Children who frequently eat out score worse on measures of cardiovascular disease risk than those who eat more meals at home, researchers reported at the American Heart Association's Scientific Sessions 2005.
"As a culture, we say we value physical activity and healthy eating, but in reality we're all about convenience and convenience foods because we have such busy schedules," said study author Karen Olson, R.N., executive director of the Cardiovascular Research and Education Foundation in Wausau, Wis.
"We are seeing younger and younger patients with more aggressive cardiovascular disease, and we realized we needed to take a closer look at our young people to see when risk factors emerge and why," she said. "We're concerned because we know that children who have cardiovascular risks grow up to be adults who have these risks."
The project initially included 759 participants, but only 621 completed the diet and exercise surveys. Researchers examined these remaining participants to find out the relationship between the development of cardiovascular disease (CVD) risk factors and eating outside the home.
Researchers randomly selected students in the 2nd, 5th, 8th and 11th grades who participated in the Wausau SCHOOL (School Children Have early Onset Of Leading risk factors for CVD and diabetes) Project, an examination of the development of risk factors for CVD and diabetes.
The SCHOOL project earlier found that 40 percent of the children followed had at least one lipid abnormality.
Twenty-percent of the students (126) indicated that they had eaten out four or more times weekly, not including lunches in the school cafeteria.
Compared with the 495 students who ate out less than four times a week, those who dined out often had significantly:
Higher systolic and diastolic blood pressure. Systolic blood pressure (the top, higher number) measures the force on the arteries when the heart is contracting. Diastolic blood pressure is the pressure when the heart is at rest between beats.
Lower levels of high-density lipoprotein (HDL) -- the "good" cholesterol that protects against heart disease.
Smaller LDL particle size. Small, dense LDL particles are associated with atherosclerosis (a build-up of artery-clogging plaque).
Lower scores on the quantitative insulin-sensitivity check index (QUICKI). Lower insulin sensitivity is an early sign of progression towards type-2 diabetes.
Significantly overall higher dietary intake of starch, sugar, sodium, fat and cholesterol.
"Children who ate out more frequently were not significantly more overweight than their peers who ate out less frequently," Olson said. "But this might just reflect that the dietary patterns have not yet had their full impact on body weight. However, their diets and exercise patterns differed significantly from the children eating at home more often."
Researchers questioned children about their activities and, using pictures illustrating portion sizes, asked about their typical diet and what they ate during the last week.
Compared with the average consumption in the total group of children, those eating at home ate slightly less sugar, sodium, fat and cholesterol, while those eating out ate substantially more foods containing those ingredients.
"In a 21-meal week, eating out four times shouldn't create the high-sugar, high-sodium, high-fat intake that we saw," Olson said. "We think it's not just the eating out but the way these children are eating all the time, with lots of frozen pizzas and packaged macaroni and cheese on the days they eat at home."
The study did not include information about take-out foods consumed at home, so it may underestimate the number of fast-food meals consumed by the children, researchers noted.
Children who ate out more often also drank almost twice as many sodas and other soft drinks, about six cups a week compared with 3.65 cups a week for the children who ate out less often. Punch, sugary juice drinks and diet soda were counted as sodas.
"For these children, soda is no longer a treat -- it's something you have every day or several times a day," Olson said. Sodas are now banned from Wausau School District public schools but were available at middle and high schools in Wausau during the study (2002-03 school year).
According to researchers, children who ate out more often were also significantly less active than their peers.
Not counting school or time spent reading or doing homework at the computer, children who ate out more often spent an average of 3.59 hours a day in sedentary activities such as playing computer games and watching television. Children who ate out less often spent 2.78 hours a day in sedentary activities.
"I think what we've tapped into here is a whole different lifestyle," said study statistician Bryan Hendricks, Ph.D., of the University of Wisconsin in Madison.
The researchers are working on interventions to encourage more physical activity and healthier eating for children. "Ideally, we can teach people the skills to consciously include active living and healthy eating in their busy lives," Olson said. Researchers said that there may be other factors besides eating out that may have resulted in higher risk factor scores, noting that the study is retrospective and self-reported information.