There is some speculation that milk is not needed in the diet after weaning, as nutrients become available from other foods. This speculation is partly supported by the fact that after weaning, some people have a reduced ability to digest lactose, the carbohydrate component of milk. However, milk is recognised as a nutritious food and many populations have actually genetically evolved so that they continue to digest lactose and benefit from milk’s nutrients throughout life. This genetic trait, known as lactase persistence, is recognised as an ‘evolutionary advantage’ that arose in populations that farmed dairy animals. The consumption of milk provided an advantage in nutritional acquisition as dairy foods provide a wide range of vitamins and minerals.