Anyone who has ever tried to lose weight — and who confronts the issue honestly — will have to admit that it is within their power to succeed, but that they are up against some truly terrible headwinds.

Everything from marketing — cheap but calorie-laden servings pitched to families as good value — to the tools and distractions of society that keeps them sedentary, combine to work against them. Even so, the toll paid for obesity, in health risks and a diminished quality of life, is so high that a concerted effort to combat the problem should become a national focus.

Enlisting people to that cause is the ambition of a new report released last week at the Centers for Disease Control and Prevention "Weight of the Nation" conference in Washington, D.C. It’s paired with a four-part HBO documentary premiering tomorrow (see box).

On the staff of experts steering the whole project is M.R.C. Greenwood, the president of the University of Hawaii whose own academic background lies in diabetes and obesity research. She shared some sobering statistics for this state in particular.

For example: In the past 15 years, Hawaii’s rate of obesity more than doubled, from 11 percent in 1995 fo 23 percent in 2010. And, she added, by the time they enter kindergarten, one in three Hawaii children already could be classed as overweight or obese. Similar children’s rates are cited in the "Weight of the Nation" report, in fact, for the nation as a whole, in which two out of three adults are considered to be at least overweight.

The problem areas are less surprising than how much must be overcome. From the report:

» Exercise — Americans have long been sedentary, and it’s getting worse. In 1977 only 20.2 percent were walking to school; now it’s down to 12.5 percent. Overall, only 19 percent of all Americans get the recommended amount of physical activity.

» Food and beverages — In 1971-74, the average adult consumed 1,996 calories. By 2008, that was up to 2,234. A full 20 percent of the rise in average weight since 1977 can be pegged to sugar-sweetened beverages.

» Marketing — Roughly 87 percent of foods and beverages advertised to kids on TV were items high in sugar, fat or sodium.

» Workplace — About 25 percent of a working adult’s life is spent at his or her office.

» Schools — Up to half of a child’s waking hours are spent in school, where the percentage of high school students attending physical education classes has dropped from 41.6 in 1991, to 33.3 in 2009.

That last figure is dispiriting but explainable: Academic testing requirements under the federal No Child Left Behind law have driven many schools, here as well as nationally, to reduce the time alloted for P.E. That must be reversed. Education should be seen as exercise for the body, as well as the mind, to produce a truly healthy adult.

A part of the job in reversing these trends undeniably lies with personal and parental responsibility. Creating good eating habits begins young, and it starts in the home.

But in the wider world, steps also must be taken. Safe places for walking and exercise must be a central element in any community’s design. Better policies on clearer food labeling should be considered — sugar content is high in fruity drinks as well as soda.

Overall, better choices in foods should be made more broadly available. Projects, including one partnering Kaiser Permanente and the nonprofit Kanu Hawaii, seek to bring produce markets to areas such as senior housing and lower-income residential zones that are known as "food deserts," lacking in healthy food options. These should be encouraged.

Public education is also a good starting point down this path. A documentary series that brings the issue home would be worthwhile watching.

Of course, getting up off the sofa afterward, to begin the work of changing those sedentary habits, must be the next step.