The less reasonable answer is that he's a unique snowflake and diet+exercise does not work for him.
I don't think "unique snowflake" is a good description. Most people who attempt diet+exercise don't lose weight.
All people who create a calorie deficit via diet and exercise lose weight.
The most recent post in December's Stupid Questions article is from the 11th.
I suppose as the article's been pushed further down the list of new articles, it's had less exposure, so here's another one for the rest of December.
Plus I have a few questions, so I'll get it kicked off.
It was said in the last one, and it's good advice, I think:
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.