A1C Made Simple: Your Guide to Keeping Blood Sugar in Check

By Dr. Linda J. Dobberstein, DC, Board Certified in Clinical Nutrition

July 24, 2023

A1C Made Simple: Your Guide to Keeping Blood Sugar in Check
Currently in America, 88 million people, or 45% of all adults, have difficulties with slightly chronically increased blood sugar or prediabetes. By 2030, the number of people worldwide with prediabetes is expected to increase to more than 470 million. Prediabetes, like type II diabetes, is greatly impacted by diet and lifestyle. Periodic monitoring of your blood sugar levels informs you of your status, success, or need to make diet and lifestyle changes. Do you know what your hemoglobin A1C number is and how you can support your blood sugar management?

Hemoglobin A1C

Blood sugar levels can be measured by a fasting blood glucose test or after meals. Other blood tests like hemoglobin A1C measure your long-term control of blood sugar. Hemoglobin A1C is a weighted average of blood glucose levels during the preceding 2-3 months. This test is based on the life cycle of your red blood cells. The test can be conducted while fasting or non-fasting.

A healthy, non-diabetic A1C level ranges from 4.0-5.6%. Diabetes is defined as hemoglobin A1C at 6.5% and higher. Prediabetes is defined as an A1C level between 5.7 and 6.4%. Your diet and several other factors directly impact your A1C levels.

Every time you have a meal, snack, or beverage (not including water) your blood sugar elevates, and insulin is released. In a healthy individual, blood sugar levels return to premeal levels 2 hours after eating.

However, if you overeat, consume foods and beverages that rapidly spike your blood sugar, or eat frequently, it can cause your blood sugar to remain elevated for an extended period. Over time this causes your A1C to increase.

Non-Dietary Factors that Impact A1C

Your hemoglobin A1C can also be impacted by other factors. It may not be accurate if you are pregnant, have recent or heavy blood loss, or a blood transfusion. It may be inaccurate if you are anemic as iron deficiency and vitamin B12 or folate deficiency can falsely increase your A1C. Chronic alcohol consumption, chronic use of aspirin or opioids, treatment with steroids/glucocorticoids, severely elevated triglycerides and bilirubin levels, and other factors can also falsely elevate your A1C.

Drugs such as dapsone, ribavirin and sulfonamides that cause destruction of red blood cells may falsely lower A1C levels. If your spleen has been removed, this too affects your A1C.

Animal Foods and Cooking Methods

Animal proteins naturally contain “advanced glycation end products” or AGEs which contribute to increased hemoglobin A1C. Cooking proteins with high dry heat by grilling, broiling, roasting, searing, and frying accelerates the formation of AGEs in the food. Roasted seeds and nuts, butter, margarine, and other proteins also have higher levels of AGEs compared to grains, fruits, vegetables, beans, and legumes. AGEs amounts vary greatly in response to your method of cooking and heat.

An extensive list of AGE content in foods can be found in Table 1 of the Journal of the American Dietetic Association June 2010 article “Advanced Glycation End Products in Foods and a Practical Guide to Their Reduction in the Diet.”

Factors that Support Healthy A1C

Several factors support a healthy hemoglobin A1C, including diet quality, meal timing, exercise, fiber, minerals, and much more.

Diet Quality

Spend some time evaluating your diet. Be honest. Do you snack? Eat a lot of starches? Have added sugar or fructose-rich beverages between meals? Do you love to have your burgers and steaks grilled and well-done? How about crispy bacon? How is your A1C level?

The Leptin Diet is an easy to implement lifestyle plan that naturally incorporates intermittent fasting. Follow The Five Rules of the Leptin Diet as it is a great way to support healthy blood sugar and A1C.

• Rule 1: Never eat after dinner.
• Rule 2: Eat three meals a day.
• Rule 3: Do not eat large meals.
• Rule 4: Eat a breakfast containing protein.
• Rule 5: Reduce the amount of carbohydrates eaten.

Healthy blood sugar management and A1C are also supported by foods and beverages that have a low glycemic index and low glycemic load. These types of foods absorb slowly, are rich in fiber, and/or are minimally processed.

Numerous websites such as National Institutes of Health, Mayo Clinic, Cleveland Clinic, and Harvard University, and others, have food charts that list glycemic index and glycemic load of foods. For starters, avoid or reduce consumption of bagels, donuts, white rice, and food made with white flour and high amounts of starch. Reduce your intake of char-broiled or other AGE rich foods. Reduce or eliminate foods and beverages with added sugars.


Exercise is essential to help your body utilize and burn blood sugar. It enhances insulin sensitivity. Aerobic and strength training exercises are both proven to lower your A1C. The best exercises are those that you enjoy and can consistently perform. Aim for at least 180 minutes of exercise per week. Try exercising with a partner or trainer to keep you accountable.

Fructose Intake

Fructose, a type of dietary sugar, has been linked to adverse metabolic changes that affect weight management, blood sugar, and heart health. Studies demonstrated that individuals who consumed a low fructose diet improved their fasting blood glucose levels, hemoglobin A1C, as well as triglycerides and other cardiovascular markers.

In animals, high fructose consumption with a high fat diet (Western diet) has been found to cause surprising and unusual changes or elongation in the villi structure in the small intestine. This increased nutrient-calorie absorption resulting in weight gain and other adverse health changes.

Consider avoiding or reducing fructose-rich foods. Common sources include high fructose corn syrup, table sugar, honey, agave syrup, invert sugar, maple flavored syrup, molasses, palm or coconut sugar, sorghum, soda pop, juices, apples, grapes, watermelon, asparagus, peas, zucchini, and others. You may search use various apps or websites such as to evaluate nutrient content of foods and beverages.

Dietary Fiber and SCFAs

Dietary fiber greatly impacts the regulation of your hemoglobin A1C. Fiber slows down the spike in blood sugar. It helps keep blood sugar levels stable over longer periods of time and improves satiety. It helps stabilize the release of insulin in response to eating carbohydrates and protein.

Fiber also promotes the production of short chain fatty acids (SCFA) like butyrate in your intestinal tract. Fiber feeds the beneficial flora in your gut that allows them to diversify. It is linked to increased production of metabolic compounds, like glucagon-like peptide-1 production that help blood sugar management. These mechanisms have been shown to promote improvements in hemoglobin A1C.

Studies showed that 32 grams or more per day of dietary fiber supports gut flora diversity and short chain fatty acid production. This aided in healthier hemoglobin A1C.

Resistant starches such as those found in cooked, chilled white potatoes, oat bran, and steel cut oats consumed in moderation support your gut flora and short chain fatty acids. Resistant starches may support healthy blood sugar management and A1C.

Sodium and Potassium Balance

Your dietary intake of sodium and potassium also affects your A1C levels. A 2020 nutrition survey research study in China evaluated dietary intake of potassium and sodium in healthy adults. Results showed that high sodium/salt intake or high sodium relative to potassium intake was “significantly associated” with higher fasting glucose and HbA1C levels and higher risk for diabetes. Potassium is abundant in whole foods, especially fruits, vegetables, dairy, beans, legumes, and more.

Staying healthy is directly influenced by your daily habits and lifelong choices. Meal timing, food quality, exercise, stress management, sleep, and nutrient intake impact your health today and into the future. Blood sugar stability is vital for healthy weight, blood pressure, heart, brain and nerves, muscles, cartilage and joints, immune system, liver and detoxification, mitochondria, and your overall energy and vitality. As A1C levels increase, they put stress on every function and structure in your body. Keeping your hemoglobin A1C healthy now makes a difference for your quality of life tomorrow!

Share this content



Optimize cognitive performance!