A literature review paper looking at complementary approaches to improve the efficacy of standard anticancer therapies – specifically the Ketogenic Diet (KD), characterised as a high-fat (90%), low-carbohydrate (2%) diet with adequate amounts of protein (8%). The KD is a low- cost adjuvant to cancer therapy and is considered promising due to its potential to target metabolic alterations in tumour cells. Research shows it potentially limits tumour growth, whilst protecting healthy cells from damage by chemotherapy or radiation and reducing inflammation. The ketones produced by the high ratio of fat in the diet are used to create ATP energy, which cancerous cells are unable to use. Preclinical studies show that in most cases the KD slowed tumour growth, prolonged survival rate, and delayed the initiation of tumours although this may be influenced by cancer type and genetic background. This implies it’s important to evaluate KD efficiency against each individual cancer rather than as a collective anticancer therapy. Gold standard therapy for some cancers is surgery, radiation, and chemotherapy. However aggressive cancer types with poor prognosis need new approaches where standard therapy is less successful. The authors recognise there is insufficient RCT evidence with large patient cohorts but smaller studies are emerging showing positive results for a KD with patients exceeding their expected lifespan, with reduced tumour growth and progression, reduced glucose up-take at the tumour site and overall improved quality of life. KD seemingly creates an environment in which cancer cells cannot thrive making it a promising adjuvant as a patient-specific multifactorial therapy.