Background
You hear the term “blood sugar” thrown around a lot. You’re told to keep it within a certain range to feel your best and minimize your risk for chronic disease. But what exactly is blood sugar, and what’s the best way to keep it in check? Let’s find out.
When we say blood sugar we’re talking about a carbohydrate called glucose, which is one of the main sources of energy for the body’s cells. Glucose is a monosaccharide, or single unit sugar molecule. Monosaccharides can be combined to produce disaccharides such as sucrose (table sugar, which is one unit of glucose + one unit of fructose) and lactose (glucose + galactose, the sugar found in milk). A string of several monosaccharides is called a polysaccharide; examples include fiber and starch.
Your digestive system breaks down carbohydrates into glucose, which is then moved into the body’s cells with the help of a hormone called insulin. Once inside the cells, glucose turns into energy in the form of the molecule ATP. If you eat more glucose than your body needs, the excess is stored as glycogen in muscle cells or triglycerides in fat cells.
Healthy Ranges
The American Diabetes Association defines normal fasting (meaning that you’ve had nothing but water for at least 8 hours before the test) blood glucose levels as 100 mg/dL or less. 100-125 mg/dL indicates prediabetes, and 126 mg/dL or higher indicates diabetes. Postprandial (after-meal) glucose levels should not exceed 140 mg/dL in healthy individuals.
Another blood glucose test called the hemoglobin A1C test measures your average blood sugar over the past 2-3 months. Hemoglobin is a protein in red blood cells; the A1C test measures the percentage of red blood cells with sugar attached to them. A normal A1C is less than 5.7%, a prediabetic A1C is 5.7%-6.4%, and a diabetic A1C is 6.5% or higher.
Symptoms of hyperglycemia (high blood sugar) may include headache, increased thirst/hunger, and fatigue, while hypoglycemia (low blood sugar) is associated with weakness, shakiness, and anxiety. Fluctuating blood sugar can lead to energy spikes and crashes, and persistently elevated blood glucose can cause chronic inflammation and insulin resistance. This can interfere with weight management and increase your risk of chronic disease such as diabetes, cardiovascular disease, and Alzheimer’s disease.
Tips For Keeping Blood Sugar Stable
- Choose whole grains over refined grains: Refined carbohydrates (e.g. white bread and white rice) lack healthy components such as fiber, which can help prevent sudden blood sugar spikes.
- Don’t eat “naked carbs”: Pairing carbohydrates with other macronutrients such as protein and fat helps to slow the release of sugar into the bloodstream.
- Watch out for added sugar: The revised nutrition facts label has a section for added sugar — pay attention to this to choose products with less.
- Exercise: Exercise lowers blood sugar levels and improves insulin sensitivity. Try going for a light walk after meals.
- Be mindful of alcohol use: Drinking on an empty stomach can cause low blood sugar by interfering with the liver’s ability to make new glucose from non-carbohydrate sources (a process known as gluconeogenesis). To avoid symptoms of hypoglycemia, pair your drink with a meal or snack.