Researchers tested a new method called digital photography-assisted weighing (DPAW) to measure how much food students actually eat at school lunch in Saskatoon, Canada. Instead of just guessing, they took photos and weighed leftover food to see what kids consumed. The study asked the research assistants who did this work what they thought about the method. Most said it was doable in schools, even though it took extra effort. This matters because schools want to understand if their lunch programs are actually feeding kids well, and this new method could help them find out.

The Quick Take

  • What they studied: Can schools use a new photo-and-weighing method to accurately measure how much food students eat at lunch?
  • Who participated: 11 research assistants and supervisors who worked on a school lunch study in Saskatoon elementary schools during 2021 and 2023
  • Key finding: Most research assistants (the majority) said the photo-and-weighing method could work in schools, even though it requires more work than traditional methods
  • What it means for you: Schools may be able to use this method to better understand if their lunch programs are actually feeding kids the right amounts of food. However, schools would need better training and planning to make it work smoothly.

The Research Details

Researchers interviewed 11 people who had directly used the digital photography-assisted weighing method in real schools. These weren’t experiments on kids—instead, the researchers asked the adults who did the work to share their experiences through 30-45 minute video interviews. The team asked open-ended questions to understand what worked well and what was challenging. They then looked for common themes in what people said, using both pre-planned categories and new patterns that emerged from the interviews.

This approach is called qualitative research, which focuses on understanding people’s experiences and opinions rather than collecting numbers. The researchers used a careful system to organize and analyze what people said, making sure they captured the real-world challenges and successes of using this method in schools.

Before spending money and time on a new method, schools need to know if it’s actually practical. By asking the people who did the work, researchers got honest feedback about real challenges—like training needs and coordination with school staff. This helps determine if the method can actually be used in busy school environments, not just in perfect laboratory conditions.

This study has some important limitations to understand: Only 11 out of 16 people invited actually participated, so we’re missing some perspectives. The study relied on people remembering their experiences, which can sometimes be inaccurate. The interviews happened after the work was done, so people might have forgotten details. However, the researchers used a systematic approach to organize and analyze the information, which makes their findings more reliable.

What the Results Show

Most research assistants said they would recommend using the digital photography-assisted weighing method to other researchers doing similar school studies. This is important because it suggests the method is feasible—meaning it can actually be done in real schools with real students.

However, the assistants identified specific areas for improvement. They wanted better training before starting the work, clearer instructions on how to do the process correctly, and better coordination with school staff. Some assistants found the work more time-consuming than expected, which is important for schools to know when planning their budgets.

Despite these challenges, the overall message was positive: the method works, but schools need to prepare better. The assistants felt that with improvements to training and planning, this method could become a standard way for schools to measure what students actually eat.

The research also revealed that communication between the research team and school staff was crucial. When schools understood what the researchers were doing and why, the process went more smoothly. Additionally, having clear, consistent procedures helped research assistants do their work more efficiently. The study suggests that schools need to see this as a team effort, not just something researchers do on their own.

This is one of the first studies to test whether this photo-and-weighing method can actually work in real school settings. Previous research suggested it might be too time-consuming and complicated for schools to use. This study challenges that assumption by showing that people who actually did the work think it’s possible, though it needs some refinements. The findings support moving forward with this method while making the improvements that assistants recommended.

The study only included 11 people’s perspectives, so we don’t have feedback from everyone who was invited. The interviews happened after the work was completed, so people might not remember all the details accurately. The study was done in Saskatoon schools specifically, so results might be different in other regions or countries with different school systems. The study didn’t measure whether the method actually gives accurate food consumption data—it only asked if people thought it was practical to use.

The Bottom Line

Schools interested in measuring student food consumption may consider using digital photography-assisted weighing, but should plan for: (1) comprehensive training for staff who will do the work, (2) clear coordination with school administration and lunch staff, and (3) realistic time budgets. This recommendation has moderate confidence because it’s based on staff experiences rather than direct measurement of the method’s accuracy.

School nutrition directors, public health officials, and researchers studying school lunch programs should pay attention to this. Parents might care because it could help schools improve lunch programs. Students probably won’t notice a difference, but better measurement could lead to better meals. This method is most relevant for schools in Canada or similar settings, though the general approach might work elsewhere.

If schools implement this method, they should expect to see useful data within one school year. However, improvements to the process (better training, clearer procedures) would likely take 1-2 years to fully develop and test.

Want to Apply This Research?

  • If you’re a school administrator, track the time required to conduct plate waste audits weekly, noting how many students were measured and how long training took. This helps identify efficiency improvements over time.
  • Schools could start by conducting plate waste audits once per month using this method, then gradually increase frequency as staff become more comfortable. This allows time to refine procedures and identify what works best in your specific school environment.
  • Establish a simple feedback system where staff who conduct the audits share challenges and successes monthly. Track which foods have the most waste and which are eaten completely. Use this data to adjust menu planning and portion sizes over the school year.

This study describes research assistants’ experiences with a measurement method—it does not provide medical advice or nutritional guidance for individual students. Parents and schools should consult with registered dietitians or nutrition professionals before making changes to school meal programs. The findings are based on staff perspectives in Canadian schools and may not apply to all school settings. This research does not evaluate whether the method accurately measures food consumption; it only assesses whether the method is practical to use in schools.