Monday, October 22, 2018

Fast Initial Weight Loss The Secret To Success? Or Do Only Successful People Remain In Weight Loss Studies?

There was a lot of buzz last week about a new study that purportedly found that "fast initial weight loss may be key to diabetes prevention".

I say purportedly because the reporting wasn't about a published study, but rather a presentation given to the European Association for the Study of Diabetes (EASD) 2018 Annual Meeting on the to be published one day PREVIEW study.

The presentation reported that 3 years after an initial rapid, induced by meal replacement, weight loss, by way of 4 different dietary strategies, 96% had not developed type 2 diabetes.

This was contrasted apparently with the results of the Finnish Diabetes Prevention Study (DPS) and US-based Diabetes Prevention Program (DPP), neither of which included that initial rapid 2 month meal replacement loss, and where participants without diabetes at 3 years in the DPS and DPP were 91% and 86%, respectively.

So yes, the PREVIEW results were a touch better.

Or were they?

Whereas the DPS and DPP studies had tremendous retention of participants (92% and 92.5% respectively), PREVIEW's results come from just 41% of initial participants with 59% being lost to follow up at 3 years.

Which leads me to wonder whether PREVIEW's results are worthy of much publicity, as that's a tremendous loss to follow up, and it's quite plausible that the people most likely to follow up 3 years later, are the ones who did the best in sustaining their losses. I suspect therefore, that even here, success is dependent simply on adherence, and not on weight loss modality.

Finally, as always, I'll point out, that there is no one best way, and reporting like this, whether on a study with incredibly poor retention or otherwise, suggests to the public and to health care professionals that there may be one right or best way, despite the fact that different strategies will work differently for different people, which I would argue in turn, undermines patient care.