Amaranthus spp. is a highly nutritive pseudocereal, rich in macronutrients and micronutrients, including vitamins and minerals. Amaranth grain is rich in essential amino acids, particularly lysine, with high nutritional quality. In addition, recent research studies demonstrate that Amaranthus spp. essential nutrients, such as phytochemicals, have potential beneficial health effects. This review focuses on the amaranth grain's nutritional composition and antioxidant capacity. Also, limitations on its intake and strategies to improve its digestibility, bioaccessibility and bioavailability are summarized in this review. Finally, the most recent literature studies reporting food applications of amaranth (e.g., as encapsulating material) are discussed in order to deepen the understanding of potential health benefits and functionalities of this nutritious grain.