Muscle function and nutrition.

Wasting of muscle and a negative nitrogen balance are obvious effects of malnutrition and have led to the use of anthropometric measurements and nitro-gen balance for assessing the extent of malnutrition. A positive nitrogen balance and an increase in limb muscle circumference are believed to be indices of the beneficial effects of nutritional support. In experiments with growing rats and young children nitrogen retention and growth are recognised to be the desirable effects of optimal nutritional intake. This concept has been applied to malnourished adult humans (non-growing) who have been considered to be potentially able to regrow the lost tissue. While it is true that patients receiving long term (more than six months) home total parenteral