyperthyroidism, or any other hormonal issues, and I've always been a little stringbean, 'til I decided to take up softball and weightlifting... and biking... then a muscled stringbean.