Second, if you’ve got it in your head that any intervention we try has to be evidence-based, you may as well go home now. Most of the evidence we have is evidence of failure; the record of attempts to curb obesity is grim. Just about nothing works in the long term. We are, all of us, shooting from the hip.

There are a couple of, if not bright, slightly less dim spots. I’ve seen two community-wide programs that have shown some long-term success, compared with similar communities where no intervention was tried. One was in a town outside Boston (Shape Up Somerville), and one was in France. Both were takes-a-village combinations of school and community programs targeting both kids and parents, food and physical activity, and both showed modestly better results than control communities.

AD

AD

They offer a hint of what every obesity expert I’ve ever spoken with has told me: There’s no one fix, and a multipronged approach is our best hope. It’s a tough spot. Individually, just about no interventions make a dent in obesity, yet we’re speculating that, in combination, they might. Tell that to the food manufacturer who has to change packaging, or the restaurateur who has to post calories. “Well, this thing probably won’t do much, but we’re hoping that if we do enough of these things it’ll help.”

That is the underwhelming reality. We need a multipronged approach even though no individual prong has yet proved to be all that successful.

But which prongs? Six suggestions appeared over and over again.

AD

1. TAXES

For many, it’s a soda tax. For Cornell professor John Cawley, it’s a “broad-based national tax on energy-dense foods.” He emphasizes both that it be national (because “It’s easy to evade” state or local taxes), and that it be on all foods that are “high-calorie and zero-nutrient” because consumers can trade one lousy food for another when the tax is narrow. Out with the Coke, in with the Oreos. Where soda taxes have been implemented (Mexico , Berkeley, Calif.), there’s evidence of reduced purchasing or consumption, but we have no idea what people are eating or drinking instead, or whether there’s any impact on public health.

AD

Some respondents suggested using the tax revenue to subsidize healthful foods, although that kind of effort also hasn’t shown a big effect.

2. REFORMS TO SNAP

The Supplemental Nutrition Assistance Program (formerly known as food stamps) has few limits on what recipients can buy. Cawley would eliminate from the SNAP program the same high-calorie, zero-nutrient foods he’d like to tax. Margo Wootan, nutrition policy director for the Center for Science in the Public Interest (CSPI), would eliminate soda and add incentives for fresh fruits and vegetables — a change with more broad-based support. One Twitter suggestion was to add a meal kit component to SNAP. We can only speculate on what impact these various changes would have.

3. EDUCATION

Start young, by working nutrition into the curriculum. Bring back home ec! Teach kids to cook! And plant gardens at schools. Dariush Mozaffarian, dean of Tufts’ Friedman School of Nutrition Science and Policy, adds education of medical students to the list. There’s an extensive body of research on educational programs; some show promise, but there’s little long-term follow-up.

4. FOOD LABELING

This includes calorie labeling at restaurants and clear (perhaps front-of-package) labeling on food. Evidence on restaurant labeling is equivocal, with some studies showing a small decrease in customers’ calorie counts and others showing no effect. On front-of-package, all evidence I’ve seen is hypothetical, with research subjects reacting to different designs; there’s very little real-world experience.

5. MARKETING

Curb food advertising to kids and maybe even to adults. While some governments (Norway, Sweden, Britain, South Korea) have restricted advertising, and some industries (U.S. beverage industry) have adopted voluntary guidelines, there’s not even strong evidence that kids’ exposure to ads has been substantially reduced, let alone evidence that there’s been a positive public health impact.

6. PHYSICAL ACTIVITY

Make it easier! Suggestions mostly focused on good old PE in schools and sidewalks and green spaces in cities. Evidence on PE is squishy; it may not improve BMI, but nobody thinks exercise is a bad idea.

In the miscellaneous category, several people suggested restructuring farm subsidies, an idea I support even though it won’t have much effect on prices and almost certainly won’t help on the obesity front. Mozaffarian suggests fruit and vegetable prescriptions, targeted at in-need populations, and procurement standards for hospitals.

A couple of innovative ideas came from my Twitter stream: Don’t give sugar to kids who aren’t your own. Reserve the elevators for people with disabilities and floors higher than 10. And because it’s Twitter, naturally someone suggested that modern civilization should collapse, which would certainly get the job done.

AD

AD

And me? Glad you asked. My tax of choice is on sugar, in the supply chain. I support revamping SNAP. I’m wildly in favor of education and PE, and meh on restricting ads and front-of-package labeling. But even if we did everything on this list, I don’t think we’d have much impact on obesity, because none of this gets to what I think is the root of the problem: the simple ubiquity of food.

Several people, including Friedman School Professor Parke Wilde and New York University’s Marion Nestle, one of the most prominent voices in public health, also zero in on that problem. “Many societal changes promoted a culture in which food is available everywhere, 24/7, in enormous portions, at remarkably low cost,” Nestle told me in an email.

We can’t reverse those societal changes by government edict; societal changes are a job for society, and my No. 1 priority is harnessing public concern — and buying power — to urge private-sector changes. Nestle would start with portion sizes, and I think that’s a big one. Can we get restaurants to offer half-size entrees? Smaller soda servings? (Calorie labeling could help drive this, too.)

But we have to widen the lens. Hey, employers — could you ask whether employees would prefer to have fewer encounters with doughnuts and more chances to take the stairs? Do we really need to give kids snacks after every game in every sport? How about a no-eating-in-class rule for colleges? And, speaking of reducing snacking occasions, Wootan and CSPI are working to get candy away from check-out areas, an effort that’s bearing some fruit.

None of these is going to make us thin, but all together I think they’re our best shot at changing the zeitgeist. We all have to start thinking differently about food. Where is it okay to eat? What does a portion look like? Is dinner a chance for families to be — and eat — together? Should stores that sell clothing, or hardware, or office supplies also sell junk food? Should everyone know what to do with a bag of lentils? (Okay, maybe that last one is a pipe dream.)

AD

AD

One issue several people mentioned to me was that we should stop focusing on weight and focus on health. But if there’s one thing we know for sure, it’s that obesity is as close to a surefire precursor to health problems as anything can be. There is, of course, a subset of people who are obese and “metabolically healthy” — that is, have no risk factors for disease, like high blood pressure or cholesterol. The most recent paper on the subject was published in July, and makes the claim that those people are “not at significantly elevated all-cause mortality risk.”

But read the fine print, and zero in on the percent of obese people who fall into that category. It’s 5.8 percent, so the flip side is that 94 percent of obese people aren’t metabolically healthy. For context, it’s worth noting that the vast majority of smokers — 85 to 90 percent — never get lung cancer, yet smoking is unequivocally the single biggest risk factor for that disease. (Also worth noting is that other research finds that even metabolically healthy obese people are at higher disease risk.)

Focusing on weight is focusing on health, and the question is how we can do it in a way that is supportive and constructive and kind. The answer, I think, is to focus on the food environment that got us here. When two-thirds of us humans can’t navigate our food system successfully, we have to look for the answers in the system, not the humans.

According to Wilde, the fact that we’ve gained weight as our food environment changed tells us something. It tells us that obesity is “responsive to external conditions.” Our best hope isn’t continuing to expect people to live in this environment, but just be thin. We have to walk that environment back, evidence be damned.