Widely available in public schools, vending machines are contributing to bad eating habits and poor nutrition among young students and their presence in schools undermines the school’s job of teaching good nutrition, according to a group of US researchers. The food items most often sold in vending machines are not surprising: soft drinks, chips, and sweets.

Schools are introducing foods that every nutritional scientist in the world knows are dangerous.

More nutritious offerings from vending machines are part of a bill passed December 2nd by the House of Representatives. The bill upgrades the fare for federally subsidized school meals and makes it easier for tens of thousands of poor kids to get free meals as well as providing stronger controls on the types of foods dispensed by school vending machines. Because the Senate had already passed the Healthy, Hunger-Free Kids Act unanimously months ago, the bill is now on its way to President Obama for his signature.

Researchers from the National Institutes of Health surveyed nearly 6,000 students in 152 schools to study the impact of vending machines on children’s food choices. Eighty-three percent of the schools surveyed sold foods with little nutritional value in vending machines. Soft drinks were the most common item sold.

In lower grades the availability of fruits and vegetables in vending machines resulted in students eating more produce than students in schools that didn’t offer healthy foods. Similarly, students who went to schools where vending machines were stocked with sweets ate more sweets. Elementary schools were less likely to have vending machines than higher grades.

The presence of vending machines did not seem to affect food consumption among the students in higher grades, perhaps because junk foods is available in other settings such as school stores, snack bars, and a’ la carte sales or because teens have greater access to foods outside school such as purchases from convenience stores or fast food restaurants. Either way, vending machine foods contributed less to their daily energy intake compared to younger children.

In a Center for Advancing Health news release, co-author of the study, Ronal Iannotti, of the U.S. National Institute of Child Health and Human Development said, "Schools provide not only an environment for learning but an environment that affects healthful eating and physical activity. Schools policies should require the establishment of an optimum environment for child health."

Dr. Joel Fuhrman, a nutrition researcher specializing in preventing and reversing disease added, "We are supposed to be teaching proper nutrition in the schools, and having a vending machine inside of the school doesn’t make sense. Schools are introducing foods that every nutritional scientist in the world knows are dangerous."

The study was published online in November 2010 in the Journal of Adolescent Health.

Food and beverages sold at schools outside the National School Lunch Program or the School Breakfast Program are considered "competitive foods." They are no federal nutrition guidelines for these foods and they are often referred to as Foods of Minimal Nutritional Value (FMNV). FMNV are described as "those that provide low amounts per portion of specified nutrients."

Many studies have looked at the impact of competitive foods from vending machines (and other sources) on the dietary health of school children. Nationwide, 97% of schools have high calorie competitive foods, such as sweetened beverages, chips, and candy, accessible to students.

In a study published earlier this year, researchers found that 18 percent of middle school students reported purchasing food from a vending machine instead of buying school lunch. Even though healthier items were available, students mainly purchased chips, pretzels, crackers, candy bars, soft drinks, and sports drinks. A 2009 study determined that 40% of children consumed one or more competitive foods, usually a high-calorie, low-nutrient food or beverage, during a typical school day. Children who ate school lunch were less likely to purchase competitive foods than children who did not eat school lunch.

The third School Nutrition Dietary Assessment Study looked at the consumption of competitive foods and beverages, excluding a’ la carte items, among 2,300 school children in grades one through twelve. Twenty-two percent of students consumed a competitive food during the school day with intake being highest among high school students. The students who ate competitive foods had higher intakes of energy and sugar, and lower intakes of sodium, fiber, B vitamins, and iron than those who did not eat competitive foods.

These studies point to the need for schools to develop policies that reduce the availability of unhealthy items in vending machines, as well as other school venues, and improve school food environments and policies. The intake of competitive food and beverages at school has proven to be detrimental to the overall quality of children’s diets.

The Child Nutrition and WIC Authorization Act of 2004 required that all school districts that take part in the federally funded school meals program to develop and implement school wellness policies that address nutrition and physical activity by the beginning of the 2006-2007 school year. Schools were left to determine those policies and decide how to implement them. The new bill should change that.

In August of this year, the American Dietetic Association published an update to its position paper on local support for nutrition integrity in schools. The position paper suggests the following indicators of nutrition integrity in regard to vending machines:

  • The availability of competitive foods complies with federal regulations and the local wellness policy
  • Extra items offered for sale consider the students’ needs for calories and nutrients and support what students learn about nutrition and health
  • Standards are established for portion sizes and nutritional content of food items sold individually.