Table 4.

Weights of tissues of 13-week-old rats (Charles River Laboratories) fed a low-fat or high-fat diet between 4 and 13 weeks of age¹,²

Variable	Low-fat group	High-fat group
Body weight, g	476 ± 12	518 ± 14†
Tissue weight, g
•Heart	1.74 ± 0.06	1.96 ± 0.05*
•Lungs	1.81 ± 0.07	2.07 ± 0.08*
•Liver	12.6 ± 0.37	13.9 ± 0.35*
•Spleen	0.83 ± 0.02	0.85 ± 0.03
•Kidneys	2.76 ± 0.05	2.94 ± 0.06*
•Retroperitoneal adipose tissue	8.66 ± 0.32	11.4 ± 0.39†
•Epididymal adipose tissue	8.57 ± 0.36	10.9 ± 0.41†
•Inguinal adipose tissue	7.92 ± 0.28	10.6 ± 0.35†
•Mesenteric adipose tissue	4.01 ± 0.13	5.30 ± 0.28†
•Major white-fat3	29.3 ± 1.8	38.4 ± 2.4†
•Brown adipose tissue	0.68 ± 0.03	0.67 ± 0.03
•Small intestine	6.16 ± 0.20	6.88 ± 0.23*
•Pancreas	0.94 ± 0.03	0.95 ± 0.04
•Soleus muscle	0.208 ± 0.005	0.232 ± 0.006†
•EDL muscle	0.214 ± 0.006	0.239 ± 0.008*
•Testes	3.75 ± 0.04	3.78 ± 0.05
•Brain	1.72 ± 0.05	1.76 ± 0.06
Fat and non-fat mass4, %
•Fat mass	15.3 ± 0.8	18.4 ± 1.1*
•Non-fat mass	84.7 ± 0.8	81.6 ± 1.1*

¹See Table 2 for experimental detail.

²Values (expressed as gram) are means ± SEM, n = 8 rats/diet group. Rats were fed a low-fat or high-fat diet between 4 and 13 weeks of age, and euthanized at 13 weeks of age to obtain tissues. Individual animals were homogenized to determine fat and non-fat mass (33).

³The sum of epididymal, mesenteric, retroperitoneal and inguinal (subcutaneous) adipose tissues.

⁴In rats fed the high-fat diet, fat content in the body increases by 20.3% while the non-fat content decreases by 3.7%, when compared with the low-fat group. Overall, at 13 weeks of age, total amounts of fat per rat are 73 and 95 g, respectively, in the low-fat and high-fat groups, whereas total amounts of non-fat mass (lean tissues) per rat are 403 and 423 g, respectively, in the low-fat and high-fat groups.

^*P < 0.05 and

^†P < 0.01 vs the normal-weight group, as analyzed by the unpaired t-test. EDL, extensor digitorum longus.