Governments could slow — and even reverse — the growing epidemic of obesity by taking measures to counter fast food consumption, according to a study published today in the Bulletin of the World Health Organization.
Led by Roberto De Vogli of UC Davis, the study showed that fast food purchases were independent predictors of increases in the average body mass index (BMI) in the U.S. and 24 other wealthy nations from 1999 to 2008. Nations with stronger government regulations — such as producer protection, price controls, and stronger intervention on competition and taxes — experienced slower increases in fast food purchases and average BMIs.
De Vogli’s research is the first to look at the effects of deregulation in the economy, including the agricultural and food sectors, and the resulting increase in fast food transactions and BMIs over time. It suggests that if governments take action to control food industries, they can help prevent overweight and obesity and its serious health consequences, including cardiovascular disease, diabetes, stroke and diet-related cancers.
"Unless governments take steps to regulate their economies, the 'invisible hand of the market’ will continue to promote obesity worldwide with disastrous consequences for future public health and economic productivity," said De Vogli, associate professor in the UC Davis Department of Public Health Sciences.
Rather than looking at the density of fast food outlets or self-reported fast food consumption as researchers have done in the past, De Vogli and his colleagues compared data on fast food transactions per capita with figures on BMI, which is a standard measure of body fat based on height and weight. A person with a BMI of 25 to 29.9 is considered overweight, while a BMI of 30 or more is considered obese.
The study focused on high-income countries, but the findings are also relevant to developing countries as "virtually all nations have undergone a process of market deregulation and globalization — especially in the last three decades," De Vogli said.
The authors of the study found that while the average number of annual fast food transactions per capita increased from 26.61 to 32.76, average BMI increased from 25.8 to 26.4. Thus, each 1-unit increase in the average number of annual fast food transactions per capita was associated with an increase of 0.0329 in BMI over the study period.
The BMI figures revealed that the problem of unhealthy weight is widespread; people living in the all 25 countries included in the study were, on average, overweight.
The average number of annual fast food transactions per capita increased in all 25 countries. The sharpest increases were in Canada (by 16.6 transactions per capita), Australia (14.7), Ireland (12.3) and New Zealand (10.1), Norway (9.0) and the U.S. (8.6), while the lowest increases were in countries with more stringent market regulation, such as Italy (1.5), the Netherlands (1.8), Greece (1.9), Belgium (2.1), Portugal (2.6) and Spain (3.4).
"It’s not by chance that countries with the highest average BMIs and fast food purchases are those in the forefront of market liberalization," said De Vogli. "Whereas countries with lower average BMIs and fewer fast food transactions have some of the tightest controls on food economies."
"This study shows how important public policies are for addressing the epidemic of obesity," said Francesco Branca, director of the Department of Nutrition for Health and Development at the World Health Organization (WHO). "Policies targeting food and nutrition are needed across several sectors, including agriculture, industry, health, social welfare and education. Countries need to take action to align the food supply with the health needs of the population."
The study authors also found that increases in BMIs could not be explained by increases in animal fat consumption or total calories, which remained close to constant over the course of the study.
"This was surprising," De Vogli said. "Fast food tends to be high in animal fats, which have been linked to unhealthy weight. The only factor that can partially explain the BMI increases is soft drink purchases."
De Vogli recommends that future research focus on categorizing food items according to levels of processing instead of fats and calories, which could help identify the specific determinants of overweight and obesity.
"The next step will be to study in detail what is done with food and how those processes alter calorie and nutrient content along with health," De Vogli said.
In addition to De Vogli, the study authors were Anne Kouvonen of Queen’s University in Belfast and David Gimeno of the University of Texas Health Science Center in Houston. Their study, titled "Fast Food, Body Mass Index (BMI) and the Role of Market Deregulation: A Cross-National Time Series Analysis," is available at http://www.who.int/bulletin/en/
The research was funded by a grant from the Economic and Social Research Council in the United Kingdom.
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The Bulletin of the World Health Organization is one of the world's leading public health journals. It is the flagship periodical of WHO, with a special focus on developing countries. Articles are peer-reviewed and independent of WHO guidelines. Abstracts are available in the six official languages of the United Nations: Arabic, Chinese, English, French, Russian and Spanish. The complete content of the journal is available free to readers worldwide through PubMed Central at http://www.pubmedcentral.nih.gov/tocrender.fcgi?journal=522