Foods with the highest iron density often include organ meats (especially liver) and certain seafood. These provide heme iron, which is absorbed more efficiently than plant-based iron. However, “highest” should be interpreted with portion size and frequency—eating liver daily is usually not necessary. Other strong options include red meat, sardines, and shellfish like mussels. On the plant side, pumpkin seeds, sesame/tahini, lentils, and iron-fortified cereals can contribute significantly, but absorption improves when paired with vitamin C.