Boosting sleep and limiting screen time are key steps for unmedicated youth with ADHD, study finds

Mizzou researcher identifies health behaviors that could help unmedicated youth with attention deficit hyperactivity disorder (ADHD) — and the general public — live a healthier lifestyle.

Crystal Lim pointing at a screen.
Crystal Lim is an associate professor in the College of Health Sciences.

July 8, 2024
Contact: Brian Consiglio,
Photos by Sam O'Keefe

More than 6 million children in America have been diagnosed with attention deficit hyperactivity disorder (ADHD). Now, a new study co-led by the University of Missouri has uncovered a striking correlation: Unmedicated youth with ADHD not only have significantly higher rates of obesity, but they also tend to exceed screen time recommendations and fall short of meeting crucial sleep guidelines.

Mizzou’s Crystal Lim, an associate professor in the College of Health Sciences, and other researchers analyzed the results of a nationally representative survey that included tens of thousands of youths between the ages of 11-17. Parents of three groups — those without ADHD, those with ADHD on medication and those with ADHD not on medication — were asked how much sleep, screen time and exercise their children were getting daily.

Lim and the research team concluded that while sleeping more and limiting screen time are healthy behaviors for all children, prioritizing these two goals can be particularly helpful for unmedicated youth with ADHD, given that the group has a higher prevalence of obesity.

Crystal Lim listening to students in her lab.
Lim directs the Mizzou Health Psychology Research lab, where she mentors undergraduate students.

Lim added that while common stimulant medications to treat ADHD such as Adderall may result in a suppressed appetite as a side effect, not all ADHD medications are stimulants, and medication is only one small piece of the puzzle.

“If some families are not as interested in medication, identifying sleep as a key health behavior to target for improvement can help reduce the obesity risk,” Lim said. “As a clinical psychologist, I regularly meet with families and give them evidence-based strategies for creating long-lasting, healthy behavioral changes, including goal setting, monitoring health behavior progress, and parental role modeling.”

Killing two birds with one stone

Not only has awareness of ADHD grown in recent years, so too has the topic of pediatric obesity. Lim’s research is designed to help children with both.

As childhood obesity rates have skyrocketed in the United States since 1990 — particularly in rural and underserved areas — Lim has been on a mission to help families and schools encourage healthy lifestyle behaviors for children of all ages. In 2022, Lim published a study examining childhood obesity prevention programs in rural schools with the ultimate goal of emphasizing the importance of both nutrition and exercise as opposed to just one or the other.

After working in an obesity clinic in Mississippi — a state where 40% of adults were obese in 2021 — Lim was attracted to Mizzou because of the interdisciplinary collaboration opportunities within the College of Health Sciences and with other departments and schools at Mizzou.

“Getting to collaborate with psychologists, medical providers, therapists and researchers at Mizzou has been great because my work is at the intersection of all of it,” Lim said. “I am currently involved in projects related to mobile applications for helping youth improve their health behaviors, and being in an environment with interdisciplinary collaboration has been exciting.”

Going forward, Lim hopes her research can encourage children and families to incorporate healthy behaviors into their daily lives.

“My goal is to offer strategies for how we can modify our evidence-based treatments as clinical psychologists in practical ways to help children and families as best that we can,” Lim said. “Seeing how passionate families are about helping their children has been very rewarding to me, so I want to help as many people as possible.”

Summer suggestions

With summer having arrived, Lim offers the following tips to all families considering how the end of the school year might impact their child’s routines regarding sleep, screen time and exercise:

1. Set a nighttime routine for consistently going to bed at the same time.

2. Consider cutting off internet access at a certain time.

3. Avoid having TVs or other screens in bedrooms.

4. Avoid large meals right before bed.

5. Encourage physical activity during the day through activities such as swimming, sports or summer camps.

6. Create a cool, dark environment to promote sleep.

7. Use screen time as a reward after chores, educational activities, or physical activities are completed.


“Understanding health behaviors that modify the risk for obesity in ADHD,” was published in the Journal of Pediatric Psychology.

Editor's note

Lim collaborated on the study with Delanie Roberts from the Children’s Hospital of Los Angeles, Dustin Sarver and Benjamin Walker from the University of Mississippi Medical Center, and Annah Cash from Virginia Polytechnic Institute and State University.

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