It’s no secret that our lifestyle choices dictate our physical and mental well being. And new research suggests that those choices might be especially important for young adults.
A team of University of Otago researchers – working with some international collaborators – tracked more than 2,000 young people across New Zealand, the United Kingdom, and the United States. What they found is that a handful of behaviors — fruit and vegetable intake, physical activity, and sleep quality — make up the holy trinity of our day-to-day psychological well-being. And of those three, good sleep appears to be the single most critical factor for younger adults.
“This age group faces unique pressures – such as leaving home, financial stress, educational pressures and social stressors – that can lower happiness,” senior author and Otago psychiatry professor Tamlin Conner explained. “Understanding what lifestyle factors support well-being can help young adults not just ‘get by’ but thrive during this critical life stage.”
Sleep Takes Center Stage
Young adults (between the ages of 17 and 25) typically report lower well-being than any other age group. Researchers blame crushing financial and social pressures paired with lifestyle patterns that lean toward late nights and fast food.
The study combined multiple datasets: a cross-sectional survey of more than 1,000 participants and two “daily diary” studies in which the participants tracked their sleep, activity, diet, and mood over a period of several days or even weeks. One dataset even incorporated Fitbit data to track participants’ physical activity.
What the international team of researchers found was clear, if not entirely unexpected. Young adults who slept better reported a dramatically higher sense of well-being.
And, the researchers insist that it’s about much more than rest. Poor sleep can throw off our circadian rhythms, drain our energy levels, and make it much harder to concentrate. It also hampers any positive emotions, all of which can conspire to drag down how well we function.
Diet seemed to be the second most reliable indicator – fruit and vegetable consumption in particular. Those who consumed more servings of fruits and veggies also reported higher life satisfaction and mood. The benefits appeared to peak around five to six servings a day — a little more than the survey average.
“Of these healthy habits, sleep quality stood out as the strongest and most consistent predictor of next-day well-being but eating fruit and vegetables and being active also helped boost well-being,” Conner added.
But maybe the most interesting find was the revelation that fruit and vegetable intake seemed to mitigate the effects of a bad night’s sleep. On days when participants ate more produce than usual, the drop in well-being from poor sleep was less severe.
“Across the two daily diary studies, young adults who ate more fruit and vegetables after a poor night’s sleep experienced less of a drop in well-being the next day. While poor sleep still predicted reduced well-being, healthy eating appeared to buffer some of its negative effects,” Conner explained. “This suggests that improving basic lifestyle behaviours, especially sleep, can meaningfully enhance well-being. Importantly, these changes are practical and can be made without costly interventions.”
Other Factors
Physical activity also made a difference, though less consistently at the “between-person” level (comparing one individual with another). At the “within-person” level, however, the pattern seemed to be much stronger. On days when people exercised more than usual, they felt better.
Ultra-processed foods (UPFs), on the other hand, showed no consistent relationship with well-being. In one dataset, higher intake correlated with better well-being; in another, with worse. So, while the researchers acknowledge a link between UPFs and poor physical health, their direct influence on psychological well-being might be more context-dependent.
The Bigger Picture
The study highlights that the three lifestyle habits largely acted additively. That means small improvements in any of the three areas might help, without requiring perfect scores across the board.
The results could make a huge difference in university wellness efforts and health campaigns overall.
Historically, mental health interventions focus on preventing or treating mental illness early on. But the Otago team argues that fostering positive well-being deserves equal attention. And healthy lifestyle habits might be a practical way to do that.
The researchers stress that this doesn’t mean that young adults can skip professional help if they’re struggling with anxiety or depression. But it does suggest that everyday choices about sleep, diet, and activity play a larger role than we thought in building resilience.
Further Reading
Young Adults See Smaller Gains from NHS Talking Therapies
