Dietary Intervention Studies: Design, Follow-Up, and Interpretation

Cumulative knowledge on dietary bioactive compounds has shown their potential in the prevention or management of several non-communicable diseases, such as cardiovascular diseases, type 2 diabetes, or certain kinds of cancer. However, a complete validation of their biological effects through clinical trials is still missing in many cases. The present chapter aims to provide a practical guide for the development of nutritional clinical trials, considering the key steps to be carried out: design (considering type of study, inclusion and exclusion criteria of the participants, sample size calculation, or biological sample collection), recruitment process, follow-up, and result interpretation. A particular emphasis on legal aspects specific of this particular research, such as ethics committee, personal data protection, or biological samples management, is provided. Also, some considerations when comparing results from nutrition clinical trials or drug clinical trials will be explored. Overall, it is expected that this chapter will be a helpful resource for researchers interested in validating the effects of food bioactive compounds.