A milk substitute is a product that looks and tastes like milk. The mammary glands of mammals produce milk. In milk substitutes many of the ingredients of milk are replaced: A milk substitute may contain fat and proteins obtained from plants. People with a lactose intolerance or a milk allergy often replace milk by a substitute.
The two most common categories of milk substitutes are grain milk and plant milk. The most common grain milk is oat milk, while the most common plant milk is soy milk. Other examples include coconut milk, almond milk, and peanut milk.