A fasting blood sugar test measures the amount of a type of sugar, called glucose, in the blood after the person has not eaten for at least eight hours. Checking for an ideal fasting blood sugar is one of the most commonly performed tests to check for prediabetes and type 2 diabetes.
Fasting blood sugar ranges are the following:
- The normal blood sugar range is 65-99 mg/dL.
- If the fasting blood sugar is between 100 and 125 mg/dL, it is considered “impaired fasting glucose,” also referred to as “prediabetes.”
- If the fasting blood sugar is more than 126 mg/dL on two or more occasions, it is diagnosed as full-blown diabetes.
People defined as having impaired fasting glucose/prediabetes are individuals whose blood sugar levels do not meet criteria for diabetes, yet are higher than those considered normal. These people are at relatively high risk for the future development of diabetes. According to the American Diabetes Association (ADA), prediabetes is not a disease itself but rather a risk factor “for diabetes as well as cardiovascular disease.”
However, the ADA also state that prediabetes can be considered an “intermediate stage” in the diabetes disease process. (One might wonder how prediabetes can be a both a risk factor for diabetes and an intermediate stage of the diabetes disease process simultaneously).
In addition to increasing the chance of developing diabetes, it’s well-established that people with impaired fasting glucose/prediabetes are more likely to be overweight or obese, especially with what’s known as abdominal or visceral obesity. They also are more likely to have high triglycerides and/or low HDL cholesterol, and hypertension.
Risk of Higher Than Ideal Fasting Blood Glucose Levels
Studies show that even those with fasting blood sugar levels towards the high end of the optimal glucose level may be at significantly higher risk. In fact, these cut-offs for what are considered “normal,” prediabetes, and diabetes blood sugar ranges are somewhat arbitrary. The truth is that blood sugar starts damaging body tissues and increasing the risk of numerous diseases even at levels lower than prediabetes levels.
A panel of experts gathered by the American College of Endocrinology and the American Association of Clinical Endocrinologists confirmed this in 2008 when they reviewed all the science on prediabetes and diabetes. They found that the risks of having elevated blood sugar—including heart disease, strokes, kidney damage, nerve damage, dementia, and cancer—start at numbers much lower than those used to diagnose pre-diabetes or diabetes.
In other words, even if the normal fasting glucose level falls within the optimal range, they could still be damaging your heart, brain, and other tissues—and setting the person up for diabetes symptoms down the road.
Optimal Blood Glucose Levels
Some studies indicate that an ideal fasting glucose level is less than 90 mg/dl and likely somewhere around 85 mg/dl. However, the optimal fasting blood glucose level likely depends on additional factors related to blood sugar regulation. The fasting blood sugar test provides only a small amount of information regarding how the body handles sugar. There are other important tests, such as the glucose tolerance test, the insulin response test, and the Hemoglobin A1c test, which are considered by many experts to be more important indicators of prediabetes and other problems with blood sugar metabolism.
How to Lower Blood Sugar Levels
If the fasting blood sugar is above 85 or 90 mg/dl it can be lowered. There are many factors that can improve blood sugar control. It all comes back to the basics:
- Adopts a diabetic diet that boosts intake of healthy foods while decreasing intake of sugar and empty carbs.
- Exercise regularly.
- Reduce stress.
There are many useful natural therapies and dietary approaches for hypoglycemia and lowering blood sugar. See below for more information:
- Suffering from High Blood Sugar Symptoms? Use This Glycemic Index Food List
- The Best Metabolic Syndrome Diet
- Could This Diet for High Blood Sugar Be the Single Healthiest Diet for Everyone?
Originally published in 2018, this post is regularly updated.