There is a lot of interest swirling around the study that showed a larger thigh circumference may add years to one’s life.
To start, I want to remind everyone that the strongest predictor of your lifespan is the various lifespans of your parents, siblings, and grandparents.
To continue, I wanted to first link to the full text of the study itself. Please take a little time to read through this, take a look at the graphs, think about how the sampling changes based on what is being looked at (in other words, sometimes the author is only talking about the group of people who died during the study period, which instead of 3000 people, is closer to 300).
Another point is how the study is being marketed. A great example is this “caveat” tacked on to the end of an MSNBC article:
She was quick to add, however, that the study should not be interpreted as a free pass for people who want to skip the gym. In this case, much bigger was not better. The protective benefits of heftier thighs didn’t rise when thighs grew larger than 60 centimeters. “There’s no further advantage there,” Heitmann said.
This is the usual media/study author obesity-study-lie-by-omission (can’t give those fatties any reason not to loathe themselves, or for thinner people not to loathe the fatties). If you look at the charts in the original study, you’ll notice that though the supposed benefit is maximized at a thigh circumference of 60 cm, there is no marked decrease of benefit with larger thigh circumference. That is, at 70 cm one enjoys every bit of the benefit enjoyed at 60 cm.
However, I encourage you to come to your own conclusions about this study, based on the text itself. The text author is an out-and-out obesity researcher: his bread and butter is trying to show correlations to health indices based on weight, BMI, body fat, etc (just do a search for his name and institution on Google Scholar).