Central obesity is associated with insulin resistance through factors that are not fully understood. Researchers studied the effects of three different diets on body fat distribution, insulin sensitivity and peripheral adiponectin gene expression.

Adiponectin is secreted from fat tissue into the blood. The presence of adiponectin can result in improved insulin sensitivity and glucose tolerance, and can assist in mobilizing sugar out of the blood The hormone plays a role in the suppression of the metabolic derangements that may result in type 2 diabetes, obesity, atherosclerosis and non-alcoholic fatty liver disease.

The study involved 11 volunteers who were the offspring of obese type 2 diabetic patients with noticeable abdominal fat deposits. The volunteers were considered insulin resistant and they maintained average hemoglobin A1c levels of greater than 6.5% without medication. All subjects underwent three dietary periods of 28 days each in a crossover design: a) diet enriched in saturated fat (SAT), b) diet rich in monounsaturated fat (MUFA; Mediterranean diet) and c) diet rich in carbohydrates (CHO). Weight, body composition and resting energy expenditure remained unchanged during the three dietary periods. However, when patients were fed a CHO-enriched diet their fat mass was redistributed towards their abdominal region and their periphery fat accumulation decreased compared with a diet MUFA-rich and high SAT diets. Changes in fat deposition were associated with decreased levels of adiponectin after meals and lower insulin sensitivity.

The results of this study conclude a diet rich in monounsaturated fat prevents central fat redistribution and a decrease in after meal adiponectin levels. These findings support the belief that a carbohydrate-rich diet in insulin-resistant subjects exacerbates the insulin resistance. The moral of the story is: to enhance insulin sensitivity - look for a diet rich in monounsaturated fats and less dense in carbohydrates. Chances are if you've tinkered around with your food pyramid - you already knew the results of this study.

Overeating can shut down a natural brain function that is key to preventing common cardiovascular and diabetic diseases..

Researchers found that chronic overeating can overwhelm the neural pathway that regulates the amount of fats flowing into the bloodstream from the liver. The liver is partly responsible for regulating fats entering the blood stream. It produces triglyceride fats the body can turn into LDL (bad) cholesterol, which can cause arteriosclerosis and blood vessel blockage. Glucose can enter the brain when levels are elevated in the bloodstream. When glucose enters the brain, it is broken down into an acidic substance known as lactate. Lactate signals the liver to stop making fat. It appears that chronic overeating can overwhelm the brain's ability to metabolize glucose into lactate. When lactate is no longer produced -- the signal to stop the liver from releasing fat into the blood stops, too. As small arteries get clogged, they create the circulatory problems common in type 2 diabetes, linked to overeating, obesity, and limb amputations.

Smaller portions, less glucose in the brain, better traffic flow. After all - nobody likes getting mixed signals. Let's do all we can to keep the lines of communimcation (and our arteries) open.