What Factors Slow the Absorption of Carbohydrates?
When carbohydrates are quickly digested and absorbed, they can cause spikes in your blood sugar levels. While there are some misconceptions about the effects of eating high-fat or high-protein foods along with carbohydrates, eating carbohydrates with fiber or foods containing certain other components can help slow carbohydrate absorption and minimize its effects on your blood sugar levels.
Types of Carbohydrate
Sugars are the most quickly absorbed type of carbohydrate, with starches a close second since it doesn’t take very long for your body to break the bonds between the many sugar molecules that form the starch. In contrast, the third type of carbohydrate, fiber, can slow down the emptying of your stomach and the absorption of sugars and starches. This is one of the reasons why foods made with whole grains are healthier than those made with refined grains, since refined grains have been stripped of much of their fiber.
Fat and Carbohydrate Absorption
Eating foods containing fat along with those containing carbohydrate isn’t a good way to slow down carbohydrate digestion. Although fat also slows down the emptying of the stomach and the absorption of sugar into your blood, it doesn’t seem to affect the amount of insulin released after consuming carbohydrates, according to a study published in “Diabetologia” in 1984. Because of this effect, diets high in fat may increase insulin resistance, which is a precursor to diabetes. Another study, published in the "European Journal of Clinical Nutrition" in 2005, found a similar effect, with added fat increasing insulin levels while slowing gastric emptying and decreasing blood sugar.
Protein’s Potential Effects
Although diabetics are sometimes advised to eat protein-rich foods along with those containing carbohydrates, protein doesn’t actually slow the absorption of carbohydrates, according to an article published in “Diabetes Spectrum” in 2000. Different types of protein have differing effects on the absorption of carbohydrates, according to a study published in “Metabolism” in December 2012. While both fast-absorbing protein like that found in whey or soy and slower-absorbing protein like the casein in milk increased insulin levels when consumed with carbohydrates, they also decreased the effectiveness of the insulin, delaying the absorption of the sugars from the blood. Slow-absorbing protein had less of an adverse effect on insulin function, making it the better option.
Some foods, including white kidney beans, contain substances that help block the absorption of carbohydrates by limiting the effects of the enzymes needed to break down these carbohydrates. One such enzyme is amylase, which is found in saliva and starts the carbohydrate-digestion process, according to an article published in the “Journal of the American College of Nutrition” in 2009. You most likely wouldn’t get enough of these substances to have an effect on carbohydrate absorption through eating foods alone, however; you would have to take supplements to achieve a significant effect.
- MedlinePlus: Carbohydrates
- TeensHealth: Carbohydrates and Diabetes
- Diabetologia: Effect of Co-Ingestion of Fat on the Metabolic Responses to Slowly and Rapidly Absorbed Carbohydrates
- Food and Agriculture Organization of the United Nations: Physiological Effects of Dietary Fiber
- FAO: Digestion, Absorption and Energy Value of Carbohydrates
- Metabolism: Combining Protein and Carbohydrate Increases Postprandial Insulin Levels but Does Not Improve Glucose Response in Patients With Type 2 Diabetes
- Diabetes Spectrum: Protein Controversies in Diabetes
- Journal of the American College of Nutrition: Bean Amylase Inhibitor and Other Carbohydrate Absorption Blockers: Effects on Diabesity and General Health
- European Journal of Clinical Nutrition: The Effects of Fiber Enrichment of Pasta and Fat Content on Gastric Emptying, GLP-1, Glucose, and Insulin Responses to a Meal
Based in Massachusetts, Jessica Bruso has been writing since 2008. She holds a master of science degree in food policy and applied nutrition and a bachelor of arts degree in international relations, both from Tufts University.