About the Study | How Does This Affect You?

Being obese or overweight can significantly increase the risk of heart disease, diabetes, and even decrease your lifespan. When extra weight is accumulated during childhood, a child is at risk for developing diseases more commonly associated with adults, such as high blood pressure and high cholesterol. Children that are obese are also much more likely to become obese adults. Weight gain often happens as a result of lifestyle choices, such as food choices and lack of physical activity.

Researchers in Boston wanted to determine if habits common to teens were linked to an increase of body mass index (BMI). BMI is a measurement based on height and weight that helps determine ideal weight ranges and obesity. The study found that a lack of sleep, time spent on the internet, and alcohol use were linked to more gains in BMI for adolescent girls.

About the Study

The cohort study sent surveys to more than 5000 girls 14-21 years of age. The surveys asked about internet usage, sleep, and coffee (caffeinated) and alcohol consumption in the previous year (2000 to 2001). The survey also asked for height and weight measurements from the beginning and end of the year. Researchers accounted for factors that would also affect BMI, such as growth and development and activity levels. At the end of the year, habits that were associated with increases in BMIs included:

  • higher amounts of internet time
  • higher levels of alcohol intake (two or more servings per week)
  • less sleep time (five hours per night or less)

The habits were also highly associated with each other (eg, higher internet time was linked to less sleep). Drinking coffee was not linked to weight gain and was not associated with increased internet time. High levels of all of these habits led to nearly four pounds of weight gain over one year.

How Does This Affect You?

A cohort study is an observational study. This means that the study cannot establish a cause and effect relationship, it can only suggest a connection. The information was also gathered from memory recall of the participants who may over- or under-estimate sleep, alcohol, coffee, and internet time. However, other research has suggested a connection between lack of sleep and weight gain, which strengthens these findings.

Teens and young adults may need as many as nine hours of sleep per night. Developing a sleep schedule and having a comfortable environment are important steps to a good nights sleep. Set a timer on your computer to remind you to log off at least an hour before your bedtime. This will keep you from absently surfing hours into your sleep time. Try to keep a regular sleep routine, even through weekends; it will make it easier to fall asleep each night. Also keep in mind that alcohol can disrupt the quality of your sleep. Most steps of weight management require some work—take advantage of a step that only requires some sleep.