PURPOSE OF REVIEW: Protecting the planet is protecting the future. Food production systems are among the most important human activities threatening planetary health. Diet, food systems, the environment, and health are interconnected. Accordingly, this review aims to assess the effects of nutrition on the planet and the relationship between some types of diets defined as sustainable and the planet and human health. RECENT FINDINGS: Many diets have been proposed to protect the planet and human health, but there is no consensus on which diet is best. It should not be forgotten that planetary health diets, plant-based diets, and vegetarian/vegan diets can reduce environmental pressure. Still, they cannot have the same effect in every country, and these diets may have different effects depending on the differences in the countries' income level, nutritional culture, and food systems. Moreover, it should not be overlooked that these diets may cause difficulties in terms of adaptation, cause deficiencies in some nutrients, and may not be suitable for all segments of society. Sustainable diets such as the Mediterranean and New Nordic, as well as Dietary Approaches to Stop Hypertension, are more flexible and acceptable. Instead of a globally recommended reference diet to protect the planet and human health, each country can analyze its food systems and choose the most appropriate food production methods and sustainable diet style to reduce environmental burden, improve health, and create policies accordingly, which can help achieve sustainable goals faster.