Moş Gheorghe's Lunch

Fast Food and Obesity, Presumptions and Facts

Fast food and junk food are slippery and pejorative terms that many people equate with a risk of obesity. Most people – even people who routinely consume it – presume that fast food is not good for health. With the release of Super Size Me in 2004, we seemed to hit a peak in the focus on fast food as the prime villain driving us to more obesity. Almost two decades later, perhaps the time is right to sort out the facts and distinguish them from presumptions about obesity and fast food.

Recent research can help us with this.

Fast Food Exposure as a Factor in Childhood Obesity

In Economics & Human Biology, Peter Dolton and Wiktoria Tafesse examine UK data. They used measured BMI from a British cohort study of children and adolescents. They also had good data on the introduction and operation of all fast food outlets in the UK. Their data deals with a time period that saw the introduction of fast food into the UK, and a subsequent rise in child and adolescent obesity. So they looked for a relationship between exposure to fast food outlets and adolescent BMI that might be causal. They found none:

“There is no evidence that the introduction of fast food induced any behavioural change which resulted in weight gain amongst adolescents in the UK in the 1980s. Our overall findings are supported by there being a decrease in total calories purchased since this time period. Thus, we suggest that it is unlikely that the access to fast food caused the start of the British obesity epidemic.”

Fast Food, Neighborhood Food Environments, and Poverty

Thomas Burgoine and colleagues analyzed the interaction of fast food exposure, diet quality, and obesity in a study of 51,361 UK Biobank participants. Here they did find a relationship, but it was one that worked in concert with poverty:

Our study demonstrated independent associations of neighbourhood fast-food outlet exposure and household income, in relation to diet and multiple objective measures of adiposity, in a large sample of UK adults. Moreover, we provide evidence of the double burden of low income and an unhealthy neighbourhood food environment, furthering our understanding of how these factors contribute jointly to social inequalities in health.

In Social Science and Medicine, Petya Atanasova and colleagues published a systematic review with similar implications.

Implications for Policy

In many areas, local governments have dabbled with zoning regulations to restrict access to fast food. Such efforts have had little or no effect on fast food consumption or health outcomes. We are not surprised because other factors are likely at work in driving fast food consumption. Time stress and poverty are surely in play. Addressing just part of the puzzle will not solve it. Nor will demonizing food that people enjoy.

Perhaps the time has come to set aside presumptions that fast food is a driver of obesity rates by itself and look a little deeper for more complete explanations.

Click here for the study by Dolton and Tafesse, here for the Burgoine study, and here for the Atanasova review. For perspective on zoning restrictions to target fast food, click here.

Moş Gheorghe’s Lunch, painting by Rudolf Schweitzer-Cumpana / WikiArt

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August 20, 2022