I have to disagree on a minor point here. Backpacking is not about saving weight. It's about saving unnecessary weight. Even in the 70s, there were two rules about backpacking weight:

1. If you need it, take it.
2. Minimize the weight of the stuff you need so far as function and budget allow.

Taking a 40-degree bag to save 6 ounces when the forecast is for 20 degree temperatures, and hoping that sleeping in your clothes will make up the difference, is not a valid go-light strategy (in my opinion. I think this may be getting toward what Andrew Skurka calls "stupid light.")

Replacing the stainless steel 2-pot-and-lid cookset with a titanium mug, and using freezer-bag cooking to replace the bowl, makes sense.

Leaving stuff out of your FAK simply because it's heavy isn't smart. Leaving it out because it's not needed based on risk assessment on that trip, or replacing it with something lighter, are reasonable. Eliminating the suture kit is an example of the first; replacing the 300-count aspirin bottle with 10 aspirin in a zip-loc bag is an example of the latter.