Background
In most high-income countries, we eat too much . Looking around the world, it appears that obesity parallels economic development. Within countries, there is a more mixed picture, but there are few people actively choosing to be overweight. In fact, weight gain has occurred against strong cultural pressure to be thin, widespread knowledge of the harms of being overweight, and many people actively spending time and money trying to control their weight .
The Health Survey for England suggests that almost half of the adult population is trying to lose weight at some point. However, despite this, there is a persistent belief among the public and policymakers that the solution is more education and urging people to make the right decisions .
Public health prevention policies should not be confused with interventions to support meaningful weight loss treatment for people living with obesity. The latter is best achieved with individual support and specific weight loss programs. But successful prevention of primary weight gain or secondary recovery will also be supported by an environment that does not encourage overconsumption .
Create a supportive food environment
How can we do this?
Research clearly shows that we overvalue individual decision making and underestimate the impact of the environment on our behavior.
Consider our study in which a supermarket removed chocolate from prominent placement in selected stores in the run-up to Easter, although the products were still available for sale elsewhere in the store. Before the experiment, chocolate sales in these stores and the matched controls, where chocolate was promoted as usual, were similar. In stores with less prominent positioning, people bought 12% more chocolate in the period before Easter than during the period before, while in stores with (typical) designs they bought 31% more. In the intervention stores, people put fewer calories in their baskets than in the control stores. Modern food shopping environments are set up to maximize profits and not health .
Perhaps we could learn to be hypervigilant when shopping, but this requires a level of executive functioning ( ’willpower’ ) that is more than we can reasonably be expected to mobilize at any moment of the day, especially when we are stressed or distracted. Food cues are embedded throughout our environment . Furthermore, they condition our behavior in much more subtle ways than we consciously recognize. In another experiment , children watched advertisements for food or toys before a cartoon. Later, they were offered a selection of foods to eat. Compared to children who watched television without food ads, children who watched food ads ate more. The same thing happened when children saw a celebrity on television associated with potato chip ads, even though no food was shown. People are unlikely to perceive that their "choice" in these and similar experiments has been determined by the environment. So why is this happening?
The UK government’s Foresight report on obesity in 2007 described a reinforcing loop in which biological hunger signals dominate over much weaker satiety signals. What evolved as a survival strategy now leaves us vulnerable to an environment where food is palatable, available, and highly commercialized. Weight gain is an almost inevitable consequence in economically advantaged countries, but we reproach ourselves for the lack of willpower . More importantly, our society, expressed through the action of our legislators, continues to believe that people have more control over their choices than they actually do. This thinking shapes political discourse and presents a challenge to the introduction of policies that are seen as limiting the "free market" .
Accepting the need to change our food environment is crucial to moving towards healthier weight societies.
This is not something that individuals can do alone. In the mid-20th century, the food industry worked to provide more food to more people at a lower price after a period when the main threat was malnutrition , but the market needs a reset to meet current health needs. That will likely require government intervention to encourage and support progressive businesses during a time of change. The tax on the soft drinks industry in the UK provides a good example of what can be achieved. By encouraging the reformulation of soft drinks, sugar intake from the drinks was reduced by 30% without decreasing sales. This small change in the environment is predicted to decrease the prevalence of obesity by 0.2-0.9% and the incidence of type 2 diabetes by 0.8-4.4/1000 person-years.
Just as no change in the environment created the high prevalence of obesity, no policy can reverse that change. We need to accumulate policies, as we have done in tobacco control, to reverse the environmental impact of the changes that have led to overconsumption. This requires sustained action, beyond the usual political cycles.
But currently, standing between us and a healthier environment is political inertia. We postulate that our strong belief, arising from our daily experience of our self-conscious being, leads us to consider our behavior to be consciously governed because we fail to notice the countless times a day that the environment changes what we do. While we may accept the intellectual argument that advertising works, we tend to see the effects of advertising as much greater on others than on ourselves, and therefore our belief about the conscious drivers of our own behavior remains intact. Furthermore, as citizens or as legislators, we have a strong moral belief that behavioral change must come from within and that external factors are somehow secondary ways of changing behavior.
Conclusions We have strong evidence that tax policies, advertising restrictions, and reduced availability of unhealthy products change behavior , and there is no shortage of policy documents that recommend specific interventions to prevent obesity. However, only a few are enacted anywhere in the world. Explaining the neurobiological basis of behavior does not seem to change our view that we are masters of our own destiny , but highlighting everyday experiences when our food ’choices’ are shaped by the environment may be more persuasive in explaining why the ’choices’ model willpower’ is defective and, consequently, opens the door to more effective political action. |
*The authors Jebb, SA, Aveyard, P. are part of the research team at the Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
