Your task after a diabetes diagnosis is to manage your intake of carbohydrates is a way that keeps those variations in blood glucose levels close to normal.
Carbohydrates, specifically molecules of the carbohydrate glucose, are your body’s favored fuel, and even though your cells can, and do, extract energy from protein and fat, glucose is choice numero uno. Glucose enters your bloodstream after you eat carbohydrates through absorption sites in your small intestine, and the rising glucose level in your blood signals special beta cells in the pancreas to release the hormone insulin.
Insulin stimulates cells, especially muscle, fat, and liver cells, to allow glucose molecules to pass through cell membranes where it can be stored inside of these cells for fuel when needed.
Cells store glucose in a molecule called glycogen, and glycogen is ready at a moment’s notice to jump into a metabolic cycle that spits out the power pack molecule adenosine triphosphate (ATP), the real fuel for everything requiring energy. Glycogen is your most accessible source of energy, and carbohydrates in your diet keep the supplies ready when needed.
The role of carbohydrates in your body is not limited to energy, by the way, although diabetes tends to focus attention on that role. Glycolipids (glucose plus lipids) are a component of cell membranes, glycoproteins help protect your sensitive tissues with mucus, and the five carbon sugar ribose is a component of DNA.
The sugar lactose is produced in the milk of nursing mothers, and helps humans and animals get the energy needed for growth, temperature regulation, and strenuous activity like crying. Milk sugar is the only significant carbohydrate component of your diet that is from an animal source, however, and most adults lose the ability to digest lactose.
Plants are your carbohydrate factories, and you can thank plant carbohydrates for the wood that built your house, and for the fuel you need every day to run your body. And many plant foods that contain carbohydrates also happen to come along with essential vitamins, minerals, antioxidants, and other compounds that work to keep you healthy.
Carbohydrate stores 4 calories of potential energy per gram, and excess carbohydrate in your diet is stored as fat. Excess consumption of carbohydrate, especially fructose, can also act to raise levels of low density lipoproteins, the so-called bad LDL cholesterol, and blood triglycerides.
High-fructose corn syrup gets its share of bad press, but in reality the fructose content of the most common formulation of this commercial sweetener, used in soft drinks, is only 5 percent higher than table sugar. Sucrose, table sugar, is one molecule of glucose bound to one molecule of fructose — 50 percent fructose.
Beyond being an important macronutrient for energy and nutrients, dietary carbohydrates are overwhelmingly the macronutrient most related to blood glucose levels. And, whether your love for carbohydrates and the calories they provide was important in contributing to your risk for diabetes or not, carbohydrates are certainly important now. Both type 1 and type 2 diabetes are characterized by blood glucose levels that don’t come back into normal balance after eating carbohydrate foods.
In type 1 diabetes your body loses the capacity to produce insulin, whereas in type 2 diabetes the cells needed for glucose storage become resistant to the influence of insulin. In both cases, your normal processes for converting food to energy are disrupted. A certain level of blood glucose is necessary to supply cells that don’t store glucose, like brain cells, with fuel whenever it’s needed.
But over time, persistently higher-than-normal levels of blood glucose damage tissues and significantly raise the risk for heart attack, stroke, nerve damage, vision loss, kidney failure, and other negative health impacts, innocently called complications. Controlling blood glucose with diabetes is a balancing act, and you’re the acrobat.
Your meal plan recommends you get as much as 50 percent of your daily calories from carbohydrate foods, but not all carbs are created equal. Carbohydrates include simple sugars like glucose, and also sugar molecules joined in chains that form starches and fiber.
Depending on how quickly the carbohydrates you eat are broken down during digestion and on the mix of carbs with other macronutrients when you eat, blood glucose can rise very rapidly or very slowly. Managing your diabetes means managing carbohydrates.