This post is written by Osama Hamdy, M.D., Medical Director, Obesity Clinical Program, Director of Inpatient Diabetes Management at Joslin Diabetes Center, Assistant Professor of Medicine at Harvard Medical School. Dr. Hamdy is also the Director of the Why WAIT program where he works with people to improve their diabetes management through weight loss.
Medical Nutrition Therapy (MNT) means using nutrition as a potent diabetes management tool. MNT not only plays a major role in preventing and treating diabetes but also helps in preventing many diabetes complications.
The diet composition from carbohydrates, fat and protein has been debated for a long time. Before the discovery of insulin in 1922, modified dietary composition was the only available tool to treat diabetes. At the turn of the 19th century, Fredrick Allen used a starvation technique to treat both type 1 and type 2 diabetes in his Physiatric Institute in Morris town, NJ. He was able to keep patients with type 1 diabetes alive for several years without insulin.
On the other hand Elliot Joslin in Boston gave his patients very few carbohydrates to eat. His 1,800 calorie diet had only 10 grams of carbohydrates, which made up only approximately 2 percent of the daily calories per patient with the rest coming from protein (20 percent) and fat (about 75 percent). (This diet was reincarnated later as Atkin’s diet.)
Dr. Joslin was a believer that diabetes is a carbohydrate intolerance disease and people with diabetes should reduce or eliminate carbohydrates. Interestingly, through his limited carbohydrates diet, he was successful in treating most patients with type 2 diabetes, which was called at that time fatty diabetes. He was also able to keep many patients with type 1 diabetes alive before insulin discovery.
The introduction of insulin made it possible for patients with type 1 diabetes to better utilize calories and consume diets with carbohydrates similar to those of healthy individuals. However, the ideal dietary composition has remained a debated issue.
In the first half of the 20th century, Elliot P. Joslin and others recommended a diet composed of 40 percent of caloric intake from carbohydrates, 40 percent from fat, and 20 percent from protein to all patients with diabetes. This dietary composition was widely accepted by health care professionals as the standard diabetes diet until the late 1970s when a concern was raised about the increased incidence of coronary artery disease among patients with diabetes, which was partially blamed on the excess calories from fat sources.
This concern urged the medical community to agree on reducing fat intake to around 30 percent of the total daily caloric consumption. The recommended decrease in fat intake required a compensatory increase in either carbohydrate or protein intake as percentage of total calories.
Unfortunately, the decision was made at that time to increase carbohydrate content by that 10 percent taken from fat. These changes made the “diabetes diet” to contain approximately 50 to 55 percent of its caloric content from carbohydrates, 30 to 35percent from fat, and 15 to 20 percent from protein.
We know now that this dietary plan contributed significantly to the increased prevalence of obesity and made diabetes difficult to control. Now, there is increasing evidence that a modest increase in dietary protein intake above these recommendations is a good option toward better diabetes control, weight reduction, and improvement in blood pressure and lipid profile.
Check back next week for a run-down of the modern dietary recommendations for people with diabetes.