Consciousness 153APA Goal 2: Scientific Inquiry
and Critical Thinking
Weight Gain and Sleep
Addresses APA Learning Objective 2.1: Use scientific reasoning
to interpret psychological phenomena.
Many people have heard that it’s common for young people going off to college or
university for the first time to gain weight. There’s even a name for it, the “freshman
15.” Some of the reasons people have given for this weight gain, citing “commonsense”
reasoning, include being away from home (and parental supervision) for the first time,
more partying than studying, and mass consumption of junk food, among others. But
common sense, as we’ve seen, doesn’t always give an accurate picture of what is
really happening. For accuracy, we need to determine what science says about the
freshman 15.
First we need to ask, do first-year college students really put on weight their first year
of school? The answer seems to be yes, but not quite as much as rumor has it. The actual
freshman weight gain tends to be about 3.5 to 6 pounds (Holm-Denoma et al., 2008;
Roane et al., 2015). Score one for science, not so much for common sense.
Now that we know there is a weight gain, what could be the cause or causes of that
gain? We do know that college students probably don’t get the amount of sleep recom-
mended by experts, which is a little over 9 hours a night (Dahl & Lewin, 2002; Hirshkowitz
et al., 2015). Sleep deprivation can make you eat more, and there’s evidence that when
teens and young adults are sleep deprived, they tend to go for sweet foods that are high in
calories and low in nutrition (Simon et al., 2015).
But is it the fewer hours of sleep or the timing of the amount of sleep freshman do
get? Students often get to bed much later when away at school than when at home, and
one study has shown that for every hour bedtime was pushed back, there was a gain of
about two points in body mass index or BMI, an indicator of how much body fat a person
has (Asarnow et al., 2015).
A more recent study suggests that in addition to all of these factors, the weight
gain experienced by many freshman college students may also be a result of irregular
sleep patterns: Not only do students get less sleep and go to bed later, but they also go
to sleep at different times due to different class schedules and social activities. While a
person who is working has a schedule of getting up at a certain time and going to bed
by a certain time on a regular basis, students may get to bed at midnight and get up
at 7 A.M. one night but go to bed at 2 A.M. the following night and get up at 9 A.M. Even
though both nights are 7 hours of sleep, the shift in the schedule is what may cause
more sleep deprivation symptoms, according to a study conducted by researchers at
Brown University in Providence, Rhode Island (Roane et al., 2015). When your sleep–
wake cycle is shifted daily by 2 to nearly 3 hours, it’s like having daily jet lag—just like
shift workers and frequent flyers.
So the “freshman fifteen” is real, but more like the “freshman five,” and the causative
factors are not as simple as common sense might tell us. The sleep deprivation symptoms
brought on by not only less sleep but also frequent variability in sleep cycles lead to fatigue
(which leads to less exercise) and eating more sweets for quick energy boosts, eventually
leading to weight gain. In the Brown study, this weight gain amounted to about 6 pounds
in only 9 weeks!