Information that surprises you is interesting as it exposes where you have been miscalibrated, and allows you to correct for that.
I suspect the users of LessWrong have fairly similar beliefs, so it is probable that information that has surprised you would surprise others here, so it would be useful for them if you shared them.
Example: In a discussion with a friend recently I realised I had massively miscalibrated on the percentage of the UK population who shared my beliefs on certain subjects, in general the population was far more conservative than I had expected.
In retrospect I was assuming my own personal experience was more representative than it was, even when attempting to correct for that.
Sex education (including non-abstinence) may not work at all, and if it does work it works only in a very weak and limited way.
Eating cholesterol doesn't cause high blood cholesterol. Eating saturated fat probably doesn't cause higher blood cholesterol. High blood cholesterol levels are protective against cancer and the mortality gain here probably outweighs any mortality loss from cardiovascular disease. The entire science of cholesterol is confused and terrible and practically every statement you have ever heard that includes the word "cholesterol" is very likely a lie. (link to a readable blog post with some of this, but you can also find it all in big-name medical journals)
The (good!) effect of drinking alcohol on life expectancy is super strong. Drinking wine a few times a week is correlated with up to four years gain in lifespan (effect mostly found in the middle-aged, might not be such a good idea in young), and people who are smart and understand that correlation isn't always causation have amassed some decent evidence that at least some of this might be causal.
Labeling the amount of calories in food (for example on McDonald's restaurant menus) totally fails to change people's eating behaviors at all, no matter how hard people study it. Article here, credit to SarahC for pointing this out to me.
I hate all of these facts and wish they were not true, which makes me a credible source for them.
I'm a fifth year med student from Finland, a long time lurker, and you provoked me to post the first time. Thank you for that, I'm a terrible procrastinator. I'm a also big fan of many of your submissions. The alcohol fact seems right and the other two I can't comment on, so I'll focus on cholesterol. In this case I'm surprised of seeing no criticism.
If the information you present about cholesterol is true, I am highly surprised too, and I hope you're right because otherwise the information is potentially very deadly. The effect, whatever the direction, is... (read more)