There is an odd disconnect between the way that we talk about obesity and how we help people manage their weight. Experts emphasize the complexity of the problem and the fact that causes can vary from person to person. Obesity is ultimately determined by how many calories you eat and store, versus how many calories you burn through exercise. Harvard Medical School explainsEach of these factors can be influenced by genes and the environment.
Both can impact your physiology (such how fast you burn calories) and your behavior (the foods you choose to eat). All these factors interact at every stage of your life, starting at conception.
This nuance is lost when we talk about possible solutions to obesity. According to the American Heart AssociationAHA) has implemented educational interventions (e.g. Obesity has not been reduced by calorie counts on menus. The solution lies in changing our food environment. AHA asserted:
Theoretical and scientific support is growing for policies that target environmental determinants of obesity. Some policies are being opposed by the food and beverage industry. Behavioral economics has shown that humans are greatly affected by their environment.
It has been almost ten years since the AHA published its November 2012 paper. This has given us ample time for further research into the effectiveness of these interventions. The studies that have been done lead to two conclusions.
First, interventions that change our environment, such as limiting access to vending machine, don’t help to reduce obesity. The second is that the researchers who reported these results seem to be certain that we need more restrictive measures to achieve positive outcomes. Both results indicate that we need a new approach to reducing obesity.
What are the results of these studies?
Let’s start with September 2021, because obese children often become obese adults. Literature reviewExamining efforts to reduce the calorie intake of adolescents. The authors reviewed 52 trials published between 2009-2019. Each paper looked at school-based, community-based, mass media interventions, and interventions in the food sector.
Many of these were educational (e.g., nutrition courses for parents and students), but nine studies looked at interventionist policy like school menu changes and increased physical activity during school hours. Results:
“Overall, the majority of intervention studies did not show consistent results in changing children’s BMI. A large number studies, mainly focused on school interventions, did in fact not show very significant results. The small weight reductions reported in many studies could have been clinically irrelevant.
These disappointing results could be explained by a variety of factors, the authors wrote. They could have missed the success of certain policies because they were not well-designed. A trial might not have been long enough. They also acknowledged the possibility of these interventions not working, but they came to a strange conclusion.
Complex and multilevel interventions focusing on environmental change and the strengthening of individuals, families, and communities as well as macro-policy modifications will have the potential for tackling childhood obesity without increasing socioeconomic disparities.
It is not clear to me how they got there. All of the multilevel interventions that they looked at did not reduce childhood obesity. The world needs more multilevel intervention. Why is this? “Show us your work, please,” were the words of my math teachers.
This discrepancy between what data researchers claim and what the data actually reveal is common in obesity policy literature. A June 2019 Cochrane Collaboration Systematic reviewExamining policies to reduce sugary beverages intake revealed that there are effective and scalable interventions that address SSB. [sugar sweetened beverage]Consumption at a population level exists.
These interventions included price hikes on soda, reduced access for SSBs in schools, as well as restrictions on urban planning that would prevent new fastfood restaurants from being built. Weighing in on the evidence to support these policies was not conclusive. The authors reviewed 58 studies and found that none of them were conclusive.
Only seven studies have reported any effect on bodyweight outcomes. The evidence included in this review is limited in quality, quantity, scope and scope. Reporting bias was a concern. The majority of the studies included in this review did no provide information about trial registration, protocol availability, or prespecification for outcomes and analyses.
PloS One published a Jan 2022 study that acknowledged what few other researchers are willing admit to: There is There is very little evidence regarding the effectiveness of policy-based interventions for obesity at the population level or in relation to multilevel or societal interventions in the UK. We have surveyed studies from many countries so it is not necessary to limit our conclusions to the United States. These policies have not worked wherever they have been implemented.
The authors proposed a model that would simulate hypothetical calorie-reduction programs on obesity. They also emphasized the role of social determinants in determining outcomes. However, their models showed that childhood obesity fell from 18.3% to 16.8%, i.e. an 8.3% decrease. That was the largest effect they could find in any of their models.
What’s the solution?
It is clear that interventions to change the public’s eating habits have not been very successful. That raises many questions. Why do obesity experts continue advocating policies that don’t work? These policies don’t work. Let’s look at what might actually work. In part two, we’ll address these issues.
