I went on South Beach and lost 20 pounds ( I had reached 175 prior to the operation). I can't fathom going on South Beach while I am riding 2-3 times a week to work.
Yea, the low-carb thing doesn't work with a physically active person.

You do have to find a balance between carbs, protein, fats, and calories... to eat enough for energy... but not too much.

Otherwise... gravity works against us every year we get older. I am in my 30's.... but I certainly relish everyday I am phyiscally fit enough to ride my bike.

I can only HOPE that I will be in this good of health (as many of your ladies are!) when I hit my 50's!