Why do some people never get fat?
And why are some people unable to lose weight, even when they seem to be doing everything right?
We've all got that one friend who eats junk food, never exercises, yet remains slim.
And that other friend, who's always at the gym, only eats carrot sticks, but can't shake the fat.It's easy to blame genetics, or luck, or willpower, but is that the full story?
If you've always suspected there's...