What Parents Can Do
You have had your toddler drink whole milk up to this point, mainly for the extra fat. Extra fat is important under the age of two for brain development, body growth, and the absorption of fat-soluble vitamins (especially A and D).
That is why it is best to serve whole milk, whole milk yogurt (Yo Baby, for example), and whole milk cheese until a baby's second birthday. I advise parents that it is OK to flavor milk with small amounts of syrup or Ovaltine if they are struggling to get the minimum requirements of milk into their sippy cup-toting child. (Read more about maintaining nutrition for picky eaters.)