Background/Objectives: The “One Health” approach underscores the connection between human, animal, and environmental health, promoting solutions to global challenges like climate change and biodiversity loss. The Planetary Health Diet (PHD) promotes a plant-based diet with organically grown plants to reduce the environmental impact of meat production and decrease the risk of non-communicable diseases (NCDs). The BIOQUALIM project will evaluate the PHD’s effectiveness in preventing NCDs like periodontal diseases and cancers through four inter-related studies. Methods: The clinical study will involve volunteers reducing their meat consumption and incorporating einkorn into their diet, allow for analysis of their interdental microbiota, oral health, general health, and quality of life. The chemical analysis will study nutrients and anti-cancer compounds in einkorn and common wheat varieties. The behavioral study will explore PHD knowledge, attitudes, and behaviors related to PHD. The psycho-social study will evaluate the impact of peer-support workshops on plant-based dietary cooking among post-therapy cancer patients. Results: The results are expected to demonstrate that einkorn varieties possess nutritional properties that, when incorporated into the PHD enriched with einkorn, can enhance health markers. This study will identify barriers to and facilitators of PHD adoption and highlight how peer-support workshops can improve dietary adherence. Conclusions: BIOQUALIM’s transdisciplinary approach will demonstrate the PHD’s role in preventing NCDs.