As I pointed out in a recent post, when you identify and address the cause of weight gain – weight gain stops, and that’s usually it!
That many of us fail to recognize this rather simple principle, is again illustrated by a paper by Penner and colleagues published in the Journal of Joint and Bone Surgery, which found that successful ankle reconstruction surgery does not decrease BMI in overweight and obese patients.
According to their findings, the 145 patients with excess weight who underwent successful ankle replacement or ankle fusion, despite significant improvements in Ankle Osteoarthritis Scale (AOS) scores and increased physical activity scores, pretty much maintained their preoperative BMI levels at six months and one, two, and five years.
Based on these findings, the authors conclude that:
“Pain and disability are significantly reduced in overweight and obese patients after successful ankle replacement or fusion. Despite this, the mean BMI remains unchanged after the surgery, indicating that weight loss does not commonly occur following successful ankle reconstruction in this patient population. Obesity is likely attributable to factors other than limited mobility caused by ankle arthritis.”
Obviously, the authors assumed that if limited mobility caused weight gain, then increasing mobility should reduce it – that, however, is not what happens.
Rather, what they found, is exactly what I would expect – with regain of their mobility, patients stopped gaining weight – and that’s all.
Without a targeted obesity treatment strategy, there is indeed no reason to expect that these patients would now begin losing weight simply because their activity levels may now be somewhat higher than before. The few extra calories that they may perhaps now burn as a result of being more physically active would easily be compensated by an increased intake or other biological mechanisms that are there to ‘defend’ their current weight.
Thus, the observation that successful ankle surgery did not result in ‘spontaneous’ weight loss neither disproves nor proves that pain or disability may have contributed to weight gain in the first place – it probably did in some and probably did not in others.
Interestingly enough, I believe that this study also bears an important lesson for those attempting to address obesity at a societal level – even if we did know what exactly is driving the obesity epidemic – removing this cause does not necessarily mean everyone gets thinner – it just means that things may hopefully not get worse.
Penner MJ, Pakzad H, Younger A, & Wing KJ (2012). Mean BMI of Overweight and Obese Patients Does Not Decrease After Successful Ankle Reconstruction. The Journal of bone and joint surgery. American volume, 94 (9) PMID: 22552679