What cannabis use really tells us about university students’ eating habits

Cannabis has a reputation for making people hungry. Popular culture has long joked about the “munchies,” and many people assume that students who use cannabis naturally have poorer diets than those who don’t.

Our latest research suggests the story is more complicated.

As researchers who study the health behaviours of university students, we surveyed more than 1,500 students at a large Canadian university to better understand the relationship between cannabis use and diet quality. At first glance, the findings appeared to support what many people might expect. Students who had used cannabis in the previous month reported slightly poorer overall diet quality than students who had not.

But that relationship changed when we looked at the bigger picture.

Rather than being explained by cannabis use alone, differences in diet quality were largely accounted for by broader lifestyle behaviours, particularly meal skipping. This finding reminds us that health behaviours rarely occur in isolation. They tend to cluster together, making it difficult to identify a single behaviour as the cause of another.

Understanding these patterns matters because simple explanations can sometimes lead us to the wrong conclusions.

Looking beyond a single behaviour

University life is a period of tremendous change. Many students are living independently for the first time, balancing classes, work, social commitments and financial pressures while trying to establish routines that support their health.

Healthy eating often becomes one of the first habits to suffer.

Students commonly skip breakfast before an early lecture, grab fast food between classes or eat irregularly because of busy schedules. These same students may also sleep less, spend more time sitting, consume more energy drinks or use substances such as alcohol or cannabis. None of these behaviours necessarily occurs on its own.

Researchers have long recognized that health behaviours tend to cluster. People who engage in one health-related behaviour are often more likely to engage in others, whether those behaviours are beneficial or harmful.

This makes studying health much more challenging than it first appears.

Imagine trying to determine whether carrying an umbrella causes people to get wet. People carrying umbrellas are certainly more likely to be wet, but the umbrella is not the reason. Rain is influencing both.

Health research often faces similar challenges. Two behaviours may occur together without one directly causing the other.

What we found

In our study, approximately one in three students reported using cannabis during the previous month.

Initially, cannabis users had lower diet quality scores than non-users. That difference remained after accounting for demographic characteristics, physical activity, sedentary behaviour, sleep, mental health and living arrangements.

However, once skipping meals was considered, the association was no longer statistically significant.

This doesn’t mean cannabis has no relationship with diet. Nor does it mean meal skipping causes poorer diet quality among cannabis users.

Instead, it suggests that meal skipping and other lifestyle behaviours may help explain why cannabis users appeared to have poorer diets in the first place. Looking only at cannabis risks overlooking the broader pattern of behaviours that shape student eating habits.

Why this matters

Cannabis use often receives significant public attention, particularly since legalization in Canada. Discussions frequently focus on cannabis as though it exists independently from the rest of a person’s lifestyle.

Our findings suggest that this approach may oversimplify a much more complex reality.

Students who use cannabis may also experience irregular schedules, higher energy drink consumption or other behaviours that influence diet quality. Focusing on one behaviour while ignoring the others may limit the effectiveness of health promotion efforts.

For universities, health-care providers and policymakers, this means that interventions encouraging regular meal routines, adequate sleep, physical activity and other healthy daily habits may have broader benefits than approaches that focus on a single behaviour in isolation.

A reminder about interpreting research

Our study was cross-sectional, meaning we collected information at one point in time. Because of this, we cannot determine whether cannabis use influences diet quality, whether dietary habits influence cannabis use or whether both are shaped by other factors.

This distinction is important because headlines often imply cause and effect when research can only demonstrate an association.

Scientific research rarely produces simple answers. Instead, it helps us better understand the many factors that influence health and how those factors interact with one another.

When it comes to university students, diet quality appears to be influenced by far more than whether someone uses cannabis. It reflects a broader collection of everyday habits and routines that develop during one of the most important transitions of young adulthood.

Improving student health may therefore begin not by focusing on one behaviour, but by helping students build healthier routines that support many aspects of their lives.