Avoid carbs that spike insulin, not fat

http://www.tmuscle.com/free_online_article/sports_body_training_performance_interviews/eat_your_lungs_out_while_getting_leaner

He "spent a year reporting a story on how we came to believe that low-fat
diets are good for us. Again, the science behind it was pretty
universally terrible."
...
"The answer, which we've known since the early 1960's, is insulin.
Insulin is the hormone that primarily regulates fat accumulation. If
you want to get fat out of your fat tissue, you have to lower your
insulin levels.

And insulin is regulated for all intents and purposes by the
carbohydrates in our diet. That's the simplest possible hypothesis.
The physicist would call it "the zero-order approximation."

Other hormones play roles, and most of them work to get fat out of the
fat tissue, but they can't do it if insulin levels are elevated.
Adrenaline, growth hormones, all these things work to make you leaner,
but they don't work if insulin levels are elevated.

And this has never been controversial. That's the weird thing."