Since global demand for aquaculture products is expected to increase dramatically in the near future, policymakers and companies are considering the adoption of insect-based feed, which is more economically viable and environmentally sustainable than fish or vegetable-based meals currently used. Nonetheless, fish farmed with insects are still perceived as innovative products by consumers, and further studies exploring these demand-side concerns must be conducted to make sure a market for such products exists. This study focuses on the factors that can favour the acceptance of farmed fish fed with insects of a sample of young Italians. In particular, within the theoretical framework adopted in this analysis, we let acceptance be expressed by different dimensions, each potentially influenced by individual factors, such as socio-economic characteristics, as the provision of information on the nutritional and environmental benefits of insect-based feed for aquaculture, and as consumer psychometric indicators. In this respect, we use the by-dimensional definition of environmental attitude proposed by environmental psychologists, that considers attitude toward environmental protection and toward nature. In this survey, we reached 482 consumers, aged less than 40, using social networks. A Factor Analysis was performed to identify the different dimensions of the acceptance process. We then applied the Rasch model on consumers’ reported behaviours toward environmental protection or nature to retrieve their environmental attitudes. We performed a Seemingly Unrelated Regression to assess the importance of socio-demographic, information, and psychometric variables on the different dimensions of acceptance. Results indicate that the use of psychometric variables to study the acceptability of an innovative food product seems particularly appropriate. In addition to the role of environmental attitude, acceptance is also explained by some socio-demographic variables, with men and younger consumers being more inclined to accept the product. Acceptance is also higher among informed respondents, confirming the importance of reducing information asymmetries.