How much fast food do children eat?

Using data for 12,378 children in the 2003–2010 cycles of the nationally representative National Health and Nutrition Examination Survey (NHANES), study co-author Colin Rehm (now a postdoc at Tufts University) devised an algorithm that divided FFRs into the seven segments by which the industry classifies itself—burger, pizza, sandwich, Mexican, Asian, fish and coffee/snack restaurants—and assigned meals and snacks to each.

“Once you assign a sentinel food to a given type of restaurant, you can then assign all the calories from that meal to that restaurant," ​study co-author Adam Drewnowski told FoodNavigator-USA. "The interesting part about that was it was not just the consumption of say, pizza that counted, but consumption of pizza and a soft drink in a pizza restaurant that counted.”​ 

The researchers assessed the contribution of each restaurant type to intakes of energy and other dietary constituents by age group (4-11 years and 12-19 years) and by race/ethnicity. They found that, contrary to the perception that children in the US get a significant amount of calories from fast food, FFRs provided just 14.1% of calories, 15.9% of sodium, 10.4% of added sugars and 17.9% of solid fats. Store-bought foods and beverages, on the other hand, accounted for 64.8% of calories, 61.9% of sodium, 68.9% of added sugars, and 60.1% of solid fats, according to the analysis.   

When broken down by segment, burger restaurants led the FFR category, with 6.2% of total calories, 5.8% of sodium, 6.2% of added sugars, and 7.6% of solid fats. Pizza (3.3%), sandwich (1.4%), Mexican (1.3%), and chicken restaurants (1.2%) followed. The researchers also found that non-Hispanic black children obtained a greater proportion of total calories (7.4%), sodium (7.1%), and solid fats (9.5%) from burger restaurants as compared to non-Hispanic white children (6.0% of calories, 5.5% of sodium, and 7.3% of solid fat).

Algorithm relies on consumption data, not just menu analysis​

What makes the algorithm unique from previous analysis of FFR’s contributions to the diet is both its basis in representative federal data and that it relies on actual consumption data, rather than menu offering analysis, Drewnowski noted.  

“This was based on representative NHANES data, which is a federal database used to guide policy by policymakers. Here we have some population validity applied to this population,” ​he said. “Second, this is a way of looking at the evolving contribution of FFR based on actual consumption data and not on analyses of menu offerings. Virtually every study in literature analyzes menu offerings to determine whether sodium increased or decreased, or changes in main meals or side dishes. This is a way of actually looking at sales data by restaurant segment. That’s very novel.”​

Not only can the tool offer better insight into what is actually eaten at FFRs, but it can also help monitor the effectiveness of the industry and public health policies aimed at improving children’s eating habits. But it’s a two-way street, Drewnowski noted, as accurate information is equally reliant on updated data from the industry.

“This gives us a tool to monitor compliance with Dietary Guidelines. So we can examine, for example, who has reduced sodium? Chicken, Asian or seafood restaurants? It provides an ​interesting way to monitor, but it has to be supplemented with updated databases. For example, if your fried chicken has less sodium, that needs to be reflected in USDA database sooner rather than later. In order for us to see changes the in menus, the menu compositon database has to be updated regularly."​

Source: PLOS ONE
DOI: 10.1371/journal.pone.0103543​
“A New Method to Monitor the Contribution of Fast Food Restaurants to the Diets of US Children”
Authors: Colin D. Rehm and Adam Drewnowski