To determine if differences in food and water intake, NA (nasal-anal) length, empty carcass weight (ECW), and total fat (TF) were due to the size of the animal, we re-analyzed the phenotypic data to include sacrifice weight (SACW) as a covariate (Model 2, see Materials and Methods). These results indicate that if Lwt/+ mice weighed the same as +/+ mice they would consume significantly more food on a gram per kilogram basis. This analysis also showed that the carcass of Lwt/+ mice is heavier and reduced in total fat. Thus, Lwt/+ mice have a larger proportion of body weight as lean mass and a smaller proportion as body fat (Table 1).
