How Nutritional status affects the BMR?

Under nutrition and starvation are the factors which require consideration. Prolonged under nutrition or starvation causes a reduction of about 10-20% in BMR. In semi-starvation studies, data suggest that the subjects BMR decrease by about 25% when expressed per kilogram of their face fat mass (FFM) (or metabolic active tissue). Reduction in BMR are partly mediated through weight loss itself, in which metabolically demanding tissue of the body (the FFM i.e. the lean body tissue) are reduced in size, and partly through reduction in the metabolic activity of these tissues.