Effect of Lard, Soybean Oil and Fish Oil High-Fat Diet during Growth Period on Preferential Fat Intake in Adult Rats

We examined the effect of fat and oil intake during growth period on preferential fat intake in adult rats using high-fat diet (HFD) with cellulose added to maintain the same metabolizable energy concentration as low-fat diet (LFD). Four groups of 4 week-old male Fischer 344 rats were fed either LFD (LFD group) or one of three kinds of HFD with cellulose added (lard HFD, soybean oil HFD and fish oil HFD group). After 8 weeks, three HFD groups were placed on a self-selection regimen of LFD and each HFD for 3 weeks to examine the ratio of HFD and LFD intake. No significant difference in calorie intake and body weight was observed among all groups through the experimental period. However, during self-selection period, ratio of HFD intake (HFD intake (g)/total intake (g)J for fish oil HFD group was lower than that of lard and soybean oil HFD group. Within first week after self-selection regimen, the ratio for lard HFD, soybean oil HFD and fish oil HFD group was 50%, 30% and 17%, respectively. However, the ratio for lard and soybean oil HFD group decreased and reached about 20% within third week after self-selection regimen. The amount of fat intake was calculated 6g/100g diet. These findings indicated that (1) lard HFD has food properties preferable to soybean oil HFD and fish oil HFD, (2) HFD with cellulose added to maintain the same metabolizable energy concentration as LFD guards against overfeeding of fats.