Many mothers have become accustomed to reaching into their refrigerators, pushing their own containers of low-fat milk aside, and grabbing the whole milk to pour into their toddlers' sippy cups.

But following revised guidelines by the American Academy of Pediatrics, some physicians are now recommending reduced-fat rather than whole milk for children between 12 and 24 months of age.

Doctors hope the change lowers the risk of childhood obesity. And, while some parents bask in the glory of a less-cluttered refrigerator, others fill the void with worry over whether the less-fat milk is the right choice for their children.

The AAP report, titled "Lipid Screening and Cardiovascular Health in Childhood," advises the consumption of 2 percent milk for babies most at risk for obesity, cardiovascular disease and high cholesterol.

Although cardiovascular disease ranks as the leading cause of death among adults — with most symptoms occurring later in life — the report, published in July, cites studies indicating early onset of fat buildup in the arteries.

"The biggest danger, by far, is that an obese child is going to become an obese adult," said Dr. Steven Killough, of Lancaster Pediatric Associates. "But even very early in the game, we're finding those deposits being made in the large blood vessels. In kids who have died for other reasons, who have had autopsies, we've found plaque being formed at a very early age."

Although the report, which replaces a retired 1998 policy on cholesterol in childhood, advocates targeted application of the guidelines and correlated screenings, Killough said the policy proves beneficial for the majority of infants.

"We're really applying it across the board because obesity is such a social factor, as well as a genetic factor, that we can't predict who's going to wind up being aggressive eaters and who's going to wind up being aggressive athletes," said Killough.

In accordance with the new guidelines, Killough recommends breast milk or formula for the first 12 months, followed by 2 percent milk for infants between 12 and 24 months. At age 2, children may taper down to fat-free milk, which Killough also calls ideal for adolescents and adults alike.

The previous recommendation, which called for whole milk for children between 12 and 24 months, followed by 2 percent for 2-to 4-year-olds, rested on the traditional belief that fats aid the healthy and proper development of myelin, a substance that forms a sheath lining the nerve cells in the brain.

"It has always been a question of balancing two competing considerations, both of which, of course, are valid concerns," said Dr. Stephen Gershenson of Kids First-Highpoint in Chalfont, Bucks County. "The prevailing pediatric consensus has always been to emphasize brain and nervous system development early, when it is still developing and then to emphasize cholesterol issues, more than obesity, per se, in older infants. Obesity is a very real emphasis in pediatrics now, but the real concern about dairy fat has always been that it is a major contributor to the atherosclerotic, or lipid, deposits that build up over a lifetime."

Gershenson said that although considerations for reduced-fat milk might be necessary in the case of an already-obese baby, he believes, in most average-weight infants, whole milk "would not condemn a child to a lifetime of obesity or atherosclerosis, as long as the family can be vigilant about controlling fatty foods and overeating through the remainder of childhood."

Joanna Spicer, of Lancaster, chose whole milk for her daughter, Abigail, who is now 3, based on the recommendation of her family doctor. Despite the revision of the guidelines since that time, she plans to do the same for her 12-month-old son, Daniel, as he prepares to transition from breast milk to store-bought dairy.

"Every child is different and I feel strongly that not all children should follow every recommendation that is thrown our way," said Spicer. "My children are extremely different in many ways: gender, personality and body structure. ... I think that doctors should focus more on what is healthy for each individual child and so should parents."

Spicer said as a new mother she felt overwhelmed by the multitude of advice coming her way. Whereas Abigail thrived on formula, Daniel took to breast-feeding more easily.

She said ensuring her children's proper development remains of highest regard. As for the obesity epidemic, she blames lifestyle and genetics, but not necessarily whole milk.

"If a doctor can determine that a child's obesity is caused by genetics, then yes, recommend 2 percent milk," she said. "If the obesity is caused by lifestyle, then come up with a plan to change the bad habits. ... I will encourage my children to exercise through play and I will get my exercise by playing with them."

Dr. Goutham Rao, clinical director of the Weight Management and Wellness Center at the Children's Hospital of Pittsburgh, said frequent physical activity undoubtedly reduces the risk of childhood obesity. It's not the only factor, however.

Through his studies, he has pinpointed the intake of sweet beverages and fast food, as well as prolonged periods of "media time" — time spent sedentary in front of the television, computer or video games — as factors that increase a child's risk of becoming overweight. He notes a subsequent decrease in risk, however, for children who sit down regularly for family dinners, being supervised by at least one parent or guardian during mealtime.

"While I support the AAP recommendations and recognize that whole milk is a cause of excessive weight gain in some children, there are so many other behaviors that contribute to childhood obesity, I'm not sure that switching to low-fat milk will make much of a difference," said Rao. "Essentially, I believe it's difficult to know whether this one change will have much impact, given that so many children are given juices and other sweet drinks and other sources of excess calories."

Killough said, even before the revised guidelines, the pros and cons of whole milk have always been a game of odds. He said although the new rationale might not solve the obesity epidemic, it doesn't hurt to try.

"It's all additive," he said. "We've probably got better control over the kind of milk they're drinking as a 1- to 2-year-old than we do over how many french fries they're going to be eating as a 2- to 3-year-old. But we like to address both those concerns. I think patterns are set very early in life and if you tend to start gaining weight more than you need to in the beginning, you'll have a much better chance of continuing to do it."

Killough said overweight parents must address obesity as a family if they expect their children to reap the benefits. As for those parents fearing the revised guidelines might not provide enough nutrition for their children, he said the body has a unique way of placing chemicals where they are required.

"Parents think their kids are wasting away already and that if we put them on skinny milk that their children just won't grow up strong and tall," he said. "They don't realize that adding the fat just makes them fatter, but no stronger or taller."