Thursday, November 11, 2021

2021's Dumbest Scientifically Published Exercise Recommendation For The Treatment Of Obesity

[First written blog post since March 2020. What an awful 20 months. Though the pandemic is certainly not over yet, it feels like it's time to start writing again. Not sure what the frequency of posts will be, but it's nice to be back]
I wouldn't have believed it was real if I hadn't seen this phenomenon so many times before - a research study trying to tie their findings to the treatment of obesity despite the findings being either incapable of leading to clinically meaningful weight loss, or ridiculous to suggest in the first place. Here we've got both.
Published in Cell Reports Medicine, the paper Altered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming men looked at the brown fat stores of Scandinavian men who alternate brief outdoor winter swims with a dash to the sauna 2-3x weekly. 
What'd they find?
The non-randomly selected winter swimmers, all 8 of them, whose average BMIs were 23.7 and whose average age was 25, were found, when exposed to cold, to generate more heat from their brown adipose tissue than their 8 age and weight matched controls. 
How many calories did that brown adipose tissue heat generation burn? If we take their results at face value (their results are orders of magnitude higher than found in a prior study of albeit older subjects), they report that during a "cooling period" of 30 minutes (there was no difference during a "comfort state"), resting energy expenditure was higher in the winter swimmers by an extrapolated 484kcal/24hours. They also reported that winter swimmers spent on average 11 weekly minutes in cold water. So during those 11 minutes the winter swimmers might well be burning 3.7 more calories than their non-winter swimming counterparts - the equivalent number you'd consume eating 1/10th of a carrot. 
The paper is full of various hypotheses to try to tease out the findings from this very small study. 
But what struck me was their final conclusion, 
"Finally, our findings motivate investigations of winter swimming as a lifestyle intervention for increased energy expenditure in obese subjects as a potential weight loss strategy."
Really? Your n=8, non-randomized, observational study of young men without obesity, that didn't control for any weight related variables, which showed that during their 11 minutes of winter-swimming the swimmers might burn 3.7 more calories per week for 4 months than non swimmers motivates investigations of winter swimming as a potential weight loss strategy in people with obesity?
Photo By Jaan K√ľnnap - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=87539864