dietary carbohydrate content in indian diabetic patients

Diet has always played a major role in the management of diabetes. In the pre-insulin era diet played a dominant role in the management of diabetes. Even after the discovery of insulin and several oral hypoglycemic agents diet forms the sheet anchor of treatment. The dietary approaches have varied from time to time. The pendulum has swing from the starvation diets of Allen, to restriction of carbohydrates with liberal fat, to the modern high carbohydrate and high fiber diets. The current concepts of dietary management of diabetes are based on the need to achieve glycamic control as well as to normalize the dyslipidemia which is commonly associated with diabetes. Such an approach aims at preventing the micro and macrovascular complication of diabetes. The amount of carbohydrate in the diet, the type of fat and quantity and type of protein has been altered to meet these needs. Carbohydrate content of the diet has to provide 50-60% of the calories and most of this is to be in the form of complex carbohydrates with a high fiber content and low glycemic index. Fat content of the diet should be 20-25% of the total calories distributed in the ratio of 1:1:1 among saturated fatty acids, MUFA and PUFA. PUFA content of <10% of the total calories and an EFA content of at least 3% of the total calories is advisable with the n-6/n-3 ratio being <10. Protein intake of 0.8mg/kg is recommended, so as to contribute to 12-20% of the calories. Vegetable proteins are preferable due to their high fiber content and absence of saturated fat which is present in animal proteins. Diet continues to be the sheet anchor of diabetes management and newer concepts are bound to come in future, based on experiences with current approaches and newer studies. Diet has always played a major role in the management of diabetes. In the pre-insulin era diet played a dominant role in the management of diabetes. Even after the discovery of insulin and several oral hypoglycemic agents diet forms the sheet anchor of treatment. The dietary approaches have varied from time to time. The pendulum has swung from the starvation diets of Allen, to restriction of carbohydrates with liberal fat, to the modern high carbohydrate and high fiber diets. The current concepts of dietary management of diabetes are based on the need to achieve glycemic control as well as to normalize the dyslipidemia which is commonly associated with diabetes. Such an approach aims at preventing the micro and macrovascular complication of diabetes. The amount of carbohydrate in the diet, the type of fat and quantity and type of protein have been altered to meet these needs. Both diet and exercise have been shown to improve the risk factors associated with macrovascular disease by improving the lipid profile, decreasing blood pressure and decreasing the body weight. Thus the role of dietary modifications should be emphasized to the patient. In the last three decades a lot of changes have occurred in the concepts of dietary management of diabetes. The exact nature of the diet most appropriate for diabetic individuals remains a source of 5 : 2 Medicine Update 2012  Vol. 22 236 controversy. The several issues involved are: i. The composition of the diet ii. Metabolic effects of high carbohydrate and low fat diets iii. The types of fats and carbohydrates iv. The role of fiber – its type and quantity v. The use of food substitutes Atherosclerosis is accelerated in diabetics and is a major cause of macrovascular disease resulting in an increased incidence of coronary artery disease, strokes and peripheral vascular diseases. The risk for CVD is 2-3 times greater in diabetics compared to non-diabetics. Hence a major concern of dietary therapy is metabolic normalization and reduction of cardiovascular risk factors. So the current focus is on the fat content and the type of fat, the fiber content and the carbohydrate content of the diet. The proportion of saturated fats MUFA and PUFA in the cooking oil has drawn attention. The fish oils and eicosanoids are being used to lower the atherogenic lipids. The role of micronutrients and antioxidants has also gained importance and the diet planning has to incorporate these. The objective of dietary therapy is to provide a nutritious and balanced diet. In type 1 diabetes patients the total energy input has to be increased to ensure weight recovery and growth while in Type 2 diabetes patients the calories need to be restricted to decrease the weight and foods which promote vascular complications have to be avoided. Obesity is not a major problem in our Type 2 diabetes patients compared to the west. Only about 30% of our Type 2 diabetes have a BMI >27. Majority of our patients have a BMI in the normal range). A subset of about 18-20% of our patients is underweight with a BMI of less than 19they are labeled as the “lean Type 2 diabetes”. However some of these normal weight or lean type 2 diabetes have a waist hip ratio of >0.9 and they are labeled as the “lean obese”. In prescribing a diet to a diabetic patient the following points have to be considered the type of diabetes type 1 diabetes or type 2 diabetes the weight of the individual in comparison to the ideal body weight, his occupation, activities, and the presence of any complication. In type 2 diabetes patients the first step would be dietary therapy along with exercise. About 50% of Type 2 diabetes patient achieve good glycemic control within 4 – 6 weeks. Proper patient education helps in better compliance and adherence to the diet over prolonged periods of time. Total caloric requirement is assessed based on the ideal body weight of the patient and his activity level. The prescribed diet should contain 30Kcal/Kg of ideal body weight per day. (Ideal body weight = height in cms-100). In an underweight individual the diet should provide 35kcal/kg/day while in an obese individual calories should be reduced by 5 -10 kcal/kg/ day. Additional allowances are required in case of pregnancy, lactation and for growing children. Total calories thus calculated should be evenly distributed into three principal meals and two snacks. These calories are derived from three principal sources – carbohydrates, proteins and fats. Each fraction has its own importance and should provide calories in proper proportion. 60% of the calories are to be provided by carbohydrates, 20% by proteins and the remaining 20% by fats. CARBohydRATeS Carbohydrates (CHO) constitute a major proportion of human diet. CHO rich food items are easily digested, relatively inexpensive, provide ready energy and sense of filling. These are also considered more suitable for the sick and at the extremes of age. For several decades it has been appreciated that all carbohydrate containing food items do not raise blood glucose to a similar extent within the same period of time. Ingestion of simple sugars raises plasma glucose faster and higher than food consisting of complex CHO such as starch. Even among starchy food distinction has been made between refined raw rice and potato on one hand and whole mill wheat flour and pulses on the other. Quantification of these differences has been possible following introduction of procedures for estimate of glycemic index (GI) by Jenkins et al (1981). GlyCemiC index (Gi): GI is meant to measure the change in blood glucose following the ingestion of food containing a specific amount of CHO and compare it with a reference standard such as glucose or white bread. GI is ratio between the increase in blood glucose over the fasting levels observed for 2-hour,following ingestion of a set amount of carbohydrate (50g) in the test food and the response to glucose or white bread containing similar amount of carbohydrate in the same individual. The increments are calculated from the measurement of area under the curve (AUC) in the graph drawn as in glucose tolerance test GI = ACU following the test meal/AUC after 50g of glucose or equivalent amount of white bread x 100. GlyCemiC loAd (Gl): The overall blood glucose response is determined not only by the GI value of a food but also by the amount of carbohydrate in the food. Thus the concept of glycemic load (GL) has been developed. The product of Glycemic index and value of its carbohydrate content is the glycemic load. This represents both the quantity and quality of carbohydrate consumed. Food prepared from whole grains products as whole meal wheat (flour), oats, Jowar, Rai and Ragi have low glycemic index. In addition these are rich in fiber, antioxidants and