In another post I said that one gram (0.035274ounces) is insignificant because I could spit and loose that much weight. It got me to thinking, what is significant? My base weight is sometimes about 17 pounds on a multi-day backpacking trip. I loose a pound of food each day, but really don't notice it each day. I also add and subtract at very least a pint of water during the day and I can't say I can tell the difference in the pack weight or my endurance. I know it takes energy to move weight up hill and that more weight stresses you muscles and joints with each step. However there must be a point where it is reasonable to add a little weight without it affecting (or effecting, I never know which word is right) your endurance or speed. If my body weight is 180 and pack weight 22 lbs. then a whole pound is only (1/202) one half of one percent.
It is only interesting because often I am trying to decide which item I should take and have to make a decision based on weight and necessity (or comfort). For example, my Esbit stove set up is lighter than my Pocket Rocket gas stove and canister, but the latter is certainly more convenient, IMHO.