Most adults with diabetes can lower their A1C by combining dietary changes, regular exercise, and better daily habits. The general target is an A1C below 7%, though your ideal number depends on your age and overall health. Because A1C reflects your average blood sugar over roughly three months, that’s also the minimum window you need before expecting to see changes on your next test.
What A1C Actually Measures
A1C tracks how much sugar has attached to your red blood cells’ hemoglobin over their lifespan, which ranges from 90 to 120 days. The higher your blood sugar runs during that window, the more sugar coats those cells, and the higher your A1C reads. This is why a single good week doesn’t move the needle. Sustained changes over two to three months are what show up on the test.
Most people with diabetes have their A1C checked at least twice a year. If you’re actively making changes or adjusting medication, your doctor may test every three months. If your result puts you in the prediabetes range, testing every one to two years is typical.
Shift Toward Lower Glycemic Foods
The single most impactful dietary change is choosing foods that raise blood sugar slowly rather than sharply. A low glycemic index eating pattern, one built around whole grains, legumes, non-starchy vegetables, and most fruits, lowers A1C by about 0.5 percentage points compared to a diet heavy in refined carbohydrates. That may sound small, but in clinical terms it’s meaningful, especially when stacked on top of other changes.
What this looks like in practice: swap white rice for brown or cauliflower rice, choose steel-cut oats over instant, and pair carbohydrates with protein or fat to slow digestion. You don’t need to eliminate carbs entirely. The goal is avoiding the sharp blood sugar spikes that come from processed grains, sugary drinks, and sweetened snacks.
Fiber plays a supporting role here. Soluble fiber, the kind found in oats, beans, lentils, and many fruits, dissolves in water and forms a gel-like substance in your stomach that slows sugar absorption. The federal dietary guidelines recommend 22 to 34 grams of total fiber per day depending on age and sex, but most Americans get far less. Increasing your fiber intake is one of the simplest ways to blunt post-meal blood sugar spikes.
Exercise: Combining Cardio and Strength Training
Physical activity lowers blood sugar both immediately (by pulling glucose into working muscles) and over time (by improving how well your body responds to insulin). The current recommendation for people with type 2 diabetes is at least 150 minutes per week of moderate-intensity aerobic exercise, things like brisk walking, cycling, or swimming.
But the strongest results come from adding resistance training on top of cardio. In one year-long study, people who did moderate resistance training combined with aerobic exercise three times per week dropped their A1C from 8.3% to 7.1%, a reduction of 1.2 percentage points. Another trial found that combined training lowered A1C from 7.7% to 6.9%, while aerobic exercise alone improved fitness but didn’t improve insulin sensitivity as much. The takeaway: lifting weights, using resistance bands, or doing bodyweight exercises a few days a week makes your cardio work harder for you.
You don’t need to train like an athlete. Three sessions per week that include both some form of cardio and some resistance work is the pattern that consistently shows results in clinical trials. Starting with even short sessions and building from there still moves your numbers in the right direction.
Why Weight Loss Matters, and How Much
Losing weight improves insulin sensitivity, which directly helps your body manage blood sugar. The landmark Diabetes Prevention Program found that losing just 5% of body weight, combined with increased physical activity, reduced the risk of progressing from prediabetes to diabetes by 58%. For someone weighing 200 pounds, that’s 10 pounds.
The effect of weight loss on A1C tends to be modest on its own, but it amplifies everything else you’re doing. Dietary changes become more effective when you’re also shedding excess fat, particularly visceral fat around the abdomen, which is closely linked to insulin resistance. Weight loss doesn’t have to be dramatic to be clinically useful.
Sleep and Stress Are Not Optional
Poor sleep directly undermines blood sugar control through several hormonal pathways. When you’re sleep-deprived, your body releases more stress hormones like cortisol, particularly in the evening when levels should be dropping. This drives up insulin resistance. At the same time, sleep restriction reduces the activity of hormones that help your pancreas respond to glucose, making your cells less effective at clearing sugar from the blood.
Short sleep also increases hunger by shifting the balance of appetite hormones: the hormone that signals fullness drops while the one that drives hunger rises. This makes it harder to stick with dietary changes, creating a cycle where poor sleep sabotages your eating habits and your blood sugar simultaneously. Chronic stress operates through many of the same mechanisms, keeping cortisol elevated and pushing your body into a state of sustained insulin resistance.
Aiming for seven to eight hours of consistent sleep and finding reliable ways to manage stress, whether through exercise, meditation, or simply protecting downtime, aren’t bonus strategies. They’re foundational to everything else working.
Tracking Blood Sugar in Real Time
Continuous glucose monitors (CGMs) have changed how people manage diabetes by replacing periodic finger pricks with a constant data stream. A large study of nearly 8,000 patients in a U.S. health plan found that starting CGM use was associated with clinically meaningful A1C reductions in both type 1 and type 2 diabetes. Most of the improvement happened in the first three months and held steady over 12 months.
The practical value of a CGM is that it shows you, in real time, how specific foods, activities, and sleep patterns affect your blood sugar. You can see that a bowl of white pasta spikes you for three hours while a lentil-based dish barely moves the line. That kind of immediate feedback accelerates learning and helps you fine-tune your habits faster than waiting for a quarterly A1C test.
What Medications Can Add
When lifestyle changes aren’t enough to reach your target, medications can produce significant additional A1C reductions. Metformin remains the most common starting medication for type 2 diabetes. For people who need more, newer injectable medications that mimic a gut hormone involved in blood sugar regulation have shown powerful results. In clinical trials, the most effective of these medications lowered A1C by over 2 percentage points when added to metformin, while also producing substantial weight loss. Others in the same class reduced A1C by roughly 1.0 to 1.5 points.
These medications work alongside lifestyle changes, not instead of them. The best outcomes in studies consistently come from people who combine medication with dietary improvements and regular exercise. If your A1C is well above target, medication may be necessary to bring it into a range where lifestyle changes can maintain control.
Realistic Timelines for Results
Because A1C reflects a three-month average, you need at least that long before expecting your next test to reflect your efforts. In practice, many people see the most noticeable A1C drop in the first three to six months of making changes, with a gradual leveling off as they approach their target. Studies on CGM users confirm this pattern: the biggest improvements come in the first three months and then sustain over time.
A reasonable expectation for lifestyle changes alone is a reduction of 0.5 to 1.0 percentage points over three to six months. Combined with medication, reductions of 1.5 points or more are common. If your starting A1C is 9% and your goal is under 7%, reaching that target may take six to twelve months of consistent effort, sometimes with medication adjustments along the way. Progress isn’t always linear, but the cumulative effect of stacking several strategies together is what produces lasting results.