An anecdote about anecdotal evidence [View All]

[DanTex]

As we all know, anecdotes do not constitute scientific evidence. Nevertheless...

Some 10-15 years ago, Atkins and other low-carb diets were going through a fad phase. I saw people go on Atkins and lose tons of weight. But the official story was that it was dangerous, your cholesterol would spike from all the fat you were eating, and any weight you lost would be water and it would come right back when you went off.

I went on Atkins. I lost some 30 pounds rather quickly (about 3 months). My blood tests got better. After I went off, I did not just gain the weight right back.

As a scientific person with scientific friends, I would often encounter people who insisted that you only lose water weight on Atkins and that it was dangerous. And I was like, I understand that there are not many studies backing me, but there's no way in hell that I lost 30 pounds of water. I remember thinking, I wish people would just try cutting out carbs for three weeks, and then come back and tell me about how it doesn't work. I couldn't tell you the biological mechanism, but it was clear that, for me at least, low carb resulted in remarkable weight loss with relatively little effort or hunger.

Fast forward.

In the 2000s, studies starting coming out confirming what I "already knew". For example,
http://www.annals.org/content/140/10/778.abstract
http://www.annals.org/content/140/10/769.abstract


So, does this prove anything? I guess not really.

But it has affected the way I treat personal experience and the dreaded "anecdotal evidence". After all, here we have a situation where my personal experience ran in direct contradiction to what was widely believed at the time. Rationally, my own anecdotal evidence was no match for the medical establishment. And yet, ten years later, it turns out that "my own lying eyes" were right the whole time.

So now, It's not that I take anecdotes to be scientific evidence, just that I don't dismiss them offhand, especially if the person involved is me or someone I know closely and trust. I try to keep an open mind: maybe there's something going on here that hasn't been fully explored yet in clinical studies. In the case of low-carb diets, it turns out there just weren't many/any big studies done comparing low-carb to conventional low-fat diets done until the 2000s. The anti-low-carb arguments were based not on direct evidence, but on the implications of generally accepted theories of nutrition and metabolism.