T Nation

FFMI (Fat Free Mass Index)

Hey CT,

Just wondering if you’ve heard of the ffmi and what your thoughts were.

  1. Particularly I’ve heard that it can be used to vet whether someone is a suspected steroid user.

  2. I’ve heard that the general upper limit of a non user (when very lean) is about 25. They cite previous bodybuilders from the pre steroid area who supposedly possessed this ffmi.

  3. Wondering what the implications of this could be if one were approaching the upper limit of the ffmi index and if the person could modify their training (ie. if all I can expect is to max out at about 25 why not train less hard and “maintain”)

It should be noted that again ffmi is stated to only be relevant to lean individuals. For example I am 207lbs 6’0" with about 12-14%BF and my FFMI was supposedly about 25. The issue is that as one gains total weight they will obviously gain fat free weight as well which skews the results.


Thus I would be “approaching the natural limit of ffmi” but this is actually not the case because if I dieted down to 6-8% body fat I would obviously lose some muscle.

If you have any opinion or knowledge on the subject could you please address my three numbered points?