Physiologically, an increase in carbohydrate intake results in an increased insulin response to carbohydrates, which through its fat-storage promoting action increases obesity. And, it has been shown, that accumulation of fat inside the belly (visceral fat) is associated with chronic inflammation that is directly related to type 2 diabetes and heart attacks.
The problem is equally bad for people who already have type 2 diabetes. We know today that increasing the carbohydrate load in the diabetes diet increases what is called glucose toxicity and consequently increases insulin resistance, triglycerides level and reduces beneficial HDL-cholesterol.
The widely recognized food pyramid may now be falling out of favor
At the turn of the twentieth century (way before the USDA recommendations represented by the food pyramid) what we now know as type 2 diabetes was predominantly defined as a carbohydrate intolerance disease and was mainly treated by reducing carbohydrates intake. Carbohydrates restriction was particularly successful in treating diabetes before the discovery of insulin. Drs. Elliot P. Joslin and Fredrick Allen, the fathers of diabetes science, successfully treated their patients diagnosed with fatty diabetes (later known as type 2 diabetes) with a diet very low in carbohydrates. Today, Elliott Joslin’s diet would be considered eccentric, as seen by the reaction in the medical community to its reincarnation as the Atkins Diet.
Such extreme reduction of carbohydrates, despite being very successful in treating type 2 diabetes before insulin discovery, was in fact shown to be associated with some uncomfortable side effects, like constipation, headache, bad breath and muscle cramps. But, although the recommended amount of carbohydrates intake was significantly relaxed after the discovery of insulin in 1922, it never exceeded 40% of the daily caloric intake, an amount that was shown to reduce blood glucose and triglycerides. Thus, it was absurd that when the USDA recommendations were published several medical societies recommended increasing carbohydrates and decreasing fat intake for patients with diabetes.
Since 2003, many clinical trials have confirmed that reducing carbohydrates is still superior to reducing fat in decreasing body weight and improving glucose control. It has also been shown that reducing carbohydrates for patients with type 2 diabetes improves their sensitivity to their own insulin; reduces belly fat and triglycerides; and increases good cholesterol (HDL-cholesterol).
Recently an analysis of several studies (meta-analysis) showed that reducing carbohydrates load (amount) and glycemic index (the effect of particular carbohydrates-containing food on blood glucose) was associated with reduced risk of developing type 2 diabetes. After weight reduction, maintaining a diet that lowers the consumption of high glycemic-index foods and is higher in protein was shown to better maintain weight loss for longer duration than any other dietary composition.
The Joslin Guidelines
Since 2005, the Joslin Clinic has been recommending a reduction of carbohydrate intake to 40-45% of the total daily calories and avoidance of food that rank high on the glycemic index of carbohydrates (see glycemic index table). Joslin’s 2005 guidelines for overweight and obese patients with type 2 diabetes or those at risk to develop type 2 diabetes, which were revised in 2011, continue to recommend reducing carbohydrates intake to prevent and treat patients with type 2 diabetes and weight problems.
Recently, most medical societies departed from the recommendation of high carbohydrates intake and recommended individualization of the nutrition needs. At Joslin we have clinical proof that this is the right decision. Since 2005 we have been following the Joslin Guidelines in our weight management program (Why WAIT). The 44 groups of type 2 patients who have gone through the Why WAIT program and follow the Joslin Guidelines have lost a total of 10,000 lbs., have improved their diabetes control and cut their medications significantly.http://blog.joslin.org/wp-content/uploads/2013/08/o_hemdy-6-200x300.jpg
