Glucose Effects from Different Meals
| Author: Janine Freeman, RD,LD,CDE |
| Last Updated: Wednesday, April 16, 2008 |
Q: “I have type 1 diabetes and have noticed that my blood sugars stay high for a long time after eating certain foods like Italian food and pizza. Do you have any suggestions to help me keep my blood sugar in control when eating these foods? When is the best time to test my blood sugar after eating a meal?”
A: Monitoring your blood glucose before and after meals allows you to get an idea of the differences in how your body responds to various types of meals. Although there are a number of factors that affect your glucose levels after meals, the amount of carbohydrate in your meal has the most effect. The more carbohydrate-containing foods you eat at a meal, the greater the rise in glucose after your meal unless you adjust your insulin to cover the additional carbohydrate. Studies have also shown that different types of carbohydrate affect glucose levels differently.
Fat affects glucose absorption
Glucose from high-fat meals is absorbed more slowly resulting in a delay in the rise in glucose after the meal. Your glucose levels will remain higher longer before returning to your pre-meal level after a high-fat meal.
- For example, your glucose levels after a meal that includes chicken, vegetables, and a roll will generally return to your premeal glucose level within approximately 2-3 hours of eating the meal.
- Whereas, you may observe that a meal of spaghetti and meat balls that contains the same amount of carbohydrate causes your glucose to remain high approximately 4-5 hours after this high-fat meal.
Monitor the effects
- Monitoring your blood glucose with a meter and strips (fingersticks) will allow you to see your blood glucose level at the time you check. The more often you check your blood glucose, the more information you will get. Many healthcare professionals suggest that you check your blood glucose before your meal and 2-hours after the start of the meal at a minimum. You may want to check every hour until your blood glucose has returned to your premeal glucose level to help you determine how long your glucose remains elevated after the meal.
- Continuous glucose monitoring (CGM) is a relatively new technology that provides a person the opportunity to see their glucose levels continuously throughout the day and night by simply looking at their CGM device. They can evaluate glucose patterns and trends on the hand-held device or retrospectively review reports and graphs in a software program. Your glucose response to various meals can be compared which can help you determine how to make adjustments in your diabetes management to help keep your glucose in your target range.
How to assess your blood glucose response
To determine your body’s glucose response to various types of meals, test your meal on several occasions and keep other variables as consistent as possible:
- Eat the same type and amount of food each of the test days, making note of the amount of carbohydrate (be sure to measure your food portions using standard measuring utensils or use the nutrition information from the package label)
- Maintain the same level of physical activity (time, amount and type)
- Keep the dosage and timing of insulin as consistent as possible
- Monitor your glucose levels frequently
- For blood glucose monitoring (fingersticks), check before the meal and 2, 3, and/or 4 hours after the start of the meal. Remember, the more often you check, the more information you will get.
- For continuous glucose monitoring, mark the time you eat, the amount of carbohydrate in the meal, and the type of meal so you can later identify your glucose tracing that corresponds with each meal.
Keep track of how your glucose responds to a particular type of meal and work with your diabetes care team to make adjustments in your diabetes management accordingly. You may decide to change the timing of your meal-time insulin injection or bolus based on your results. If you use an insulin pump, you may decide to try a combination or dual-wave bolus for a high-fat meal that results in prolonged high blood glucose. One study showed that using a dual-wave bolus over 8 hours was the most effective in controlling glucose after eating pizza.
An important point to remember is that every day with diabetes is a little different. It is impossible to predict with certainty how your glucose will respond to a particular type of meal or situation. In addition to the effect of the meal on your glucose levels, you will also need to consider your glucose level before the meal, insulin, physical activity, stress, and illness.
Conclusion:
Although there are many factors that affect how your body responds to a meal, the amount of carbohydrate has the most effect. Learning how to count carbohydrate and practicing these skills is the first step in helping you control your after-meal glucose levels. Monitoring your glucose frequently is key to helping you determine how to make adjustments in your diabetes management to accommodate these different types of meals.
References:
Freeman J and Lyons L. The use of continuous glucose monitoring to evaluate the glycemic response to food. Diabetes Spectrum 21,2008 (in press)
American Diabetes Association. Dietary carbohydrate (amount and type) in the prevention and management of diabetes. Diabetes Care 27: 2266-2271, 2004
Jones S, Quarry J, Caldwell-McMillan M, Mauger D, Gabbay R. Optimal insulin pump dosing and postprandial glycemia following a pizza meal using continuous glucose monitoring system. Diabetes Technol Therapeut 7:233-239, 2005
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Important Notice: The responses provided by the team of Diabetes Educators are based on their personal experiences and expertise as practicing diabetes healthcare professionals, and are not to be considered diabetes management advice from Abbott Laboratories. Remember that information provided by the team of Diabetes Educators is for general background purposes and is not intended as a substitute for medical diagnosis or treatment by a trained professional. You should always consult your physician about any healthcare questions you may have, especially before trying a new medication, diet, fitness program, or approach to healthcare issues.
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