I did a quick check of the eponymously named web site Rules of Thumb for one about cycling. The closest I found was #2250: "An ideal weight for an endurance athlete, in pounds, is twice his height in inches." Being 5'11" that would make my ideal weight 142 lbs. This leads me to #3042, "The Two Keys to Dieting: Consume less and/or metabolize more. Any diet plan, supplement or gadget will only help you do one of these two things. Ultimately, you can save a lot of frustration and money by doing nothing more than consciously and continually choosing to eat less and get more exercise."