Lowering your A1c comes down to a combination of dietary changes, regular exercise, better sleep, stress reduction, and in many cases medication. Most people can expect a meaningful drop within three months, since the A1c test reflects your average blood sugar over roughly the past 90 to 120 days, which is the lifespan of your red blood cells. Every strategy that keeps your blood sugar lower during that window will show up in your next result.
Why A1c Takes Months to Change
Your A1c measures how much sugar has attached to the hemoglobin inside your red blood cells. Because red blood cells live for about 90 to 120 days, the test captures a rolling average of your blood sugar over that period. This means no single great week will transform your number, but it also means no single bad week will ruin it. Consistent changes over two to three months are what move the needle.
Adjust What and How You Eat
Reducing carbohydrates is one of the most reliable dietary strategies. A meta-analysis comparing low-carbohydrate diets to low-fat diets in people with type 2 diabetes found that low-carb eating reduced A1c by an average of 0.41 percentage points within three months. That’s a clinically meaningful shift from diet alone. The advantage faded at six and twelve months in studies, likely because adherence drops over time, which tells you something important: the diet that works is the one you can stick with.
You don’t need to go extremely low-carb. The core principle is swapping refined carbohydrates (white bread, sugary drinks, pastries) for fiber-rich options (vegetables, legumes, whole grains) that release glucose more slowly. Pairing carbohydrates with protein or fat at meals also blunts blood sugar spikes. Some people find it helpful to eat their largest carbohydrate portion at lunch rather than dinner, since insulin sensitivity tends to be higher earlier in the day.
Nutrition interventions that focus specifically on metabolic control rather than just weight loss have been shown to improve A1c by 1 to 2 percentage points, according to research published by the American Diabetes Association. That’s a substantial change and often enough to shift someone from a concerning range into a well-managed one.
Move Your Body Regularly
Both aerobic exercise (walking, cycling, swimming) and resistance training (weights, bands, bodyweight exercises) lower A1c by similar amounts. Resistance training alone reduces A1c by about 0.39 percentage points compared to no exercise, and studies show no significant difference when comparing it head-to-head with aerobic training. The best approach is to do both, but if you’re choosing one, pick whichever you’ll actually do consistently.
Exercise works through multiple pathways. Your muscles pull glucose out of your bloodstream during activity, and they remain more sensitive to insulin for hours afterward. Resistance training adds muscle mass over time, which increases your body’s capacity to store and use glucose around the clock. Aim for at least 150 minutes of moderate activity per week, spread across most days rather than crammed into weekends.
Lose a Modest Amount of Weight
You don’t need dramatic weight loss to see results. Losing 5 to 10% of your starting weight is achievable for most people and was the target in landmark studies like the Diabetes Prevention Program, which reduced the risk of developing diabetes by 58%. For someone weighing 200 pounds, that’s 10 to 20 pounds.
Interestingly, blood sugar improvements often start before much weight comes off. Researchers have observed that the metabolic benefits appear quickly, likely driven by changes in how your body processes nutrients rather than by fat loss itself. This is encouraging if the scale feels slow: your blood sugar may already be improving even in the early weeks of a new routine.
Sleep Enough, but Not Too Much
Sleep has a surprisingly direct effect on blood sugar. Research shows a U-shaped relationship between sleep duration and A1c: both too little and too much sleep are linked to higher levels. Insufficient sleep raises cortisol, a stress hormone that pushes blood sugar up. It also makes you hungrier, less motivated to exercise, and more likely to reach for high-carb comfort foods.
Most adults do best with seven to eight hours. If you snore heavily, wake up gasping, or feel exhausted despite a full night in bed, sleep apnea could be silently worsening your blood sugar control. Treating it often leads to measurable improvements in glucose levels.
Manage Chronic Stress
Stress isn’t just a feeling. Higher cortisol levels suppress your pancreas’s ability to produce insulin, even within the normal physiological range. A large population study found that people in the highest third of cortisol levels were 26% more likely to have reduced insulin production compared to those in the lowest third. Over time, this translates directly into higher blood sugar and a higher A1c.
Effective stress management looks different for everyone. Regular physical activity counts double here since it lowers both stress and blood sugar. Other approaches with evidence behind them include mindfulness practices, adequate sleep (which reduces stress perception), and simply identifying and reducing avoidable sources of chronic pressure in your life.
Consider Continuous Glucose Monitoring
Wearing a continuous glucose monitor (CGM) lets you see in real time how your body responds to specific foods, exercise, stress, and sleep. This feedback loop can be powerful. In a study of people with type 2 diabetes, long-term CGM use was associated with an A1c reduction of 0.6 points at both 6 and 12 months, dropping the median A1c from 8.4 to 7.6. Even at 24 months, users maintained a 0.4-point reduction.
The value of a CGM is that it turns abstract advice into personal data. You stop guessing which foods spike your blood sugar and start seeing it directly. Many people discover that foods they assumed were safe (like certain fruits, rice, or oatmeal) cause larger spikes than expected, while other meals they feared are perfectly fine. This personalized feedback often motivates dietary changes more effectively than general guidelines.
Understand Your Medication Options
When lifestyle changes aren’t enough on their own, medication can produce significant A1c reductions. The first-line option for most people with type 2 diabetes works by reducing the amount of glucose your liver releases and improving your body’s sensitivity to insulin. It typically lowers A1c by 1 to 1.5 percentage points.
A newer class of injectable and oral medications that mimic a gut hormone involved in blood sugar regulation has shown even larger effects. The most potent options in this class reduce A1c by 1.5 to 2.2 percentage points when added to existing treatment. These medications also promote weight loss, which provides additional blood sugar benefits. Your provider can help determine whether adding or adjusting medication makes sense based on your current A1c and how you’ve responded to lifestyle changes.
Know When Your A1c Might Be Misleading
Certain conditions can make your A1c read higher or lower than your actual blood sugar average. Iron deficiency anemia, which is common in women and vegetarians, tends to push A1c readings artificially high. On the other hand, any condition that shortens the lifespan of your red blood cells (recovery from blood loss, certain types of anemia, kidney dialysis) will make your A1c read falsely low.
Genetic hemoglobin variants, which are more common in people of African, Mediterranean, and Southeast Asian descent, can also interfere with the accuracy of certain A1c testing methods. If your A1c results don’t match what your daily blood sugar readings suggest, ask about alternative tests like fructosamine or glycated albumin that measure blood sugar control over a shorter window and aren’t affected by red blood cell turnover.