Figure 8.
Cluster analysis of body weights for 13-week-old male Sprague-Dawley rats (Charles River Laboratories) fed a low-fat (LF) or high-fat (HF) diet between 4 and 13 weeks of age. See Table 2 for experimental detail. Some rats in the LF group were obese, and some rats in the HF were resistant to the development of obesity. Two clusters of animals are clearly found in the plot based on the initial weight gain during the first week of HF feeding and the body weight at week 13. The rats weighing ≤ 470 and ≥ 470 g at 13 weeks of age are classified as normal-weight (yellow circle) and obese (blue circle), respectively. The mean body-weight in the obese group is 23% greater than that in the normal-weight group (536 vs 436 g).