Ghrelin, a gut hormone that stimulates appetite, is associated with improved insulin sensitivity. As the subjects lost weight, those with the best insulin sensitivity had the greatest increases in ghrelin.
The study did not look at appetite. Ghrelin increases appetite, but lower insulin levels decrease appetite. Perhaps it is a wash in the end.
A 5 week, moderate carbohydrate, high fat diet produced better results than a higher carbohydrate diet in diabetics. The subjects also retained more nitrogen, suggesting lean muscle gain.
Add fatty liver disease to the list of diseases associated with the metabolic sydrome (aka syndrome x).
Note that those with higher levels of intrahepatic fat (IHF) had lower levels of fat oxidation while fasting and less insulin sensitivity. High insulin levels basically shut down fat oxidation altogether, these subjects remained partially in that state around the clock.
PMID: 16684857
Both polyunsaturated and monounsaturated fat improved insulin sensitivity, but only monounsaturated fat improved beta-cell insulin secretion.
The abstract does not mention the type of polyunsaturated fat used. It is my contention that omega-3 polyunsaturated fats improve insulin sensitivity, while omega-6 polyunsaturated fats decrease insulin sensitivity.