Though well-being may be a subjective concept, the researchers distinguished it as how people think and feel about their life experiences in positive ways, especially with regard to their happiness and life satisfaction.
Citing research by Stanford University psychologist Sonja Lyubomirsky, the researchers defined happiness "as an individual's subjective feelings about joy and contentment while viewing and experiencing one's life in a meaningful and worthwhile way."
Similarly, life satisfaction refers to what a person may consider a good or successful life.
The study found that a student's happiness was more important than BMI alone in predicting the students' physical and mental health.
"Happier students are more likely to participate in socially enriched events," Chen says, as well as engage in productive, healthy social interactions with others and take part in intellectually challenging activities compared to less happy students.
These students also tend to be more functional and productive in coping with normal stresses of life, the researchers note.
The study suggests that maintaining healthy body weight and fostering hopeful thoughts, thankful dispositions, life satisfaction and happiness are effective intervention strategies for promoting physical and mental health among university students.
As Chen continues studying this area of health and wellness, she hypothesizes this approach should work well for adults who have mental health problems, cancer patients and any patients with chronic disease.
But for any students seeking to make an immediate change, Chen has one recommendation: "Exercise the body and exercise the mind to strengthen both body and mind."
Like this story? Like CNBC Make It on Facebook.
What to do if you're miserable at work, according to a happiness expert
A psychology expert says spending your money on this can boost your happiness