Insulin is a hormone that helps transport blood glucose into the body's cells for storage or fuel. A diet high in processed carbohydrates, such as sugar and white bread, can lead to heightened insulin levels. Over time, this can trigger insulin resistance and type 2 diabetes. Low-carbohydrate diets and diets high in complex carbohydrates can help prevent elevated insulin levels.
Insulin
When you eat, your digestive system converts the components of the food into molecules that can enter your bloodstream. Carbohydrates are converted into glucose, protein is converted into amino acids and fat is converted into protein-covered fat molecules. When these constituents enter the bloodstream, the pancreas responds by releasing insulin. Insulin then helps carry the food components to the cells for storage or cell fuel.
Insulin Resistance
When you eat too much food or stay on a diet containing mostly processed carbohydrates, you trigger the pancreas to produce excess insulin. Over time, excess insulin can make the insulin receptors on the body's cells shut down. This condition is called "insulin resistance." When you are insulin-resistant, your body does not have an effective way of carrying energy sources into your cells. As a result, the cells are starving. This makes the pancreas produce more insulin. The excess insulin can lead to plague formation in blood vessels and can cause the pancreas to shut down. Severe cases of insulin resistance are also known as type 2 diabetes.
Low-Carbohydrate Diets
The digestive system breaks down different food components at different rates. Carbohydrates are generally the first components to break down and enter the bloodstream. These molecules, therefore, cause the greatest peaks in insulin levels. Diets that reduce carbohydrate intake can help prevent steep peaks in insulin. The most well-known of the low-carbohydrates diets is the Atkins Diet. On this diet, carbohydrates are kept to about 20 g per day in the beginning phases and up to 100 g in later phases. This is significantly less than the 225 to 325 g of carbohydrates recommended by the government's official food guidelines.
Low-Glycemic-Index Diets
There is some controversy over whether it is healthy to severely cut the intake of carbohydrates. Judith Wurtman, director of the Adara Weight Loss Center in Boston, suggests that cutting carbohydrates may lead to low levels of the happiness neurotransmitter serotonin. Low levels of serotonin can result in anxiety and depression. The low-glycemic-index diet is an alternative to the low-carbohydrate diet that does not require cutting your intake of carbohydrates. This diet is based on the principle that some carbohydrates break down faster than others. Carbohydrate-rich foods that break down very fast, including candy, white bread and white rice, have a high glycemic index. The low-glycemic-index diet encourages eating carbohydrates, such as vegetables, whole-grain bread and pasta and legumes, that break down more slowly. A diet that consists of foods that break down at a slower rate in the digestive system can help prevent steep peaks in insulin levels.
References
- MayoClinic.org: Diabetes and Insulin
- MayoClinic.com: Is the Glycemic Index Diet Useful for People with Diabetes?
- Atkins diet: What's Behind the Claims?
- Health.Gov: Dietary Guidelines for Americans 2005
- "Psychology Today"; Low-Carb State of Mind; Brenda Goodman; March 1, 2004
- MIT News: Carbs are Essential for Effective Dieting and Good Mood, Wurtman Says; Elizabeth A. Thomson; Feb. 20, 2004
