For aquaculture sustainability, broodstock diet for carnivorous species will rapidly evolve toward a decrease of the protein-to-carbohydrate ratio, with the substitution of the protein-rich fishmeal by plant-derived carbohydrates (Callet et al., 2020). Numerous studies have reported that parental high carbohydrate (HC)/ low protein (LP) nutrition could affect their progeny epigenetic landscape and subsequently their metabolism in various species (Gao et al., 2020). In carnivorous fish species, even though the effects of parental nutrition have already been demonstrated (Hou et al., 2020), the consequences of parental HC/LP have never been explored until now. To investigate this question, two-year old male and female trout were fed either a control diet (0% carbohydrate and 63.89% protein) or a diet containing a high proportion of carbohydrates (35% carbohydrate and 42,96% protein) for an entire reproductive cycle for females (10 months) and 5 months for males. Crossed-fertilizations were carried out in order to obtain four groups of fish. Samplings and DNA extractions were performed at different life stages in order to quantify the proportions of the four forms of methylatedmethyl- cytosine (5-mC) derivatives (5-mC, 5-hmC, 5-fC, and 5-caC and 5-C), by HPLC-UV analysis. Before the first feeding, the maternal HC-LP nutrition induced at the same time a decrease of 5-mC proportion decrease and an increase of 5-caC proportion increase in their progeny (whole fry). These effects were enhanced by the paternal nutrition (Callet et al. 2021). The underlying mechanisms probably include the modulation of the expression of the genes coding for the enzymes responsible for the de novo methylation, as transcriptomic analyses revealed that dnmt3bbb relative expression was significantly reduced by the parental nutrition. Such outcome is maintained over time and regardless of the diet given, as the maternal HC-LP nutrition also triggered a decrease of both 5-mC and 5-hmC proportions in the liver, after a 9-month feeding trial. Interestingly, a previous study has also reported a global DNA-hypomethylation in juvenile trout which were directly fed with a high carbohydrate diet (Marandel et al., 2016). Overall, the data accumulation suggests that HC-LP nutrition, whether directly or indirectly via parental nutrition, highly modulates the DNA-methylation landscape in trout.