If only it were that simple.

Observations about childhood obesity offered this week by Dileep Bal, the cancer expert who now is Kaua'i health director and adviser to the state's health department, are painfully correct.

Hawai'i's kids do eat too much junk food and exercise too little. And the best hope for turning the tide in the national battle with weight control lives in our children.

But in a world flooded with contrary media messages, schools surely aren't the root problem.

Speaking to an assembly of teachers, Bal advised educators to help stem the obesity epidemic by urging students, through curriculum and other means, to eat better and become more active.

To some extent, the schools have made improvements, reducing the amount of sugary soft drinks sold on campus. Certainly, that issue merits revisiting: Kids' food choices, along with the message they convey about nutrition, should be evaluated repeatedly.

And despite the pressures to fulfill competing curricular demands, schools must persist in strengthening lessons on nutrition and fitness and yield none of the time spent in physical education.

But it's wrong to let the duty rest on educators, who are carrying a full load already. Teachers are fighting a losing battle if not joined by a equal or greater drive at home and in society as a whole.