This is the study quoted by the last article I posted about insulin
resistance and saturated fat. However, I think that the American Diabetes
Association has never found any results or correlations such as that quoted
in these papers (abstracts).

Marilyn

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Substituting dietary saturated for monounsaturated fat impairs insulin
sensitivity in healthy men and women: The KANWU Study.

Vessby B, Unsitupa M, Hermansen K, Riccardi G, Rivellese AA, Tapsell LC,
Nalsen C, Berglund L, Louheranta A, Rasmussen BM, Calvert GD, Maffetone A,
Pedersen E, Gustafsson IB, Storlien LH; KANWU Study.

Unit for Clinical Nutrition Research, Department of Public Health and Caring
Sciences/Geriatrics, University of Uppsala, Uppsala, Sweden.

AIMS/HYPOTHESIS: The amount and quality of fat in the diet could be of
importance for development of insulin resistance and related metabolic
disorders. Our aim was to determine whether a change in dietary fat quality
alone could alter insulin action in humans. METHODS: The KANWU study
included 162 healthy subjects chosen at random to receive a controlled,
isoenergetic diet for 3 months containing either a high proportion of
saturated (SAFA diet) or monounsaturated (MUFA diet) fatty acids. Within
each group there was a second assignment at random to supplements with fish
oil (3.6 g n-3 fatty acids/d) or placebo. RESULTS: Insulin sensitivity was
significantly impaired on the saturated fatty acid diet (-10%, p = 0.03) but
did not change on the monounsaturated fatty acid diet (+2%, NS) (p = 0.05
for difference between diets). Insulin secretion was not affected. The
addition of n-3 fatty acids influenced neither insulin sensitivity nor
insulin secretion. The favourable effects of substituting a monounsaturated
fatty acid diet for a saturated fatty acid diet on insulin sensitivity were
only seen at a total fat intake below median (37E%). Here, insulin
sensitivity was 12.5% lower and 8.8% higher on the saturated fatty acid diet
and monounsaturated fatty acid diet respectively (p = 0.03). Low density
lipoprotein cholesterol (LDL) increased on the saturated fatty acid diet
(+4.1%, p < 0.01) but decreased on the monounsaturated fatty acid diet
(MUFA) (-5.2, p < 0.001), whereas lipoprotein (a) [Lp(a)] increased on a
monounsaturated fatty acid diet by 12% (p < 0.001).
CONCLUSIONS/INTERPRETATION: A change of the proportions of dietary fatty
acids, decreasing saturated fatty acid and increasing monounsaturated fatty
acid, improves insulin sensitivity but has no effect on insulin secretion. A
beneficial impact of the fat quality on insulin sensitivity is not seen in
individuals with a high fat intake (> 37E%).