In the same day I got both of these headlines more than once in my Facebook newsfeed:
1. New Study Lends More Weight To ‘Fat But Fit’ Theory – http://huff.to/1bRFmZ1
Researchers at Middle Tennessee State University, led by exercise scientist Vaughn Barry, Ph.D., examined 10 past studies that recorded information about participants’ body mass indexes and fitness levels. The studies looked at the weight and fitness levels of thousands of participants (the largest one included 21,856 people) and continued to follow up with the participants over several years, ranging from an average of 7.7 years to an average of 16 years.
Barry’s team crunched the numbers on those past studies by dividing participants into three weight categories based on BMI: normal weight, overweight and obese. Then they put them into two categories based on their performance on an endurance test (in most studies, this involved running on a treadmill): fit and unfit.
They found that fitness levels, not weight, predicted whether or not a participant had died in the study’s intervening years. Unfit people, regardless of their weight, had twice the risk of dying during the study than fit people, and overweight and obese people who were fit had similar mortality risks as fit, normal weight participants. Another way of putting it: thin, unfit people had twice the mortality risk as obese fit people.
The study was recently published in the journal Progress in Cardiovascular Diseases
2. ‘Healthy and overweight’ is a myth, study suggests http://m.bbc.co.uk/news/health-25118857
Excess fat still carries health risks even when cholesterol, blood pressure and sugar levels are normal, according to a study of more than 60,000 people.
It has been argued that being overweight does not necessarily imply health risks if individuals remain healthy in other ways.
The research, published in Annals of Internal Medicine, contradicts this idea.
The study looked at findings from more than 1,000 published studies.
Researchers from the Mount Sinai Hospital, Toronto, found there was no healthy pattern of increased weight when heart health was monitored for more than 10 years.
They argue that people who are metabolically healthy but overweight probably have underlying risk factors that worsen over time.
Study leader Dr Ravi Retnakaran told BBC News: “This really casts doubt on the existence of healthy obesity.
“This data is suggesting that both patients who are obese who are metabolically unhealthy and patients who are obese who are metabolically healthy are both at increased risk of death from cardiovascular disease, such that benign obesity may indeed be a myth.”
From a certain perspective the stories could both be right and not contradict one another. It might be that fat and fit people have health risks but are still better off than the unfit and thin. It might be that weight matters but that fitness matters more.
But having both these stories in my newsfeed on the same day being offered up by friends on different sides of the great weight debates made my head hurt.
Excuse me while I go watch some comfort TV, Once Upon a Time, and cheer on the Evil Regals. Yes, I know it’s not the best TV out there but I watch with resident teenagers and it’s got some kick ass women as both villains and heroes. Love the women in that show, even Snow for all that she annoys me.
You’ve highlighted the fundamental problem with epidemiological studies in general: when studying lifestyle issues (e.g., diet, level of physical activity) it’s impossible to control for all the variables so that only the data under consideration are significant. Both the studies you mention are meta-analyses, so the constituent study designs are likely to have been very varied in themselves. How much scrutiny did these study designs receive before allowing them into the meta-analysis, so that all the study design were identical? Epidemiological studies often include self-reporting in the form of questionnaires, a notoriously unreliable way of gathering objective information. And probably worst of all, these studies confuse correlation with causation; hence, weight gets interpreted as a cause of either fitness and unfitness, rather than properly being viewed as one metric among many that might influence fitness.
Being “overweight” and/or “fit” are part of a complex constellation of habits and choices that varies from person to person. Definitively factoring out everything but the “overweight” or “fit” part is sleight of hand, not science.
whoops….should be “weight gets interpreted as a cause of either fitness or unfitness…”
First, thank you for commenting on that confusion between the two studies.
Second, and more important to me at this given moment, my Once Upon a Time fangirl is squeeing over the fact that you mentioned the show, and the badass women. And especially that you posted a photo of Regina. Evil Regals Unite!!! ♥
🙂
What if cholesterol was the body’s repair mechanism? What if elevated levels of cholesterol (measured as it is carried through the bodies on the backs of proteins–either of the low- or high-density variety) was a signal that our body is attempting to repair itself?
LOVE Once Upon a Time (in spite of my cynical self).
Dr. Arya Sharma, who does research on obesity has some interesting criticism of that second study–in short, they included people with metabolic issues in:
“As shown in Table 1 of the study, 9 of the 12 studies defined “healthy” as not having the metabolic syndrome (either based on ATP III or IDF criteria), while the remaining studies defined “healthy” as having less than 2 metabolic risk factors.
As readers will perhaps recall, the ATP III defnition of “metabolic syndrome” actually requires the presence of at least 3 of 5 of the components of the metabolic syndrome, while the IDF definition actually requires abdominal obesity AND at least two other risk factors.”
His research:
“In the Edmonton Obesity Staging System healthy is defined as the absence of medical, mental or functional risk factors or limitations related to excess weight. According to this rather “stringent” definition, our analysis of NHANES and other data sets, showed virtually no increased risk associated with increased BMI or waist circumference over as long as 200 months.
In contrast, in our analyses, obese individuals with even just one metabolic (or other risk factor) were considered to have EOSS Stage 1 or 2 had clearly elevated risk.”
Here’s his blog post:
http://www.drsharma.ca/new-meta-analysis-adds-to-meta-confusion-about-healthy-obesity.html
Thanks. Very helpful.
Here’s another analysis of this study.
http://healthyurbankitchen.com/blog/obesity-how-the-media-misleads-you/
Thanks