Lying in a hospital bed, my seriously obese patient can barely see her swollen and odorous right foot over her abdominal fat. The foot is soon to be amputated, the result of an untreatable infection exacerbated by diabetes and kidney failure, which developed in part because of obesity.

Her two children, ages 6 and 12, hover from the hospital bed to the couch. In between, the bedside table is strewed with empty fast-food bags, pastry crumbs and large soda cups.

Like their mother, the children are exceedingly overweight. The mother is in her 30s; I have all but given up hope for her long-term survival. And as I watch her children, I fear for their health.

Childhood obesity is a recent disease. During medical school in the late 1980s, I do not recall a single lecture or patient case presentation on the subject. But much has changed; in just the past two decades, obesity among children has more than doubled, from 7 percent to 18 percent, and among adolescents it has more than tripled, from 5 percent to 18 percent. These children are more likely to have pre-diabetes, bone and joint problems, sleep apnea, and risk factors for cardiovascular disease.

Certainly parents have responsibility here. But I often wonder: What is the responsibility of the medical establishment?

Last year, the American Medical Association recognized obesity as a disease. We doctors are now struggling to figure out our role in treating this newly declared illness — and how to approach children and their parents about healthy eating and exercise habits that will last a lifetime.

When I spoke about this with a pediatrician in our community, she sounded discouraged. In a typical case of an overweight teenager, she said, “I show the mother the growth curve and point out that the child is way off the charts. Then I ask, ‘Have you thought about controlling the weight?’

“First there is denial,” she said. “And often there is the blame game — it’s the grandma or the dad” who overindulges the child. This isn’t a problem that is easily solved in a doctor’s office, she said.

One tool in her limited kit is something called “5210 Every Day.” Adapted from a program that originated in Maine and is spreading nationwide, 5210 promotes four “numbers to live by”: Kids should eat 5 or more servings of fruit and vegetables a day; spend 2 hours or less on recreational screen time; get 1 hour or more of physical activity; and consume 0 sugary drinks.

She explains the program to her patients and sends them home with a 5210 brochure. A brochure? “How much can I do in 15 minutes?” the pediatrician said. That’s how long she has to tend to the problem that prompted the visit, plus provide other counseling: vaccinations, drinking, drugs, sexually transmitted diseases, bicycle helmets, and yes, diet and exercise. And it may be another year before she sees the youngster again.

I understand the pediatrician’s quandary. For one thing, how do you tell a mother to send her children outside to play if their street has boarded-up windows and drug dealers on the corner? How hard is it for her to buy and prepare fresh foods? In other situations, where families are fortunate enough to live in a safe neighborhood and have plenty of fruit and vegetables in the refrigerator, we see some parents who are too worried about their children’s self-esteem to talk to them about their weight.

These are some ironies of our society and health system: We allow our children to be poisoned by excessive high-sugar, high-fat foods and then we treat them for the diseases that are caused in part by such foods. We spare no expense to save a baby’s life, yet we’re not willing to reimburse doctors for nutritional and social counseling if that baby grows into an obese child.

The U.S. health care system is designed to function best when doctors are treating acute illnesses, such as a heart attack or pneumonia. Slowly it is being pushed to provide better treatment for chronic illnesses such as diabetes. But it still misses the mark on prioritizing and promoting preventive and lifestyle changes.

For a moment I imagine a health care system in which reimbursement is not based entirely on the sickness of the patient but is partly based on what experts call “population health.” Doctors, hospitals, insurance companies, pharmaceutical firms and home health agencies would be paid not only for treating individuals’ illnesses but for demonstrating that they had advanced and maintained the health and wellness of the community.

It would be a gigantic shift. Still, I am hopeful: Much is happening to turn the tide. First lady Michelle Obama is leading the “Let’s Move” campaign, which is placing awareness of childhood obesity on the public agenda. Former New York Mayor Michael R. Bloomberg is trying to limit the size of sugary drinks. And the 5210 campaign and similar programs are spreading to more and more cities.

In Memphis, a community campaign supported by Healthy Memphis Common Table — a regional health collaborative that I helped found a decade ago — appears to have had some encouraging results. The campaign works with local farmers markets, schools and beverage companies; one of its efforts led to junk food being banned from the vending machines in elementary schools, and another turns vacant lots into thriving gardens.

The preliminary results of a study by Vanderbilt University School of Medicine indicate that the rate of obesity among adults here has dropped below the state average, whereas more than a decade ago the rate was 5 percent above the state average. We doctors must look upstream to the causes of obesity and get creative about our role.

As I stood in my patient’s room, where the odor of rotting flesh mixed with the aroma of leftover French fries, I considered her life-threatening infection, preceded by kidney failure and diabetes, which were preceded in turn by a massive weight gain that did not have to happen. I realized she would not live as long as her mother had, and I recalled studies that have predicted that for the first time in U.S. history, children have a shorter life expectancy than their parents, largely because of obesity-related conditions.

The woman I cared for in that hospital died a year later from complications of diabetes, renal failure, hypertension and obesity. It’s her children who need help now.

Manoj Jain is an infectious disease physician and contributor to the Washington Post and The Commercial Appeal.  He can be reached at his self-titled site, Dr. Manoj Jain. This article originally appeared in The Commercial Appeal.