Is it possible to be scared into better health?

Officials at the New York City Department of Health and Mental Hygiene hope so. They’ve launched a startling new poster campaign intended to warn the public against obesity.

The poster depicts a man with Type 2 diabetes and an amputated leg with a graphic that shows how sizes of soft drinks have increased over time. The accompanying text reads: “Portions have grown. So has Type 2 diabetes, which can lead to amputations. … Cut your portions. Cut your risk.”

As the health department explained in an e-mail, the goal of the campaign, launched last week, is “to provide an evidence-based, realistic representation of the health consequences of excessive portion sizes.”

Realistic though those consequences may be, New York is clearly taking a shock and gross-out approach to its battle against obesity. And as Canadians will recognize, it’s not unlike the tactic Health Canada uses in its graphic warning labels on cigarette packages.

The question is, does it work?

A 2009 report by the International Tobacco Control Policy Evaluation Project noted that 91 per cent of smokers in Canada read tobacco warning labels and 84 per cent of smokers viewed them as a source of health information, after the country introduced large graphic anti-smoking labels in 2001. The Waterloo, Ont.-based international study also said health warnings, particularly large pictorial warnings, can promote smoking cessation. And although repeated exposure can reduce their effect over time, the report suggested vivid warnings are more likely to retain their salience.

“There is data that suggest shock tactics do in fact help in reducing smoking rates,” says Yoni Freedhoff, an obesity expert who directs the Ottawa-based Bariatric Medical Institute, “so it might follow that they’d be useful with soda as well.”

The poster of the man with an amputated limb is only the latest disturbing campaign launched by the U.S. city. In 2009, the health department famously made television audiences squeamish with spots showing a man opening a soda can and pouring from it, then drinking a glass of yellow goop resembling human fat. A separate ad showed a man gulping packet after packet of straight sugar to illustrate how much sugar is in sweetened drinks.

As waistlines everywhere are expanding, other jurisdictions have also considered resorting to scare-them-slim tactics. Last year, the Australian Medical Association reportedly proposed to develop anti-obesity advertisements modelled after New York’s. And in recent weeks, the Strong4Life movement by the non-profit Children’s Healthcare of Atlanta has been making headlines for its “stop childhood obesity” ads, which show various unhappy, overweight children speaking about the social and physical consequences of their weight.

In one spot, a child referred to as “Jaden,” sullenly explains: “I play video games. That’s what I like to do. I don’t have to be around other kids. Because all they want to do is pick on me.”

According to Toronto marketing expert Alan Middleton, these kinds of blunt strategies meant to threaten people into changing their health habits do, in fact, work, but only on people at the low end of the risk.

“It’s most likely to [work with]people who are worried about it, who may be either trending slightly toward overweight with themselves or their family, or just paranoid about being this way,” says Dr. Middleton, who is an assistant professor of marketing at York University’s Schulich School of Business. “What it won’t work with … is with the people with the significant problems and the significant risk.”

The reason those at greatest risk aren’t swayed by shock ads is because they tend to block out such warnings.

“People, by and large, say ‘I know, I know, just don’t tell me. I need another cigarette to help me. I need that pork pie. I need to go to McDonald’s,’ ” he says, noting that aggressive ads can elicit more avoidance of any behavioural change.

Shock campaigns may not make their health problems any worse, he says, but “it certainly doesn’t make it better.”

In fact, he says, some companies have managed to cash in on people’s rebellion against health warnings, such as the British cigarette brand Death, which was one of the hottest-selling cigarette brands among teenagers in the 1990s, and, more recently, KFC’s overtly indulgent Double Down.

Dr. Middleton says anti-obesity campaigns would be more effective if they focused on how people can take small steps that accumulate to sustainable behavioural change. After all, he says, it’s not their attitudes about obesity that need changing; it’s their behaviour. People who go on crash diets out of panic, for instance, rarely succeed in long-term weight loss.

One weight-loss marketing tactic that’s on the right track can be seen in ads that show models saying, “I lost a certain amount of weight,” because they convey the message that it can be done, Dr. Middleton says.

Unfortunately, too often, instead of showing moderate weight loss, most of these ads show an exaggerated amount of weight loss, he says.

“In the point of exaggeration, it begins to lose credibility.”