Think bigger: that’s the thrust of the American Heart Association’s (AHA) new scientific statement on obesity prevention [1]. To have any meaningful impact on the obesity epidemic, clinicians need to go beyond clinical prevention and treatments for obesity and use influence and advocacy to effect social and environmental change, authors of the statement say.
“The main point of the statement is that we need to place more emphasis on population-based and preventive approaches than we have to date,” Dr Shiriki K Kumanyika (University of Pennsylvania School of Medicine, Philadelphia), lead author on the statement, told heartwire. “This point has been made in different ways before, in different kinds of documents, and it’s being made globally, but we are still in the process of educating health professionals about what this actually means and why it’s needed.… It’s inefficient to put all your eggs in the basket of screening and treating the individual.”
The statement, titled “Population-based prevention of obesity” includes an appendix listing all of the AHA’s related statements dealing with obesity published between 2004 and 2006. “It turns out when we look at all the other statements, this is a missing piece,” Kumanyika noted. “This statement is really putting the story of prevention together and pointing out that any prevention approach we take, in any population, still needs to be on a better platform,” one that takes into account public policy and social and environmental factors.”
The statement emphasizes the need for changes that would help people make better food choices and be more physically active. Examples include things like limiting the availability of high-fat, low-fiber foods and sugary drinks, reducing restaurant portion sizes, reconsidering the location of fast-food restaurants, and thinking more creatively about community design and infrastructure to enhance “walkability” of neighborhoods and commutes between home, school, and recreation.
“In a way it’s like the tobacco scenario, when people realized there were some broad policies that could be made that would change the options that people had,” Kumanyika explained. “With food it’s trickier, because food is not inherently harmful, so it’s a much more complicated task. We’re not trying to turn people against food, we’re not trying to put the food industry out of business – where would we be if we did that? But we’re trying to say that we’ve got to think more carefully about the health effects of a lot of the decisions we make about transportation, about community design, about food, about the school day, about what happens at a work site: that’s the point about the comprehensive approach. We’ve got to go into the population and make it just easier for people to bump into the right choices.”
Beyond the stethoscope
Kumanyika agrees that these points have been made before, but she says the AHA’s goal in wading into the fray was to make it clear to clinicians that they have a bigger role to play.
“This statement is about putting the information in one place and telling people who don’t think it’s their business that the level of advocacy and awareness we need also applies to them. We can’t afford to have anyone working on cardiovascular disease who, if asked by the person next to them on the golf course or next to them in the hospital, doesn’t really get it that obesity is not just a bunch of people who overindulge.”
At the very least, she says, cardiologists and clinicians need to understand the political, social, and environmental underpinnings of the obesity epidemic and make sure that they don’t “contradict” the efforts at meaningful change. “I’ve had cardiologist colleagues joke with me in the cafeteria line when they’ve got a pile of fried onion rings on their tray and they say, ‘Oh don’t worry, we’ll get them in the cath lab,’ ” Kumanyika told heartwire. “We can’t afford to have the people who are involved in treatment think that’s the only solution. They also have to convince people to do things that are a lot harder, because they’re getting right to the heart of how people live, they’re getting into vested interests, and there’s not necessarily a profit motive. But cardiologists are very, very authoritative and influential people. People will ask their cardiologist for an opinion, and we want them to know what they should say.”
Preventing obesity: action points
The stated aims of the new AHA statement are to:
- Increase awareness of population-based efforts to prevent weight gain in kids and adults.
- Detail ways of preventing obesity across the population and in higher-risk subgroups.
- Distinguish between clinical prevention/treatment and environmental and policy approaches.
- Consider the “multiple layers of influences” on what people eat and how they act, in order to identify environmental and policy-change targets.
- Identify potentially relevant interventions and what kind of evidence is needed for population-based approaches.
Kumanyika acknowledged that is it difficult for some clinicians to connect the dots and appreciate how their actions can influence political decision-making, urban planning, etc, but she also emphasizes that major grassroots and community-based initiatives are already making headway in pockets around the US. She says physicians should not underestimate the importance of their own influence in helping these kinds of movements succeed.
“There was a time when people thought it wasn’t possible to change the type of fat people eat or that you couldn’t change smoking habits,” she says. “So you have to start somewhere with that conversation, to begin to shift the expectation that these things can’t be changed. There are people who are out there, working on the ground with community coalitions fighting for this, and physicians need to help reinforce what those people are doing by lending their authority and helping to support their message.”
She continued: “There is a lot of grassroots activity, there is stuff going on all over the country with people taking on planning commissions, school boards, and advertisers. So this is actually happening, it’s a social movement. And we want cardiologists to know about it and put their weight behind it.”
Source
Kumanyika SK, Obarzanek E, Stettler N, et al. Population-based prevention of obesity. The need for comprehensive promotion of healthful eating, physical activity, and energy balance. A scientific statement from American Heart Association council on epidemiology and prevention, interdisciplinary committee for prevention (formerly the expert panel on population and prevention science). Circulation 2008; DOI:10.1161/CIRCULATIONAHA.108.189702. Available at: http://circ.ahajournals.org.
Clinical Context
Obesity has become an epidemic in the United States. The population is moving away from the Healthy People 2010 objectives of achieving less than 15% prevalence of obesity in adults and less than 5% in children. Although many guidelines have recommended clinician approaches to the prevention of obesity, none have focused on community and population-based approaches with influence on policy.
This is a review from the AHA that focuses on population-based prevention efforts from a US public health perspective, with the objectives of raising awareness about the public health approach; identifying at-risk subgroups for targeting interventions; and differentiating between community, environmental and policy approaches.
Study Highlights
At-risk populations
- In children and adolescents up to age 20 years, the term overweight vs obesity is used by the Centers for Disease Control and Prevention and is defined as a body mass index at or above the 95th percentile of sex-specific body mass index for age values from the Centers for Disease Control and Prevention 2000 growth charts.
- Children and adolescents are at risk for obesity in adulthood.
- Waist circumference percentiles are available for white, African American, and Mexican American children, but there is insufficient evidence for routine clinical use of waist circumference in children at present.
- Obesity prevalence is higher in some racial and ethnic minority groups including African Americans, Hispanic/Latinos, Alaska Natives, American Indians, native Hawaiians, and Pacific islanders across the adult age spectrum.
- The prevalence of obesity is higher in female sex in some and in both female and male sex in other groups.
- Ethnic disparities in obesity apply to both body mass index and waist circumference.
- Sex differences in obesity reflect differences in attitude toward food and nutrition, household role in food purchase, and cooking and cosmetic effects of obesity.
- People with mental and physical disabilities are a subpopulation at increased risk for obesity.
- Adults with Down’s syndrome, those who have hypotonia, and those who use antipsychotic medications, for example, have a higher prevalence of obesity.
- Community, environmental, and policy approaches
- Rural, urban, and suburban differences in obesity may reflect socioeconomic differences, with a higher prevalence of obesity in the lower socioeconomic groups.
- The prevalence of obesity among adolescents and children does not follow age, sex, and ethnic trends as in adults.
- Both higher and lower birth weights are associated with later obesity and its adverse consequences.
- Population-based prevention can reach individuals through different routes other than traditional health services delivered in the clinical encounter.
Community design and infrastructure may dictate the level of sedentary activity in a community.
- Land use mix and street connectivity can influence physical activity.
- Selective prevention of obesity is an approach to target high-risk groups with the use of strategies such as motivational messages, policy, and social change.
- Access to supermarkets can be associated with better dietary quality, and access is lower in census tracts with a high proportion of African American residents.
- School meals and access to healthy snacks in vending machines can influence the prevalence of obesity among children.
- A multilevel, multisectoral approach is recommended with use of a “causal web” of societal influences on obesity.
- Population approaches should go “upstream” to focus on environmental and policy change to reduce obesity.
- For example, healthcare providers can influence the community design of recreational facilities, automobile use, and availability of public transportation to affect the level of physical activity.
- Options for policy change include taxation of snack foods, subsidies for fruits or vegetables, and school diets that meet nutritional standards.
- Community organizations and networks can be fostered to implement local obesity prevention strategies.
- The body mass index distribution of a community may be targeted in research studies of community-based interventions.
Pearls for Practice
Populations at risk for obesity include children and adolescents, ethnic minorities, women, and people with mental and physical disabilities.
Providers can effectively participate in population-based strategies that address community, environmental, and policy change to reduce obesity.
