j08 What he is saying is that he thinks that the current thinking, ie that obesity causes metabolic syndome and insulin resistance (when insulin no longer has the desired effect of converting glucose to energy), which leads to Type 2 diabetes, is wrong.
He thinks that the insulin resistance comes first. Then, because the insulin doesn't work properly, the sugar is converted to fat and the person becomes obese.
The question is what causes the insulin resistance - he thinks it is refined carbohydrates, as opposed to simply too many calories.
He thinks that medics should stop blaming and condemning patients with metabolic syndrome and Type 2 diabetes, because for years they have been given the wrong advice.
But the video is quite moving in the way that he expresses humility and remorse for having been wrong, and judging patients in the past.