However, even when the costs of weight assessments and counseling are fully covered by insurance, it seems they are rarely done. In November 2011, the Obama administration offered free weight-loss counseling to obese seniors on Medicare, with no co-payment or deductible for those with Medicare Part B insurance. The benefit, which is still available, applied to the approximately 30 percent of Medicare beneficiaries with a B.M.I. of 30 or more.

Yet in the first three years, only about 120,000 seniors, representing less than 1 percent of those on Medicare, took advantage of this benefit, a result weight-loss specialists have called “very disappointing” and “a huge lost opportunity.”

The free coverage includes weekly counseling for the first month, a session every other week for months two through six, then monthly sessions for another six months for those who lose at least 6.6 pounds by the sixth month. Participants who fail to hit the six-month target can get a second chance six months later, with no limit to how many times they can take advantage of this benefit if their B.M.I. is still 30 or higher.

To be sure, many of those with serious weight problems have probably tried and failed to lose weight and keep it off, leading them to think there’s little hope that yet another effort will bring success. But it is worth noting that for most people who managed to quit smoking, it typically took anywhere from eight to 30 attempts.

The fault with weight-loss failures may lie almost as much with health care practitioners as with their patients. Many primary care doctors have little to no training in how to counsel patients who need to lose weight. Some have told me that they are afraid patients won’t come back if they focus on a need to lose weight. And patients are often turned off by what they perceive to be their health care providers’ negative attitudes toward people with weight problems.

An online survey by researchers at Yale University’s Rudd Center for Food Policy and Obesity revealed that people considered terms like “obese,” “fat” and “morbidly obese” to be stigmatizing and blaming language used by doctors. Nearly one participant in five said they would avoid future medical appointments, and 21 percent said they would seek a new doctor, if they felt stigmatized about their weight.

The Medicare opportunity notwithstanding, there is a growing need to tackle weight issues much earlier in life. Researchers at the Harvard School of Public Health reported in JAMA in July that 23 percent of women and 13 percent of men gained 44 pounds or more between the ages of 18 and 55. And Dr. William H. Dietz of the C.D.C., who noted in an accompanying editorial that “obesity-related cancers in both men and women were associated with moderate weight gain during adulthood,” added that “efforts to prevent and control obesity in young adults should be accorded a high priority.”