Thursday, November 26, 2015
For some Thanksgiving blogging I started out by typing the keywords “family” and “Thanksgiving” into Web of Science. Weirdly, I got a lot of articles in Korean, one on birth rates in the Old Order Amish, and one on whole body donation in Australia. Okaaay, new search term time. Perhaps unsurprisingly, I crossed paths with nutrition research and ended up with a multitude of articles about weight gain. I mean, let’s face it, ‘tis the season for spending money and eating, which are not mutually exclusive.
A short paper published by Hull et al. in 2006 in the Nutrition Journal looked at weight changes over the Thanksgiving holiday in college students. If you are a researcher, college students are a convienient demographic to study. There are many of them, they are close, and you can incentivize them with free food. That being said, this age range (18-29) also has the fastest rising obesity rates, attributed to lower energy expenditure that result in gradual yearly weight gain. In the past, wrote about a study that addresses the myth of the Freshman 15, a study that also concludes that gradual weight gain is to blame. However, this is all annual time scales. The Hull study addresses more discrete periods of weight gain within the year. The holidays are one of those fat-inducing times of year, postulated to be the result of increased stress and caloric intake combined with decreased activity. Did I mention that I’m sitting on a couch, watching football, and blogging? Check that box, science.
The researchers recruited a bunch of college students to visit their “human body composition laboratory” prior to the Thanksgiving holiday break and asked them to return 5-7 days after the break. During each visit, demographics, body weight and measurements, and body mass index (BMI) were collected. They found a significant increase in body weight between the two visits, about 1.1 pounds (0.5 kg). This was true for the group as a whole but also when broken down by gender. However, when broken down by class standing, graduate students gained and undergrads did not. When categorized by BMI, those that were already overweight/obese (over 25 kg m-1) are the ones that increased in weight rather than those classified as normal BMI (less than 25 kg m-1). Additionally, in females, there was a correlation between baseline BMI and weight change. Oddly (at least to me), was their finding of decreases in waist circumference and waist/hip ratio – not something they really take the time to explain.
Frankly, the authors don't spend much time interpreting their own results, just listing a bunch of other studies without really relating it back to their own. But let's think about it. I mean, we’re only talking 1 pound here. Sure, that seems rather trivial, but remember to factor in time. This study followed people for a relatively short time period (5-17 days) and still saw significant change. Expand your timeline and you add evidence to the gradual weight gain argument. This study showed that this is a risky time of year, particularly for those groups already prone to overeating. The authors do conclude that their findings have important practical implications for effective intervention strategies, especially in those higher risk groups (although their use of “associated co-morbidities” seems a bit, well, morbid).
Soooo…..I think I’m going to go eat some turkey and mashed potatoes and green bean casserole and cranberry sauce and….
Hull HR, Hester CN, & Fields DA (2006). The effect of the holiday season on body weight and composition in college students. Nutrition & metabolism, 3 PMID: 17192197
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