Effects of ileal transposition on food intake, dietary preference, and weight gain in Zucker obese rats.

This study evaluated the effects of ileal transposition (IT) surgery on food intake, body weight, and dietary preferences in Zucker obese rats. Eight rats had a 10-cm segment of terminal ileum transposed to the upper jejunum. Eight rats underwent sham IT (SIT) and six rats had no surgery (CON). During weeks 1-10 and 21-24, rats were fed a selection diet of protein (casein), carbohydrate (corn starch), and fat (lard) in three separate dishes. Rat chow was fed from weeks 11 to 20. IT rats had a lower weight and a lower change in weight from base line throughout most of the study. Energy intake was less in IT vs. SIT rats during the selection periods (weeks 1-10 and 21-24), but did not differ on the chow diet (weeks 11-20). Digestible energy, measured at weeks 10, 20, and 24, was lower in IT rats only at week 10. IT rats had no malabsorption by fecal calorie measurements. IT rats ate fewer fat calories at both selection periods. We conclude that IT causes long-term reduction in body weight, no malabsorption or long-term changes in digestible energy, and a persistent decrease in preference for dietary fat. Further studies are needed to determine whether increased energy expenditure is a mechanism for the long-term difference in body weight after IT.