College Lifestyles Can Shape Weight for Decades, Tufts Study Finds

The choices students make about food, sleep and exercise before and during college can echo across decades, shaping their weight well into adulthood, a new Tufts University study suggests.

Researchers followed thousands of Tufts undergraduates from just before freshman year to as many as 20 years later and found that people who started out with the least healthy lifestyles and kept those habits gained the most weight over time. Those who maintained healthier behaviors gained the least.

The work, published in the journal Nutrients, underscores early adulthood as a pivotal period for weight gain. Nationally, almost a third of U.S. adults are overweight and 43% have obesity. Young adults ages 18 to 25 are especially vulnerable as they leave home, juggle new responsibilities and test their ability to maintain good habits on their own.

This transition makes the college years uniquely important, according to senior author Dan Hatfield, an adjunct assistant professor in the Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy at Tufts.

College is this critical window when young people have newfound autonomy and are making their own decisions around physical activity, diet, and other health behaviors more so than in earlier years,” he said in a news release. ”Setting college students on a path toward maintaining or adopting healthy behaviors may have long-term implications for health and wellbeing.”

To explore how early lifestyle patterns relate to later weight, the research team drew on data from the Tufts Longitudinal Health Study.

Between 1998 and 2007, 4,641 incoming Tufts undergraduates completed a survey before starting college. They reported how often they ate fruits, vegetables and dairy; their physical activity levels; sleep quality; and whether they followed an omnivorous, vegetarian, vegan or other dietary pattern. They also self-reported their height, weight, age, gender and other demographic details.

In 2018, 970 of those former students, now alumni, filled out a similar follow-up survey. That rare long-term connection allowed researchers to see how lifestyle behaviors changed over 11 to 20 years and how those changes related to shifts in weight and body mass index (BMI).

Using a statistical technique called latent class analysis, the team grouped students at each time point into three lifestyle patterns: healthy, moderately healthy and minimally healthy. The healthier groups tended to eat more fruits and vegetables and be more physically active.

Next, the researchers looked at how individuals moved between those patterns from precollege to adulthood. They defined five lifestyle “trajectories”: stable healthy, stable moderately healthy, stable minimally healthy, worsened and improved.

The most common path was stable moderately healthy, which described 36.7% of participants. Overall, about half of respondents maintained their precollege lifestyle into adulthood. Nearly one-third saw their habits worsen, while about 18.6% improved.

Weight status shifted over time as well. Two-thirds of participants maintained a healthy weight, one-quarter moved into a less healthy weight category, and less than 1% moved to a healthier weight category. Others remained in stable overweight or stable obesity.

The prevalence of overweight in the group more than doubled, rising from 12% to 26%. Obesity quadrupled, from 2% to 8%. Even so, the rates of overweight and obesity in this sample remained much lower than national averages, a reminder that the findings may not apply to all young adults. The researchers noted that the study only included Tufts students, who may differ from the broader U.S. population in important ways.

Still, the patterns were clear: lifestyle trajectories from the precollege years through college and into adulthood were closely tied to long-term weight outcomes. Maintaining healthier behaviors appeared to offer protection, while staying on a minimally healthy path or slipping into less healthy habits was linked with greater weight gain.

Co-author Christina Economos, the dean of the Friedman School of Nutrition Science and Policy and principal investigator of the Tufts Longitudinal Health Study, emphasized the broader importance of tracking obesity over time.

“Investigating the obesity question over time from different angles and demographics is crucial to moving the needle on a complex issue,” she said in the news release. “With each study like this, we build our own understanding of a condition that has vexed individuals and policy-makers alike. This latest research suggests college campuses may have a role to play with initiatives that promote healthy behaviors and improve weight-related health outcomes.”

That potential impact is significant. Nearly two-thirds of recent high school graduates in the United States are enrolled in college, which means campuses reach millions of young adults right as their long-term habits are taking shape.

The study points to a range of campus-level strategies that could make healthier choices the easier default. Examples include clear nutrition labeling in dining halls, a la carte and trayless dining that can nudge students toward more mindful eating, residence halls organized around health themes, sleep education programs and required physical activity courses.

Hatfield noted that institutions can help reduce the pressure on individuals to constantly make the “right” choice in environments that often promote convenience over health.

“College campuses can take some of the burden to adopt healthy choices off individuals by making those options easier and more accessible,” he said.

At the same time, the researchers stress that colleges are only part of the picture. Habits often begin forming long before move-in day, shaped by family routines, community resources and broader social and economic factors. The study acknowledges that parental influences and home environments likely play critical roles in establishing patterns that either support or undermine healthy weight management later on.

The findings add to a growing body of evidence that prevention efforts need to start early and span multiple settings, from homes and schools to colleges and workplaces. For students and families, the message is that small, consistent behaviors around food, movement and sleep in the late teen years can have lasting consequences. For colleges and policymakers, the study highlights a powerful opportunity to build environments that support those healthy trajectories rather than work against them.

The Tufts team plans to continue examining how different aspects of campus life and early adulthood experiences shape health over time. As obesity rates remain high nationwide, long-running studies like this one can help identify when and where interventions might make the biggest difference.

Source: Tufts University