By Kathryn Doyle
(Reuters Health) - On any given day, a large proportion of kids eat pizza - and on those days, they tend to eat more calories, saturated fat and sodium than they do on other days, according to U.S. data collected over the past decade.
On pizza eating days, kids ate an average of 83 more calories, and teens had an average of 230 more calories, than on non-pizza days. Kids and teens also got 3 to 5 more grams of saturated fat on pizza days, and 100 to 400 more mg of sodium.
"What this is saying is kids are not adequately compensating in other parts of their diet when they eat pizza," lead author Lisa M. Powell told Reuters Health by phone.
Powell, of the School of Public Health at the University of Illinois at Chicago, and colleagues analyzed National Health and Nutrition Examination Survey data on a national sample of kids ages 2 to 19 between 2003 and 2010, and found that calorie intake from pizza actually declined, but was still associated with unhealthier eating.
"We wanted to answer the question, 'does it matter that pizza is one of the top contributors to kids' diets?" said Powell.
It does matter, since eating pizza adds extra calories and fat to the day for the average kid, she and her colleagues wrote January 19 in Pediatrics.
Youngsters were surveyed about the food they had consumed over the previous 24 hours, twice in a ten-day period. (For small children, parents answered the questions.)
In the 2009-2010 survey, 20% of younger kids and 23% of teens ate pizza on any given day. On pizza-eating days, younger kids consumed an average of 408 calories worth of pizza and teens ate about 624 calories of pizza, which is actually less than in the 2003-2004 survey year.
That decline may be because individual kids were eating fewer slices at a time in 2010, or because the pizza itself had gotten slightly healthier, Powell said.
The American Heart Association recommends that kids age four to 18 consume between 1,200 and 2,200 calories per day, depending on their age and gender.
Snack time pizza was associated with the most extra calories, fat and salt, more than pizza eaten for lunch or dinner, the authors found.
"It has quite an adverse effect as a snack," Powell said. "Not a lot of kids are consuming pizza as a snack, but it's definitely something they shouldn't be doing."
Consumption may be going down, but portion sizes for pizza and Mexican food have both gone up over recent years in the U.S., said Barry Popkin, professor of nutrition and public health researcher at the University of North Carolina at Chapel Hill.
"It seems to me actually a worse product than it would have been 15 to 20 years ago," said Popkin, who was not involved in the new study.
"These are products that you eat only as your meal, and you tend not to eat salad as well," Popkin told Reuters Health by phone.
Pizza consumption may be on the decline in the U.S., but that is not the case globally, he said.
"If you look at pizza consumption globally, in low and middle income countries the pizza market is really exploding," he said.
Powell hopes parents will recognize the role pizza plays in their kids' diets and that pediatricians together can urge the pizza industry to make their products healthier, perhaps by lowering the saturated fat content.
"That would be a voluntary effort, but hopefully parents can use their pizza dollars to make healthier choices," she said.