After a period of improvement, U.S. kids are eating as much fast food as they were in the early 2000s, new government figures show.
Researchers found that between 2003 and 2010, there was a decline in U.S. kids' intake of fast-food calories -- dipping from an average of 14% of daily calories, to just under 11%.
The positive trend was short-lived, however. By 2018, that figure was back up to 14%.
The study, by the U.S. National Center for Health Statistics (NCHS), did not go into the underlying reasons. But other research gives some clues as to what could be driving the reversal.
One possibility is that social media and "digital marketing" have a role, according to Frances Fleming-Milici, a researcher with the Rudd Center for Food Policy and Obesity at the University of Connecticut.
"Fast-food companies have been pioneers in using digital marketing," said Fleming-Milici, who was not involved in the NCHS report.
Admittedly, she said, it is hard to get a handle on how often kids encounter fast-food promotions on their smartphones.
But a recent Rudd study found that 70% of teens "engaged with" food and beverage brands on social media -- meaning they followed the brands, or "liked" or shared their content. More than half of kids said they engaged with fast-food brands.
Another Rudd study found that the percentage of parents buying fast food for their kids rose between 2010 and 2016. By 2016, 91% of parents said they'd bought their children meals in the last week at one of the four largest fast-food chains in the United States.
In recent years, Fleming-Milici said, fast-food companies have been promoting "healthy" side-order and drink options for kids. And in the study, most parents intended to buy fast food more often because of those policies.
Yet there was no evidence parents were actually buying more of those healthy options in 2016, versus 2010.
The new findings, released in an Aug. 14 data brief, are based on responses to an ongoing federal health survey. Every couple of years it asks a nationally representative sample of Americans about their health and lifestyle habits.
It found that between 2015 and 2018, more than 36% of all 2- to 19-year-olds consumed fast food -- with teens being bigger consumers than younger kids.
There were racial differences, too. Among teens, white kids downed an average of 15% of daily calories from fast food. That rose to 18.5% of Hispanic teens, and 21.5% of Black teens.
Food companies, including fast-food restaurants, have increased their marketing on Black-targeted TV, according to Fleming-Milici. And in 2017, Black teenagers saw twice as many food ads on TV as white teens did, she said.
If U.S. kids are eating more fast food, there's reason for concern -- since the traditional burger-and-fries meal is typically loaded with fat, sodium and sugars.
"Foods that tend to be high in calories and fat, if consumed on a regular basis, can contribute to childhood obesity," said Kristi King, a pediatric dietitian at Texas Children's Hospital in Houston.
Beyond obesity, there's also the matter of kids getting the nutrients they need. If they are filling up on fat and sugar, that can displace nutrient-rich foods, said King, who is also a spokeswoman for the Academy of Nutrition and Dietetics.
Plus, she added, childhood is a time when people can develop lasting habits around food. If kids learn that grabbing fast food is the norm, they'll likely carry that into adulthood.
If parents are hard-pressed for time, homemade meals do not have to be laborious, according to King. She offered some tips for making things easier: Get some meal preparation done on the weekends -- even just chopping up vegetables -- so there is less to do on weeknights; do some "DIY" meals, where everyone makes their own individual salads, tacos or mini-pizzas, and get the kids involved in prepping and cooking.
"Making it a family affair can help save time and teach kids skills that will last them a lifetime," King said.
The Nemours Foundation has advice for parents on healthy eating.