Exposure to mouse dams to bonito broth during gestation or lactation reduces fat intake in offspring

Overconsumption of fat contributes to obesity and low adherence to dietary therapy in patients with obesity. The frequency of consuming soup dishes containing "dashi" (Japanese broth), a characteristic element of the Japanese diet, is negatively associated with obesity indicators. The use of dashi is considered one of the reasons why the low-fat Japanese diet is popular; however, whether and how dashi controls the selection and intake of fat is unknown. In this study, we tested the hypothesis that bonito broth, a typical Japanese dashi, affects fat consumption in a mouse model. First, we examined the long-term or short-term intake of corn oil emulsion in adult mice fed bonito broth. No significant effect was observed. Next, mouse dams were fed bonito broth during gestation or lactation and licking of 0.5, 1, 2.5, 5, and 10% corn oil in their adult pups was evaluated in acute tests. Compared to the control group, there were significant decreases in licks for some corn oil concentrations in the gestation and lactation groups. Finally, corn oil licking was tested in pups fed bonito broth after weaning. No significant effect was detected. This study suggests that dams' intake of bonito broth during gestation or lactation reduces the intake of fat by their pups in adulthood.