Fat tissue transplantation is a useful and common clinical technique in the plastic and reconstructive surgeries. To know the nutritional effects on the survival and maintenance of fat grafts, the weights of tissues and cell sizes, and the gene expressions in the fat tissues were analyzed 14 days after transplantation. The body weight and the plasma insulin level in high nutritional group (HNG) were significantly higher (p < 0.05) than those in low nutritional group (LNG), respectively. The measurements of cell size showed that there were 32.5% distributed in the diameter less than 2 mum in LNG, significantly higher than 28.5% in HNG. There were 7.5%, distributed in the diameter more than 6 mum in LNG, significantly lower than 10.0% in HNG. The mRNA levels of leptin, lipoprotein lipase, and beta(3)-adrenergic receptor were 2.0-, 1.5-, and 1.7-fold higher in HNG than those in LNG, respectively. The levels of hormone sensitive lipase and hexokinase 2 transcripts were not significantly different in both groups. These results show that the systemic nutritional status in host causes the changes of cell size and tissue weight as well as gene expression in the transplanted fat using mice model. The nutritional condition is probably important for the fat graft clinically both as lipid-storage and functional cells. (C) 2002 Elsevier Science (USA). All rights reserved.