Milk may do a body good, but when is the best time to start giving milk to your child? And what kind of milk should it be?

Experts say most children are ready to start drinking whole milk at about age 1.

"It's best to start children on whole milk and not 2%, 1%, or skim milk, because their energy needs are very high and they need that fat in the whole milk for energy," says Robert Murray, MD, director of pediatric gastroenterology and nutrition at Columbus Children's Hospital in Ohio.

At about age 3, Murray says most children can make the switch to 2% milk, and by ages 5 to 6 most are ready to go to skim milk.

"They need a little extra fat in the first few years, but by the time children enter school, they have a broader diet with other sources of fat," says Murray, who presented research on child nutrition at the American Academy of Pediatrics National Conference and Exhibition in Boston.

Murray says the only reasons a child should not be given cow's milk are if the child has a milk allergy or the child's pediatrician has another medical reason to withhold milk.

Milk allergies are rare, but some children might eventually develop lactose intolerance, which is an inability to properly break down the sugars in milk and other dairy products. Usually this condition develops later in childhood, once the child reaches school age. People with lactose intolerance can experience gas, abdominal pain, bloating, and diarrhea after ingesting dairy products.

But Murray says there is a wide variation in the level of lactose intolerance a child might have. Some might be able to tolerate a small dose of dairy, but not a lot at one time. For example, a slice of pizza and a milkshake might be too much for the child's digestive system to handle, but having milk on his or her morning cereal may be fine.

If parents suspect their child is having problems digesting milk or other dairy products, they should consult their pediatrician. The doctor might recommend that a child diagnosed with lactose intolerance drink specially processed milk, such as Lactaid, or take tablets to help them break down the sugars in milk.

Murray says that although other types of milk, such as soy milk, are often fortified with calcium, they do not contain the broad range of nutrients that cow's milk does. And for young children who have a limited diet, it might be a struggle for them to get these nutrients from other sources.

He says parents may have also heard wild claims about various elements in some types of cow's milk being hazardous to children. For example, there has been some speculation about human growth hormone, which is used by some milk producers, and a potential link to developmental problems. But Murray says that at the moment, speculation is all it is, and there's no evidence to suggest that cow's milk poses any danger to children.

Published Oct. 28, 2002.