It's a good idea to open a slimming restaurant, but any investment is risky, just depending on the size of the risk. In order to reduce the risk of operation, investors need to do a good job in market research in the early stage, understand the base of consumers, as well as the positioning of products and so on.
If you have no experience in catering business, you can go to a professional catering training institution to study. After systematic training, you can also take fewer detours in opening a store.