HbA1c: 5.1

What does an A1c level of 5.1 mean?

A hemoglobin A1c (aka HbA1c or A1c) level of 5.1 is considered optimal. 

An A1c of 5.1 means that 5.1% of the hemoglobin in your blood is saturated with sugar. A1c levels between 4 and 5.6 percent indicate good blood glucose control over the last 2-3 months. Maintaining an optimal A1c is important for preventing diabetes and the complications associated with this diagnosis.

How to maintain optimal A1c levels

An A1c level of 5.1% means you have had good blood glucose control over the last few months. A1c typically increases with age [4], so it’s important to have your levels checked every so often, particularly if you’re at greater risk for developing prediabetes or diabetes. 

Groups that are at greater risk for developing prediabetes/ diabetes include: 

  • Adults age 45 or older

  • People of Black, Hispanic/Latino, American Indian, Asian American, or Pacific Islander descent

  • Individuals with a parent, brother, or sister with diabetes

  • Those who are overweight or obese

  • People who are physically inactive 

  • Individuals with low HDL (good) cholesterol and/or high triglycerides

  • Those with high blood pressure, or who take medicine for high blood pressure

  • Women who had diabetes during pregnancy or who have been diagnosed with polycystic ovary syndrome (PCOS)

Regardless of whether or not you’re at increased risk for prediabetes/ diabetes, having a healthy, balanced diet and lifestyle are key to maintaining optimal A1c levels. Here are some things you can do to keep your levels in the green: 

  • Be active every day. Get 150 minutes of moderate physical activity per week (about 30 minutes, 5 days per week). 

  • Fill half of your plate with non-starchy veggies at every meal, and incorporate a source of lean protein and plant-based fat to assist with blood sugar control. 

  • Limit refined carbohydrates and added sugar, and choose whole-grain carbs such as whole wheat bread/ pasta, quinoa, farro, and steel-cut oats, instead. 

  • Lose excess weight if you are overweight or obese.

  • Follow your diabetes treatment plan if you have been diagnosed with diabetes.

  • Manage stress and get adequate sleep to help balance hormone levels that can affect blood sugar.


  1. All About Your A1C. (2018, August 21). Centers for Disease Control and Prevention.


  2. Diabetes Risk - What Causes Diabetes. (n.d.). American Diabetes Association. Retrieved September 14, 2021, from


  3. Cherney, K. (2020, June 18). A Complete List of Diabetes Medications. Healthline.


  4. Pani, L. N., Korenda, L., Meigs, J. B., Driver, C., Chamany, S., Fox, C. S., Sullivan, L., D'Agostino, R. B., & Nathan, D. M. (2008). Effect of aging on A1C levels in individuals without diabetes: evidence from the Framingham Offspring Study and the National Health and Nutrition Examination Survey 2001-2004. Diabetes care, 31(10), 1991–1996.