In a July 13 opinion piece in the Journal of the American Medical Association, a pediatrician and a lawyer from Harvard suggest that child-protective services take severely overweight children away from negligent parents. I do think this question should be part of the public debate on childhood obesity.

However, obesity is only one of the many childhood miseries that may be attributable to parental behavior. Restricting ourselves to only medical problems, consider the asthmatic child whose parents smoke cigarettes in the home; the child with food allergies whose parents don't manage to provide an allergen-free diet; the family that chooses to keep a dog in the house after the dog has bitten a child; parents who don't give required medications; parents who don't comply with their own mental health therapies and expose children to excessive stress and emotional trauma; and parents who expose children to domestic violence because they cannot control their own behavior.

The list is long and sad.

Early childhood obesity is a hot topic and a serious problem for affected children, but the law has given states the right to intervene to protect children from harm for a long time. The Child Abuse Prevention and Treatment Act defines abuse and neglect as: "at a minimum, any recent act or failure to act on the part of a parent or caretaker, which results in death, serious physical or emotional harm, sexual abuse or exploitation, or an act or failure to act which presents an imminent risk of serious harm."

State interpretations of this definition vary and are subject to frequent reinterpretations and inconsistent application.

Morbid obesity in early childhood likely meets the "serious physical harm" criterion. The outcomes of obesity include hypertension, sleep apnea, diabetes and plenty of emotional baggage, among other problems. The "imminent risk" issue is harder to prove but not necessary for the definition of neglect.

Some states have already expanded their definitions of medical neglect to include morbid obesity. This expansion makes sense when obesity is predominantly a disorder related to habits — eating and exercise habits — when those habits are avoidable, and when avoiding those habits is likely to make significant difference in the child's well-being.

Generally, aggressive state intervention, such as removing a child from the home, is justifiable only when the state has made all reasonable efforts to help the family change its ways and protect the child. But what constitutes reasonable efforts with childhood obesity? Education? Prescribed diets? Ensuring access to healthier food by insisting that grocery stores offer cheap fresh food? Income supports? Visiting nurses who teach cooking? YMCA membership? Safe neighborhoods for outdoor play?

Another criterion for aggressive state intervention should be that the intervention is less horrible than the child's current situation. Being separated from the family is very hard on most children. Our foster care system has had its share of problems. While it is easy to be angry at inadequate parenting, the level of inadequacy that causes more harm to the child than being taken away is sometimes hard to identify.

We should always be cautious when we try to consider the well-being of a child independently from the well-being of the family. And we have a long way to go toward improving the nutritional environment in this country, especially for poor families in urban settings.

It makes sense that states should have the option to remove a child from an unsafe environment. When that environment is the family, the move should be based on rigorous evidence and taken with utmost caution, sympathy and humility.

Dr. Margaret Moon is a pediatrician at Johns Hopkins Hospital and a core faculty member of the Johns Hopkins Berman Institute of Bioethics. Her email is mmoon4@jhmi.edu.