Because the dietitian certificate is a professional grade certificate, you can take it if you want to be a dietitian, but you don't have to take it if you don't want to. It's completely voluntary. Western pastry chef is a pastry baking major, which belongs to the chef industry and requires high professional skills. However, in order to obtain the certificate of nutritionist, we must learn and master the contents and skills of selecting dishes, preparing recipes, basic cooking, nutrition and so on.