A new study published in the Journal of Attention Disorders has found that individuals with childhood attention-deficit/hyperactivity disorder are more likely to consume fast food frequently in early adulthood. However, no significant link was found between childhood ADHD and physical inactivity as these individuals moved from adolescence into adulthood.
Attention-deficit/hyperactivity disorder is one of the most common developmental conditions diagnosed in children in the United States. It is marked by symptoms such as inattention, impulsivity, and hyperactivity. While much research has examined the immediate challenges ADHD poses during childhood, including difficulties in school and social relationships, fewer studies have investigated how the condition might influence long-term health behaviors. The current study aimed to explore whether children with ADHD are more likely to develop habits linked to chronic health conditions—namely, poor diet and physical inactivity—as they grow older.
The researchers drew on data from the National Longitudinal Study of Adolescent to Adult Health, a large national study that tracked a representative group of adolescents in the United States over several years. The sample included 6,814 individuals who participated in three waves of the study, beginning in early adolescence and continuing into early adulthood. Childhood ADHD symptoms were measured retrospectively when participants reached early adulthood, based on self-reports about their behavior between the ages of 5 and 12. Fast-food consumption and physical activity were measured during adolescence and again in early adulthood using standardized survey items.
To measure fast-food consumption, participants reported how often they ate at popular fast-food chains over the past week. High fast-food consumption was defined as eating at such places at least three times per week in adolescence and four times per week in early adulthood. Physical activity was assessed by asking participants how many times they engaged in moderate to vigorous physical activity—like sports or exercise—during the previous week. A cut-off was applied to classify participants as physically inactive based on national health guidelines.
After adjusting for potential confounding variables such as age, sex, race, family income, obesity, depression, and neighborhood characteristics, the researchers found that childhood ADHD was significantly associated with increased fast-food consumption in early adulthood. Specifically, individuals with a history of ADHD were 49% more likely to report high fast-food intake compared to those without ADHD. This association was not found during adolescence, suggesting that the effect of ADHD on diet may become more apparent as young people gain independence and control over their food choices.
Interestingly, the researchers found no significant relationship between childhood ADHD and physical inactivity during either adolescence or early adulthood. Although previous studies had suggested that children with ADHD might be less physically active, particularly those on stimulant medications, this longitudinal analysis did not support that idea.
The findings offer insight into how ADHD may influence long-term health behaviors. One possible explanation for the higher fast-food consumption is that individuals with ADHD often seek immediate rewards and may have difficulty delaying gratification. Fast food, being quick and convenient, may cater to this tendency. Additionally, the transition to adulthood often brings new demands—like jobs, parenting, or education—that may increase stress and time constraints, making fast food a more appealing option. If these individuals grew up in households where fast food was already common, those habits may persist into adulthood.
The lack of a link between ADHD and physical inactivity in this study is somewhat surprising, especially given that prior research has suggested a connection. The authors note several possible reasons for the discrepancy. For one, earlier studies were often cross-sectional and relied on parent reports of children’s behavior, which may not be as accurate as self-reports used in this study. Additionally, many prior studies did not follow participants into adulthood, where patterns of physical activity may change. It’s also possible that children with ADHD engage in physical activity differently, or that other factors like medication side effects or family routines play a role that wasn’t captured here.
There are several limitations to the study. Since ADHD symptoms were reported retrospectively in adulthood, participants may not have accurately remembered their childhood behaviors. Self-reports of fast-food consumption and physical activity are also subject to bias, as people may overestimate healthy behaviors or underreport unhealthy ones. The researchers also lacked data on medication use during childhood and adolescence, which could influence both activity levels and eating habits.
Despite these limitations, the study adds to a growing body of research that highlights the long-term health risks associated with ADHD. It suggests that dietary habits, rather than exercise patterns, may be a key area to target in efforts to support children with ADHD as they grow into adulthood. The authors propose that cognitive-behavioral interventions could help individuals with ADHD better understand and regulate their food choices. In addition, schools and healthcare providers may play an important role by offering targeted education and support to encourage healthier eating in this population.
Future research could build on these findings by exploring how parental behaviors, medication use, and environmental factors influence dietary habits in children with ADHD. Studies using objective measures of activity, like fitness trackers, and more detailed dietary assessments could also provide a clearer picture of how these patterns develop over time.
The study, “Associations Between Childhood ADHD and Lifestyle Risk Factors for Chronic Diseases From Adolescence to Early Adulthood,” was authored by Yueqi Li, Hong Xian, Lauren D. Arnold, and Jen Jen Chang.
