The myth of the "Freshman 15"

It's nearly back-to-school time. For many recent high-school graduates, the next week or two represent the beginning of a whole new chapter: post-secondary education. Of all the challenges college freshmen need to contend with, worrying about potential weight gain should be the least of their worries. Unfortunately, due to a pervasive myth that has been too often repeated, weight gain may be on the minds of many undergraduate students.

It is a commonly held assertion that the average freshman will gain approximately 15lbs during the 2 semesters of 1st year university or college.

However, my experience and the results of numerous studies suggest that the phenomenon is purely myth, and a student who gains 15 lbs during their 1st year is clearly an exception rather than the rule.

The average university school year is approximately 30 weeks. Thus, to gain 15lbs over the 30 weeks of 2 semesters would require an additional 1750 kcals per week – which is almost an extra days worth of calories added every week. That is impressive chronic overeating.

During my first year of university, I definitely did not experience a substantial increase in body weight. If anything, the initial stress of being away from home, the foreign environment, the increased academic workload, being forced to eat cafeteria food instead of my mother's delicious cooking actually caused me to drop a few pounds. By second semester I was well adjusted, had figured out the 'healthier' eating options on campus, and had re-acquainted myself with regular exercise. When I went home for the summer, I had actually arrived in better shape (and approximately 5 pounds lighter) than when I first departed.

But that's just my isolated experience.

What does the research suggest?

Back in 2006 Morrow and colleagues published a study in the journal Obesity investigating the notion of a freshman 15. This study has one of the largest samples to look at the phenomenon of freshman weight gain, and is the only one (to my knowledge) to assess body composition. In that study, 137 female freshmen at the University of Oklahoma were assessed for body weight and composition at the start of the school year and again at the end of the spring semester.

While the study did find a statistically significant increase in body weight from the start to the end of 1st year, the average weight gain was approximately 2lbs – a far cry from the commonly touted gain of 15 lbs. And of those 2 lbs, about 25% was due to an increase in muscle.

What's also obvious when examining the results of this study is that about a quarter of the students actually lost weight during the 1st year, and many maintained their baseline weight.

So while I may be in the minority of those who lose weight in 1st year, it appears to be an experience shared by a quarter of first year students.

More importantly, the freshman 15 is more accurately the freshman 2 – but that doesn't sound nearly as exciting or catchy.

Regardless of the magnitude of weight change, the transition from home to living on your own is a critical period for developing your own dietary and activity patterns, and thus educating 1st year students on proper nutrition and regular exercise is of utmost importance.

Given the appropriate education, first year students can not only resist weight-gain, they can actually improve on the lifestyle habits they had adopted from their parents over the past 17-18 years.

That is, if your parents didn't have the best lifestyle habits, moving away from home may be an excellent chance to fix the dietary and physical activity patterns that were handed down to you from your folks.

Of course, I knew students who adopted a regular diet of beer, pizza, burgers and video games during university – these individuals fared less well with their weight and health . But this is far from the norm as often popularized by the freshmen 15 myth.

Debunking the myth that all freshmen gain weight may help remove the excuse to eat unhealthy and become sedentary – we often allow suggestion to affect our behaviour more than we'd like to think. If it is expected that most students will gain an average of 15lbs, the incoming students may feel that how their body will look in 8 months it is out of their control.

So to all incoming first-year students: Don't buy into the hype and fear-mongering. You are more likely to be a freshman 0 than a freshman 15.

This story is republished courtesy of PLOS Blogs: blogs.plos.org.