Abstract
This study was conducted to clarify whether preferential fish intake by young adult rats could be linked to fat-feeding during the growth period using a high-fat lard diet (lard HFD) and a high-fat fish oil diet (fish oil HFD) with cellulose added to maintain the same energy concentration as a low-fat diet (LFD). Three groups of 4-week-old male Fischer 344 rats were fed either LFD (LFD group), lard HFD (lard HFD group) or fish oil HFD (fish oil HFD group). After 8 weeks, the LFD, lard HFD and fish oil HFD groups were further divided into 3, 2 and 2 subgroups, respectively, and each subgroup was sacrificed. Blood and liver samples were taken for analysis of lipids. One of the LFD groups and lard HFD groups were placed on a self-selection regimen of LFD and lard HFD, and the other LFD group and fish oil HFD group were placed on a self-selection regimen of LFD and fish oil HFD for 3 weeks. No significant difference in calorie intake or body weight was observed among the groups throughout the experimental period. The ratio of fish oil HFD intake/total dietary intake for rats fed LFD and fish oil HFD was lower than that of lard HFD intake for rats fed LFD and lard HFD. These findings indicate that when rats are placed on a self-selection regimen of LFD and HFD, fish oil HFD has fewer food properties that are preferable to lard HFD.
