US adults have been eating more highly processed junk food over the past two decades, according to a national survey.
at New York University and her colleagues analysed data from a yearly survey that has been carried out since 2001. Each year, the survey asks a nationally representative group of 5000 US adults to recall what they had eaten in the past 24 hours.
The team categorised foods into four groups based on the level of processing that had been applied to them, from minimally processed foods, which include fruits, vegetables and parts of animals such as steak, to ultra-processed foods, which include ready meals, breakfast cereals and fries. They estimated the proportion of the total daily energy intake provided by the four groups.
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The team found that ultra-processed foods made up 53 per cent of the daily energy intake of US adults in 2001, and this steadily increased to 57 per cent by 2018, the most recent year data was available.
“This is the most long-term study of the trends in the US population consumption [of processed foods],” says Juul.
Although a causal link between eating highly processed food and weight gain was recently shown in the , “there aren’t really policies that address this type of food as a group”, says Juul. This is partly because, until now, recent trends in ultra-processed food consumption in the US were unclear.
“The increased consumption of ultra-processed foods may be a key driver of the pandemic of chronic diet-related diseases, such as obesity, cardiovascular diseases and diabetes,” says , who researches the effects of ultra-processed food on health at Tufts University, and who wasn’t involved in the new study.
The team found that ultra-processed food consumption is lower in certain groups based on ethnicity and education level.
“In terms of ethnicity, both non-Hispanic white and non-Hispanic Black Americans eat more ultra-processed foods than Hispanics,” says Juul.
When the team controlled for income level they found that “people with a college degree eat less ultra-processed foods than people with lower education levels”, says Juul.
A better understanding of which parts of the population are eating more highly processed foods will help to guide policy-making.
“You want to know that you’re putting in place the right policies and interventions in order to really help the groups that need it the most,” says Juul.
A better understanding of the data will help too. “We classified everything according to processing level and sometimes there’s just not enough information and details available about the food to determine processing level with 100 per cent certainty,” says Juul.
To address this, the research team used a conservative approach that tended to assign a given food to the lowest possible category of processing.
“Thus, the actual consumption level of ultra-processed foods could be even higher than reported,” says Wang.
The American Journal of Clinical Nutrition
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