Feed your FFM (and then some), or it'll FEED ITSELF! (hint - that's bad!).
As the name suggests, FFM is the collection of tissues in our body that is not fat. It consists of our internal organs, the muscles and connective tissue such as tendons and ligaments, the skeleton, skin, blood, lymphatic fluids, nerves, etc. I often describe FFM as the metabolically active part of your body that needs to be fed, as opposed to the fat mass (which amongst it's several important functions, is stored energy that is there to feed us when intake is low).
Understanding that FFM needs to be fed is a great way to begin explaining your Basal Metabolic Rate (BMR) and it's significance. People very often assume that your BMR is the number of calories you need to eat if you're trying to 'maintain' your weight; so naturally if you want to loose weight you will need to have a deficit - so they eat less than this number - WRONG!
