Gastrointestinal and cardiac response to refeeding after low-calorie semistarvation

A recent development in the treatment of obesity is the widespread use of very-low-calorie diets. This study assessed the response to refeeding (RF) after semistarvation (SS) in a rat model. Male Sprague-Dawley rats (440 g) were semistarved for 21 d, receiving a nutritionally complete defined formula diet at 23% of calories of control (C) rats fed ad libitum, and subsequently refed over 21 d (SS----RF). Organ weight, contents of protein and DNA, and the protein-DNA ratio were determined for the liver, pancreas, small intestine, and heart. Compared with C animals, SS----RF animals showed variable repletion of tissue protein but not of tissue DNA. The higher protein-DNA ratio shown in these organ systems suggests a cellular hypertrophic adaptive response to refeeding. A persistent reduced number of cells in ratio to protein concentration is evident despite refeeding over 21 d. Very-low-calorie diets as well as refeeding influence nitrogen economy of selected organ systems.