About a third of the calories kids eat at
school, at fast food restaurants and from grocery stores are "empty
calories" that should be targeted for reduction, according to a new study.
"Although fast foods are generally
recognised as less healthful, our study found that foods consumed by US
children from grocery stores and schools were similar in empty calorie content
to fast foods," author Jennifer M. Poti said.
Poti is a doctoral candidate in nutritional
epidemiology at the University of North Carolina at Chapel Hill. The 2010
Dietary Guidelines for Americans recommend for kids and adults that a maximum of between 8% and 19% of their daily calories should be "empty",
that is, coming from added sugar or solid fat.
Solid fats include those solid at room
temperature, including butter, meat fats and hydrogenated oils. Added sugars
are incorporated during food processing, preparation or at the table, but do
not include the natural sugars in fruit or milk, Poti said.
These fats and sugars add lots of calories
but few nutrients to food. Getting too many empty calories can lead to weight
gain and obesity, she said.
The new study, which analysed data from a
2010 nationwide survey covering more than 3 000 kids ages 2 to 18 years old,
looked at the calories consumed from three primary food sources: grocery or
convenience stores, schools and fast food restaurants.
At each location, about a third of the
children's average calorie intake was "empty calories". In food
purchased from stores, 33% of calories were from fats and added sugars. In food
from fast-food restaurants, it was 35%, and school-bought foods were 32% empty
Kids tended to get most of their food from
stores, so that location provided the highest total empty calories an average
of 436 calories daily according to the results published in the Journal of the
Academy of Nutrition and Dietetics.
Sugary drinks and grain-based desserts like
cakes were big empty calorie sources at each of the locations. Whole or two
percent milk was also a common source from stores and at school. The study also
pointed the finger at pizza from schools and pizza and French fries from
restaurants as major contributors to daily totals for empty calories.
Store-bought foods tended to have more
sugar and less fat, whereas the reverse was true for fast foods. School food
fell in the middle on both counts."Our study found that 20% of pizza and
22% of high-fat milk consumed by kids are provided by schools, and 72% of
sugar-sweetened beverages like sodas, fruit drinks, sports drinks and energy
drinks consumed by kids are obtained from grocery stores," Poti said.
Efforts to improve kids' diets should be
aimed at all three locations, she said. Since the top empty-calorie food
sources were different at the three locations, strategies to reduce empty
calories may need to vary by location, she said.
"The data analysed in our study was
collected before implementation of the new nutrition standards for the National
School Lunch and Breakfast Programs, established by the Healthy, Hunger-Free
Kids Act of 2010," Poti said.
These results could be an important
baseline for gauging how effective more recent changes have been, she
said."The new US Department of Agriculture lunch rules that went into
effect last year require only lower-fat milks, and proposed standards for
vending machines and other venues also require lower-fat milks, but those
standards have not yet gone into effect," said Lindsey Turner, a health
psychologist and research scientist at the Institute for Health Research and
Policy at the University of Illinois at Chicago.
"In our Bridging the Gap research
studies of K-12 schools nationwide, we found that even just two years ago, many
schools offered higher-fat milks at lunch," said Turner, who was not
involved in the new study, but has conducted similar research in schools.
Pizza is available most days or every day
in most high schools, she said. "It will be essential to keep tracking
whether schools are implementing the new nutrition standards and removing
unnecessary sources of sugar and fat that contribute to empty calories for
children and adolescents," she said.
Current guidelines don't require added
sugar or solid fats to be indicated on nutrition facts panels for packaged
foods. But parents can keep track of saturated and trans fats, which are the
main types of solid fats, and total sugar levels which are included on labels,
The recent Food and Drug Administration
ruling that trans fats are no longer "generally recognized as safe"
could help to reduce children's empty calorie intake if trans fats are removed
and not replaced with other solid fats, she said.