Plant-based diets for human health with implications for cardiometabolic health, gut microbiome, and nutritional adequacy.

Plant-based diets have gained considerable interest in recent times due to their perceived health and environmental benefits. However, the term "plant-based diet" refers to a broad range of diets with a wide range of differences in food quality and nutritional content. This article aims to summarize the available evidence regarding the health and environmental impacts of plant-based diets, including new trends and issues. Epidemiological studies, RCTs, and life cycle assessment studies were searched in various scientific databases to investigate the relationship between plant-based diets and various health outcomes or environmental impacts. Available evidence from prospective studies and RCTs suggests that well-planned plant-based diets are associated with a lower risk of cardiometabolic diseases and beneficial alterations in the gut microbiome. Environmental studies have uniformly found lower greenhouse gas emissions, land use, and water use associated with a human diet compared with an animal-based diet; however, the extent of these positive impacts depends on the diet composition. On the other hand, nutrient adequacy such as iron, vitamin B12, omega-3 fatty acids, processing, and socio-economic factors are also important considerations. This review aims at an integrated approach in environmental sustainability viewpoints with health results, comprehensive understanding the relationship between the quality of diet and health outcomes in the context of a circular food system and research priorities in guiding future diets.