Numerous food products may be derived from GMO. A risk assessment is required in each case, involving four steps: - an analysis of the genetic construction, - a biochemical, functional and toxicological characterisation of the new expressed proteins, - a determination of the nutritional value of the new food, - an evaluation of unintended effects. Subchronic-tests are preferred to acute toxicity assays. Controlling the degradability of new proteins by digestive simulation tests and mutagenicity tests may be discussed. Lastly it is also recommended to perform tolerance studies by feeding experimental animals with the final new products.