Department of Medicine - Surgery - University of Minnesota

Division of Endocrinology and DiabetesOver the past several years, our research group has taken a systematic,comprehensive approach to determining the effects on body function(hormonal and non-hormonal) of varying the amounts and types ofproteins, carbohydrates, and fats in the diet. We have been particularlyinterested in the dietary management of type 2 diabetes.Type II diabetes is characterized by an impaired ability to secrete insulin,even though insulin-secreting cells are still present. This results in dysfunctionalregulation of macronutrient metabolism and a rise in blood glucoseconcentration, which in turn results in the medical complications known tooccur in people with diabetes. Thus, the major goal in diabetes is to reducethe blood glucose to as close to normal as possible and to maintain theglucose at this level. Typically this is done by using drugs and/or insulininjections. One of our goals has been to develop a diet based upon soundbiological principles, which can stimulate insulin secretion and correctthe elevated blood glucose concentration in people with type 2 diabeteswithout the need for pills or insulin injections. This empowers patients tocontrol blood glucose on their own.Drs Nuttall and Gannon review research data.Research Highlight: frank Q. nuttall, M.D.DDietary fats, carbohydrates and proteins are referred toas macronutrients, in contrast to the micronutrients, i.e.vitamins and minerals. The macronutrients provide fuel for the bodyand provide building materials for growth and for replacement of worn outbody parts. They also are important for keeping the body in a high state ofhealth under differing environmental conditions. The latter is accomplishedby interacting with signaling systems that control and integrate the variousbody functions. Mechanistically, macronutrients stimulate secretionof hormones, have direct effects on regulatory pathways, or do so throughtheir digestion products in the intestines or from absorption of the digestionproducts into the blood stream. Overall, this is a very complex processthat is necessary for maintenance of life in a very uncertain world.In this regard, we have determined that dietary proteins strongly stimulateinsulin secretion and actually result in a decrease in blood glucose in shortterm studies. Some proteins are more potent than others. We also havedetermined that, in general, it is only glucose available in foods that raisesthe blood glucose.By modest changes in the diet incorporating these principles, we havedesigned diets that nearly completely correct the abnormal blood insulinand glucose values in people with type 2 diabetes within 5 weeks. Theseresults have been obtained without weight loss. Other potentially salutaryeffects of such diets have been identified. Longer term and more detailedstudies are now in progress.Confirmation of our preliminary results could significantly alter the managementof type 2 diabetes. Theoretically, dietary modification, even withoutweight loss, also could greatly delay or even prevent the appearanceof new diabetes in persons at risk for the disease.