Normal and Therapeutic Nutrition

Normal and Therapeutic Nutrition 3(2+1)

Lesson 30:Diabetes – Dietary management

Glycemic index

Ranking of the foods as per post prandial blood glucose response compared to reference diet.

Factors which influence the glycemic index

• The presence of nonabsorbable oligosaccharides and viscous dietary fibre such as pectins, ?-glucans and gum fruits, vegetables and cereals reduce the efficiency of enzyme hydrolysis and slows down the rate at which glucose enters the blood stream.
• Starch is encased in its seed coat or coarsely ground is not efficiently hydrolysed to glucose because digestive enzymes are prevented from reaching the starch.
• Starch granules subjected to moist heat and subsequent cooling become dense and less available to enzyme action. Retrograded starch has low glycemic index.
• Rice bran, which is rich in fibre and oil has low glycemic index.
• High amylose rice varieties which are slowly digested are potentially useful in low glycemic diets.
• Chapathis, which need chewing have lower glycemic index compared to wheat 'kanjee'.
• Raw food has lower glycemic index than cooked food.
• Foods rich in fat and protein have low glycemic index.
• Phytic acid present in whole grains decrease glycemic index.
• Natural food has low glycemic index compared to processed foods.
• The glycemic index for fructose is low (23) compared to lactose (46), sucrose (65) or glucose (97). Fructose produces lower risk of blood sugar than glucose. In view of its effect on serum lipid, it can be taken only in moderation.