Beans contain abundant protein with little fat and no cholesterol. Iron, calcium, vitamin C and folate are also among the nutrients in beans. As a carbohydrate-rich food, beans promote production of the neurotransmitter serotonin, which may make you feel sleepy. For those with diabetes or poor blood sugar control, however, another factor exists. By changing the amount of beans you eat or the foods you eat them with, you can enjoy beans with less risk of feeling tired.
Reactive Hypoglycemia
Beans are rich in carbohydrates, with around 15 g of carbohydrates in 1/2 cup of most cooked dried beans. Eating a large amount of beans or a bean dish with added sugar can raise your blood sugar, or blood glucose, quickly. Once your body has absorbed and used the glucose, you may experience reactive hypoglycemia, or sugar crash. This situation is more common with simple carbohydrates such as candy and white bread, than with complex carbohydrates such as beans and whole grains.
Beans and Blood Sugar
Choosing beans with a low glycemic index, meaning they raise blood sugar less quickly, can help keep your blood sugar stable. Cooked dried lentils, chickpeas and kidney beans have a glycemic index of around 29, while navy beans average 38 and black-eyed peas average 42, explain experts from the Harvard Medical School. Baked beans, which may contain added sugar, have an average GI of 48. In the diabetes exchange system, a 1/2-cup serving of most cooked dried beans counts as one carbohydrate and one protein exchange. For baked beans, however, just 1/3 cup counts as a carbohydrate and protein exchange.
Hypoglycemia Treatment
Sleepiness and weakness are symptoms of hypoglycemia, as are hunger, shakiness, sweating and dizziness. If you suspect hypoglycemia, check your blood sugar to ensure that it's above 70 mg/dL. If it's below 70 mg/dL, you can raise it to within a normal range with 1/2 cup fruit juice or non-diet soda, 1 cup milk, five or six pieces of hard candy or other source of glucose per your health care provider's directions. These items provide only temporary energy, so if your next meal is more than an hour away, eat a balanced snack that includes protein, fat and complex carbohydrates.
Preventing Reactive Hypoglycemia
To reduce risk of reactive hypoglycemia, limit the amount of beans you eat at one meal to a portion that covers no more than one-quarter of a 9-inch plate and is 1/2-inch high or less. That's around 1/2 cup of cooked beans. Choose high-fiber beans such as black beans and lima beans as well as low-GI beans. When you eat beans, include another protein source or healthy fat source in your meal to slow your rise in blood sugar. If you frequently experience hypoglycemia after carbohydrate-rich meals, consult your health care provider. You may need an adjustment in your diet plan or insulin dosage.
References
- University of Wisconsin-La Crosse: Wellness Resource Center: Healthy Eating: Carbohydrates
- Harvard Medical School: Glycemic Index and Glycemic Load for 100+ Foods
- MayoClinic.com; Diabetes: Exchange List: Starches; May 2010
- National Diabetes Information Clearinghouse: Hypoglycemia
- University of Idaho Extension: The Healthy Diabetes Plate: Starches
- MayoClinic.com; High-Fiber Foods; November 2009
