URBANA, Ill. — Nearly half of the home-packed lunches that children brought to school each day rarely or never included vegetables, a University of Illinois researcher found in a new study of families in California.

However, the number of vegetables in kids’ lunches increased if they participated in deciding what foods to pack, said Carolyn Sutter, a postdoctoral research associate with the U. of I.’s Family Resiliency Center and the lead author of the study.

“When the child was more involved in deciding what to pack, their lunches contained more fruits and vegetables across the week and additional servings of vegetables on Mondays,” Sutter said. “Having the child help decide what they’ll eat for lunch may allow the parent and child to work together to choose fruits and vegetables the child is interested in eating.”

Even when vegetables were included in children’s lunchboxes or bags, they usually constituted just one-third to one-half of the recommended half-cup serving, the researchers found.

The children and their parents were significantly better at incorporating fruits, however, packing them in the child’s lunch nearly every day and providing about a full half-cup serving each time. About one-third of the families packed a fruit in the child’s lunch every day.

The study was based on 90 parent-child pairs from three elementary schools in California. All of the students, who were in the fourth, fifth and sixth grades, took home-packed lunches to school each day during the study. Prior to the lunch period at each school, the researchers met with each child individually, unpacked their lunch and recorded the contents.

The parents also completed surveys that assessed the potential influence of several factors in the home environment, including the child’s involvement in deciding what to bring in their lunch, the parents’ nutritional knowledge and use of authoritative parenting behaviors, and financial stress within the family that might constrain parents’ ability to provide nutritious food.

Children whose parents scored higher on authoritative parenting practices – such as showing warmth and involvement and being responsive to their child’s needs – brought greater numbers of vegetables servings in their lunches throughout the week, except on Mondays.

“Parenting practices that provide structure and support the child’s growing autonomy in dietary behavior have been found to be the most beneficial for promoting healthy habit development,” Sutter said. “These parents may create guidelines and limits around what their child can pack in their lunch, such as requiring them to include a vegetable some days, but also be responsive to their child’s needs and dietary preferences.”

When parents had greater knowledge of nutrition, their children’s lunches included more fruit servings the entire week and more servings of vegetables on Mondays. However, the number of vegetable servings declined across the week, the researchers found.

While having greater awareness of nutritional guidelines may encourage parents to pack a healthy lunch for their children at the beginning of the week, it may not be enough to buffer against conflicting factors throughout the week, such as work stress and budgetary constraints, the researchers wrote.

“Families that had financial stressors were more likely to never pack a vegetable during the week and packed fewer servings on Monday, perhaps because they don’t have access to healthy food available at home,” Sutter said.

Financial constraints may prompt parents to use their limited resources to provide fruits and vegetables at shared family meals rather than packing them in one child’s lunch, especially if the parents suspect the child won’t eat them, the researchers hypothesized.

“Providing these parents with nutrition education and suggestions on affordable vegetable options that can be easily packed in lunches or prepared to make them more appealing to the child might help increase the number of vegetable servings children consume across the week,” Sutter said. “In addition, it may be helpful to encourage families to use the National School Lunch Program some days or all of the week as a more affordable, healthy option to increase children’s consumption of vegetables.”

The study, which has been accepted for publication in the journal Appetite, was co-written by human development and family studies professor Adrienne Nishina, Cooperative Extension specialist Lenna L. Ontai, and postdoctoral research associate Jennifer C. Taylor, all of the University of California, Davis.