Insulin dosage depends on eating pattern: medical expert

Islamabad: Individuals requiring mealtime insulin need to accurately count carbohydrates as part of their meal planning. However, it is not just carbohydrate-containing foods and beverages that affect postprandial glucose levels. Carbs, when consumed in combination with protein and fat, will affect glucose response and change how much insulin a patient should be taking.

Consultant Nutritionist and Head of Department of Clinical Nutrition at Shifa International Hospital, Dr. Rezzan Khan shared useful insights on the effects of the food we eat on the management of diabetes.

Talking exclusively with ‘The News’ here on Saturday, Dr. Rezzan said, “Proteins have a different effect when consumed with or without carbohydrate.” For example, purely protein meals e.g., lean steak with salad may require a different insulin dosing strategy than when protein-rich meals are combined with fat and carbohydrate. “Increasing protein quantity in the meal decreases glucose excursions (highs and/or lows) within 1 hour after the meal and then increases glucose excursions 2 to 5 hours after the meal. On the other hand, fat delays gastric emptying; therefore, a high-fat meal requires more insulin,” she shared.

When a meal is both high in fat and protein, more insulin is required than lower-fat/protein meals with identical carbohydrate content. Dr. Rezzan said, higher-fat meals like pizza or typical Pakistani gravy is eaten with roti or rice, may affect blood glucose levels after six hours. “For such meals, splitting the insulin into two injections: one before the meal and another 1 to 2 hours later can be suitable for people on multiple daily insulin injections. Observe the results. Early post-meal hypoglycaemia means too much insulin upfront, and you should shift more insulin to the second injection. Blood glucose above target 6 to 7 hours post-meal means the insulin injection size was too small, and you should increase the amount for next time,” she said.

According to the eminent nutritionist, the sequence of when food is eaten also matters. When carb, protein, and fat foods are eaten in the meal, the timing of when the bulk of calories are eaten throughout the day affects the glucose level. “Consume the carbohydrate portion of the meal (bread, pasta, potatoes) at the end of the meal (after the protein and non-starchy vegetables) as it lowers post-meal glucose excursions,” she guided.

Dr. Rezzan underlined the need to develop one’s self-management and trouble-shooting skills. “Keep food records and relate it with continuous glucose monitoring. This helps you to notice which meals result in blood glucose levels higher than the target. You should not shy away from ‘trial and error’ as everyone’s response to a particular meal is different. This practice will help you to learn which meal you should eat less often, change some of the ingredients or change the amount of some of the foods,” she recommended.

Carb counting accuracy is very important. “Patients should understand how the insulin works with the eating style. Education is best given by a team approach and should not simply be delivered by giving a person a one-size-fits-all diet sheet. Two otherwise identical persons can have different glucose reactions to the same food, and thus you should learn what works for you,” she concluded.

There is an immense need for dietitians to promote educational programmes among doctors, healthcare professionals, and patients regarding mealtime insulin dosage. Insulin injections are a form of medical intervention and need to be carefully administered and monitored to ensure they are beneficial.