Teenagers and young adults who go to sleep late are more likely to experience weight gain, according to a new study. The said research suggests that even if teens and young people are just watching TV or hanging around, as long as they are staying late at night, it will result to heavier weights.

The study was conducted by examining the pattern of teenagers for the last 21 years through the data from National Longitudinal Study of Adolescent Health. Psych Central claims that over 3,300 youths and adults were considered as samples by the researchers coming from the University of California, Berkeley.

The research was divided into three time periods - the adolescent stage, college years, and early adulthood. The BMI and sleep patterns of the subjects were recorded together with research's major takeaway that the person who sleep early stays thin and healthy.

The result shows that for every extra hour that a person stays awake, a resulting 2.1 points of the BMI is established. Based on the subjects, gradual weight gain then followed which occurred in a five year period.

Centers for Disease Control and Prevention defined Body Mass Index (BMI) as a person's weight in kilograms divided by the square of heights in meters. The BMI of a healthy adult ranges from 18.5 to 24.9.

Lauren Asarnow, the author of the research elaborated the gathered results of the study.

"This is the first study of its kind to look at the relationship between bed times and weight gain, above and beyond the sleep duration. So, you're more likely to gain weight going to bed at 2 a.m. then you are at 9 p.m., regardless of how much sleep you're getting," said by the doctoral student of Berkeley's Golden Sleep and Mood Research Clinic.

The study however, does not conclude that all teenagers who sleep late are all destined to gain weight at their adult stage. Just like what Asarnow said, the result is just an association between bedtime and weight gain.