I've watched several videos and also read his blog He's a medical Dr. so he knows biochemistry inside out.
A few years ago he found he was developing Metabolic Syndrome, often a precursor to T2. He was gaining weight despite being an athlete and eating the standard healthy athletic diet (high carb, high protein, low fat). His solution was to cut carbs drastically and raise his fat intake. He lost 40 lbs. and his symptoms of metabolic syndrome disappeared.
His latest project is the Nutritional Science Initiative which aims to fill in the holes in our knowledge of nutrition and get to the bottom of the current obesity/diabetes epidemic.
Here's a video previously shared by Judith, in an earlier post, that touches on the issues you raised, Hanna.
http://www.ted.com/talks/peter_attia_what_if_we_re_wrong_about_diabetes.html