A healthy diet can do a lot for children, but how can we make sure that they eat enough fruit and vegetables. There has been a lot of research on this topic and a whole nudging industry, but maybe one factor is easier to take into account: time. In this crossover trial of 241 lunch observations from 38 children, 20 minutes of seated lunch time were associated with significantly more consumption and significantly less waste of fruits and vegetables compared with 10 minutes of seated lunch time. Also interesting: “Entree and beverage consumption was not significantly different between the 10-minute and 20-minute seated lunch conditions.”
From the press release:
When kids sit down to eat lunch at school, fruits and vegetables may not be their first choice. But with more time at the lunch table, they are more likely to pick up those healthy foods. If we want to improve children’s nutrition and health, ensuring longer school lunch breaks can help achieve those goals, according to research from the University of Illinois.
“Ten minutes of seated lunch time or less is quite common. Scheduled lunch time may be longer, but students have to wait in line to get their food. And sometimes lunch periods are shared with recess. This means the amount of time children actually have to eat their meals is much less than the scheduled time,” says Melissa Pflugh Prescott, assistant professor in the Department of Food Science and Human Nutrition at U of I.
Prescott and study co-authors Xanna Burg, Jessica Metcalfe, and Brenna Ellison compared fruit and vegetable consumption during 10 and 20 minutes of seated lunch time, and the results were clear.
“During shorter lunch periods, children ate significantly less of the fruit and vegetable parts of their meal, while there was no significant difference in the amount of beverages or entrees they consumed. It makes sense that you might eat the part of the meal you look forward to first, and if there’s enough time left you might go towards the other parts. But if there’s not enough time those items suffer, and they tend to be fruits and vegetables,” Prescott explains.
This particularly impacts children from low-income families who participate in the National School Lunch Program and who may not have resources to bring their own lunch from home to avoid lunch line wait times, she adds.
Prescott and her colleagues conducted the study with elementary- and middle school-aged children enrolled in a summer camp on the University of Illinois campus. The researchers set up the lunch area as a school cafeteria where students would go through the lunch line and select their food. They prepared the meals according to National School Lunch Program guidelines.
“We tried to make this as comparable to everyday school as possible. We worked with the local school district and used the same food distributors as they did, and we selected the menu items based on the local public school menu,” Prescott explains.
Each day was randomly assigned to be either a short or a long lunch day. Each short lunch day was paired with a long lunch day featuring an identical menu. The researchers wanted to rule out that food types served would create any differences in what the children ate.
Research assistants took a picture of each tray as the children exited the lunch line. They monitored the time from the children sat down until they were done eating, and observed behavior throughout the meal, including any food sharing, interaction with peers, and phone use.
After the lunch period was over, the children placed their tray with any leftovers on a rack and filled out a two-question survey about the taste and appearance of their meal. The researchers measured all servings before and after the meal to obtain an estimate of how much each child ate.
While fruits were consumed at an overall higher rate than vegetables, consumption of both food types was significantly higher for longer seated lunch times, Prescott says.
She notes the study has implications for the effectiveness of the Healthy Hunger-Free Kids Act, which the U.S. government implemented in 2010 to improve nutrition standards for school meals.
“In my opinion, one of the best things about the new nutrition standards is that they require a variety of vegetables be served each week, to ensure children from all income and resource levels get exposed to different healthy foods they might not have access to at home. But if we have lunch periods that are too short to allow children the opportunity to get used to those foods, then we’re almost setting the policies up to fail,” Prescott says.
“A main takeaway from our study is that children need protected time to eat their fruits and vegetables. Our findings support policies that require at least 20 minutes of seated lunch time at school,” she states.
School lunch time policies can be decided at the district level, with some room for individual schools to set their own standards; for example, schools can institute a longer lunch time than the district mandates.
Prescott notes that longer lunch times can also have beneficial effects for children beyond healthy eating.
“The amount of seated time children have is also a really valuable time for them to connect with their peers; they might have limited opportunities to do so throughout the school day. We found significantly fewer social interactions during the 10-minute lunch times. That indicates other positive outcomes may come from longer lunch breaks as well,” she concludes.
Abstract of the study:
Importance Health experts recommend at least 20 minutes of seated lunch time for children, but no federal policy for lunch period duration exists in the United States. Additional strategies in the National School Lunch Program for mitigating food waste are needed to maintain the viability of the Healthy, Hunger-Free Kids Act.
Objective To assess the effect of a longer seated lunch time on food consumption and waste among elementary and middle school–age children.
Design, Setting, and Participants This randomized within-participant crossover trial was conducted from June 3 to June 28, 2019, for a total of 20 study days. All attendees of a summer camp held at the University of Illinois at Urbana-Champaign, were invited to participate in the study. Participants were elementary and middle school–age children and were provided every study day with lunch prepared according to the National School Lunch Program nutrition standards.
Intervention Five menus were served throughout the study. A 20-minute or 10-minute seated lunch condition was randomly assigned to each day within the 5 menus.
Main Outcomes and Measures The primary outcomes were food consumption, waste, and dietary intake, which were analyzed separately for each meal component (fruit, vegetable, entree [protein plus grain], beverage [both milk and water], and milk alone). Dietary intake was assessed for calories, fat, carbohydrates, fiber, protein, vitamin D, calcium, iron, and potassium. Participant behaviors were observed during the meal, including seated time as well as level of talking and phone use.
Results A total of 38 children with 241 lunch trays were observed. The 38 children had a mean (SD) age of 11.86 (1.23) years and 23 were female participants (61%); 30 had a non-Hispanic/non-Latino ethnicity (79%) and 23 were White individuals (61%). During 10 minutes of seated lunch time, participants consumed significantly less fruit (−11.3 percentage points; 95% CI, −18.1 to −4.5) and vegetables (−14.1 percentage points; 95% CI, −22.7 to −5.7) compared with 20 minutes of seated lunch time. Entree and beverage consumption and waste did not differ between the 10-minute and 20-minute seated lunch conditions. Participants also consumed significantly more and wasted significantly less calories (−22.03 kcal; 95% CI, −39.47 to −4.61 kcal), carbohydrates (−3.81 g; 95% CI, −6.20 to −1.42 g), dietary fiber (−0.51 g; 95% CI, −0.81 to −0.19 g), protein (−1.11 g; 95% CI, −2.17 to −0.04 g), iron (−0.20 mg; 95% CI, −0.38 to −0.02 mg), and potassium (−53.49 mg; 95% CI, −84.67 to −22.32 mg) during the 20-minute seated lunch condition.
Conclusions and Relevance This study found that fruit and vegetable consumption increased in school-age children during a 20-minute seated lunch condition. This finding supports policies that require children to receive at least 20 minutes of seated lunch time; such policies could have favorable implications for children’s dietary intake and food waste.