The debate over the healthiest diet in the world has never been more active — with Mediterranean, Japanese, vegan, and carnivore diets all claiming to be the optimal way to eat. The Mediterranean diet consistently tops scientific rankings for longevity and cardiovascular health, built around olive oil, fish, vegetables, legumes, and moderate red wine. The Japanese diet — particularly the traditional Okinawan diet — is associated with the longest healthy lifespan in the world. The plant-based diet has strong evidence for reducing cancer risk and environmental impact. The carnivore diet, though controversial, has passionate advocates who report dramatic health improvements. Every diet has its evidence and its zealots. What does the world vote as the healthiest?