If you wanted to lower your blood sugar and insulin, what would you do? Eat less sugar and starch? Sounds logical. That would mean you'd be getting more of your calories from protein and fat, since you wouldn't be getting as many of them from carbohydrates.
The interesting thing is that "Fish, beef, chicken, and eggs had larger insulin responses per gram than did many of the foods consisting predominantly of carbohydrate."1. I was surprised when I read about this in the FanaticCook blog, written by an actual nutritionist. In later posts, she dug up more references to studies done on how eating fat affects insulin levels. Turns out, a high-carbohydrate diet was better for insulin levels than a high-fat diet.2 And, as the FanaticCook pointed out, a low-fat vegan diet was better than the AHA-recommended diet for the blood glucose and blood lipids in a 100-patient study.3
The Atkins diet has also been shown to improve blood glucose compared to the average American diet. But studies indicate that the "good carb" diet might do an even better job.2 It would be interesting to see the comparison in a long-term study.
1. An insulin index of foods:the insulin demand generated by 1000-kJ portions of common foods. Holt, et al. Am J Clin Nutr 1997;66:1264-76
2. Effects of isoenergetic high-carbohydrate compared with high-fat diets on human cholesterol synthesis and expression of key regulatory genes of cholesterol metabolism. Vidon et al. American Journal of Clinical Nutrition, Vol. 73, No. 5, 878-884, May 2001; High saturated fat and low starch and fibre are associated with hyperinsulinaemia in a non-diabetic population: the San Luis Valley Diabetes Study. Marshall et al. Diabetologia. 1997 Apr;40(4):430-8; Dietary Fat and Meat Intake in Relation to Risk of Type 2 Diabetes in Men. van Dam et al. Diabetes Care 25:417-424, 2002
3. A Low-Fat Vegan Diet Improves Glycemic Control and Cardiovascular Risk Factors in a Randomized Clinical Trial in Individuals With Type 2 Diabetes. Barnard et al. Diabetes Care 29:1777-1783, 2006