I was reading studies on Pubmed that has recently changed my mind on insulin-resistance. According to numerous studies, diabetes is caused by a condition called “lipotoxicity”. I’m not going to post the numerous studies that prove this… it would be far too tedious, but I assure you the science is there.
Basically the adipose-tissue (body-fat) can only store so much dietary-fat. Insulin shuttles fat you eat into adipose-tissue and prevents adipose-tissue from releasing free-fatty-acids (it prevents fat breakdown) called lipolysis. The more fat that is stuffed into the adipose-tissue, the larger the fat-cells expand and the less sensitive they become to insulin. Eventually a point is reached where the adipose-tissue becomes resistant to the actions of insulin (due to being over stuffed with fat). When the adipose-tissue becomes insulin-resistant, insulin can no longer inhibit lipolysis.
Increased lipolysis sends free-fatty-acids into the bloodstream (causing atherosclerosis) and they accumulate thought the body causing fatty-heart, fatty-liver and fatty-muscles. The accumulation of fat on these organs inhibits the ability of insulin to promote uptake of nutrients in these tissues and they literally began to starve to death. Excess free-fatty-acids also accumulate on the pancreas and impair insulin-secretion.
Interestingly enough, studies show that fasting causes an increase in liver-fat, muscle-fat and intramyocelluar-lipid accumulation, due to decreased insulin-secretion and increased lipolysis. This also explains why moderate alcohol consumption promotes health and decreases the risk of metabolic-syndrome; alcohol is metabolized into acetate, which is a potent inhibitor of lipolysis . However too much alcohol decreases appetite, decreased appetite means less insulin-secretion, leading to increased lipolysis and therefore fatty-liver… commonly seen in alcoholics.
The solution to all of this would be to eat foods that cause insulin-secretion (to inhibit lipolysis) and foods that are naturally low in fat (to prevent adipose-tissue from being overstuffed with fat). Starches fit the bill perfectly. Fruit not so much, because most of the calories in fruit (or sugar in general) is fructose, which actually converts into fat in the liver and does not stimulate insulin-secretion. Starch is pure glucose, which does not convert into fat, and effectively stimulates insulin-secretion.
 Am J Clin Nutr. 1999 Nov;70(5):928-36. De novo lipogenesis, lipid kinetics, and whole-body lipid balances in humans after acute alcohol consumption. Siler SQ, Neese RA, Hellerstein MK.