The outstanding adaptability of human skeletal muscle through training is evident to everyone who performs even the slightest form of physical activity. No other body tissue shows such a degree of plasticity, and this tissue mass and function is maintained, day and night, day after day, throughout healthy life. Nevertheless, immediately following onset of disease rapid changes occur, and it becomes visible and evident that muscle tissue is wasting. I gained my first, very undesired experience, and a subsequent interest in muscle physiology and muscle mass regulation, as a teenager. At that time I was an eager horseback rider, competing in 3-d events and cross-country. One afternoon my beloved horse named “Blue and White” was severely hurt in her front leg during an exercise on a muddy surface. The accident left her resting in her stable for almost 6 mo and made me a more intense caregiver than ever before in maintaining her mental condition and joy, while seeing the fabulous musculature virtually disappear in this well-trained thoroughbred. As all of us know, the muscle pool is costly to acquire, but it is also certainly costly to maintain. Blue and White happily recovered, and we had many funny experiences thereafter, until she died in 1991 at the age of 21 y. The experience, however, left me with fear and sorrow; how could such a beautiful mass of muscle, attained by so much hard work, just slip away and leave us trying in vane to reconstitute it? Certainly, entering medical school made me realize Blue and White and myself were not unique, but that this was a daily experience in clinical settings. Later on, during my residency in general surgery, it became obvious that, despite technically wonderful surgery, outcome was not only related to the technical procedure. Weaning of respirators, and even coping with activities of daily life, were certainly hampered irrespective of the surgical success per se, and often seemed correlated to the lean body mass, or rather the disappearance of lean body mass. How come? I went to see the Dean of the Medical Faculty, Professor Tore Schersten, to find an answer. It turned out I was not the only one who asked that question. I was subsequently sent to the Surgical Metabolic Laboratory, where this question had been asked for the last 2 decades, and to Dr. Kent Lundholm (later professor). The strategy was, however, not to provide me with an answer; rather here were several outstanding issues that needed an answer or at least an effort, and I found myself recruited as a graduate student! So. .. Because daily normal meal feeding maintains body function and body weight over time, there is no doubt that nutrients are important, although maybe not the only important factor, to maintain body composition. Even minor alterations in nutritional intake will subsequently lead to major alterations in body composition proportional to the time of under-nutrition. Malnutrition and poor preoperative nutritional status severely hamper the outcome of treatment in several diseases. Preservation and restoration of nutritional status due to hospitalization is hence important for recovery in acute as well as in chronic disease, and artificial nutrition has therefore been considered a life-supporting therapy in a variety of patients. Nevertheless, a vast majority of patients receiving hypercaloric feeding by the enteral or parenteral route have been shown to be in positive whole-body nitrogen and energy balance, while still in negative amino acid balance across the leg. 1 Hence, a discrepancy between energy and protein balance in peripheral muscle tissue as compared to whole body is indicated. Consequently, intravenous nutrition might preserve whole-body proteins in metabolically stressed patients, probably by attenuating protein degradation, while failing to increase protein reserves in skeletal muscle. Hereby weight-losing patients fail to catch up in lean body mass. It could be assumed that the integrated anabolic response after ingestion of a meal may be rather complex. This hypothesis was approached in our, now awarded, article “The role of diet components, gastrointestinal factors, and muscle innervation on activation of protein synthesis in skeletal muscle following oral refeeding”; the effect of oral feeding on synthesis of soluble and contractile proteins in skeletal muscle was evaluated, as was the extent to which diet components (carbohydrate, fat, amino acids) and hormones were related to activation of protein synthesis at a translational level. The study confirmed that myofibrillar proteins represent a rapidly extensible pool of amino acids highly sensitive