What blood sugar level is a hemoglobin A1c of 5.7%?

An HbA1c of 5.7% corresponds to an estimated average glucose (eAG) of about 117 mg/dL (6.5 mmol/L) over the past 2–3 months. That sits just above the normal range and marks the start of prediabetes.

Is hemoglobin A1c 5.7% reversible?

Yes. 5.7% is the very start of prediabetes and often reversible. The Diabetes Prevention Program found that intensive lifestyle changes — at least 150 minutes of exercise weekly plus a goal of at least 7% weight loss — cut progression to type 2 diabetes by 58% over about three years, outperforming metformin.

How long does it take to lower an A1c of 5.7%?

Because HbA1c reflects a 2–3 month average, retest after about 3 months of consistent changes. How much it falls in that window varies from person to person; steady diet, exercise, and modest weight loss are the changes most likely to bring it back below 5.7%.

Is an A1c of 5.7% high or bad?

5.7% is only mildly elevated and not diabetes — it is the very bottom of the prediabetes band (5.7–6.4%). It sits just one tenth of a percent above the normal cutoff of 5.6%. It is best read as an early-warning signal, not a bad result: many people at this level return to normal, especially with lifestyle change.

Are glycohemoglobin, glycated hemoglobin, Hgb A1c and HbA1c the same test?

Yes. Glycohemoglobin, glycated hemoglobin, Hgb A1c, A1C and HbA1c are all names for the same test — the percentage of your hemoglobin that has glucose attached. A glycohemoglobin of 5.7% and an HbA1c of 5.7% mean exactly the same thing.

Is an HbA1c of 5.8% prediabetes?

Yes, by the American Diabetes Association's range (5.7–6.4%), though it is early prediabetes and diabetes starts at 6.5%. UK guidance from NICE starts its high-risk range at 6.0%, so a 5.8% may not be flagged there. It corresponds to an average glucose of about 120 mg/dL (6.6 mmol/L).

Is HbA1c 6.0% diabetic?

Not yet. 6.0% is prediabetes; the diabetes threshold is 6.5%. But 6.0% sits in the upper half of the prediabetes band, with an average glucose of about 126 mg/dL (7.0 mmol/L), so it is closer to the diabetes line than to normal — a strong reason to act now, while the change is still easy to reverse.

HbA1c 5.7%, 5.8% or 6.0%: What Your Prediabetes Number Means

You got your lab results back. Your HbA1c is 5.7%. Your doctor mentioned the word "pre-diabetic," and now you're worried.

Before you panic: an HbA1c of 5.7% is not a death sentence. But it is a wake-up call—and a pivotal moment where lifestyle changes can literally change your future.

Here's what that number means, why it matters, and exactly what to do about it.

What HbA1c Actually Measures

HbA1c (hemoglobin A1c) is a blood test that measures your average blood glucose over the past 2-3 months. It's one of the standard tests for diagnosing diabetes and a core test for monitoring long-term glucose control.¹ A continuous glucose monitor shows the same story minute by minute — covered in using a CGM without diabetes.

You may see this same test written several different ways on a lab report — glycohemoglobin, glycated hemoglobin, Hgb A1c, A1C, or HbA1c. They are all the same measurement: the percentage of your hemoglobin that has glucose bound to it.² So a glycohemoglobin of 5.7% and an HbA1c of 5.7% mean exactly the same thing. (It's also worth clearing up one common mix-up: an A1c of 5.7% is not the same as a hemoglobin of 5.7 g/dL — that second number would signal severe anemia. This page is about the A1c percentage.)

How It Works

Red blood cells live approximately 120 days. Glucose binds to hemoglobin (a protein in red blood cells) in a process called glycation. The more glucose in your blood over those 120 days, the more hemoglobin gets glycated.¹ When your doctor measures HbA1c, they're essentially measuring what percentage of your hemoglobin has been "sugar-coated."

It's elegant because it can't be gamed. You can't fake a good HbA1c result by eating well the day before your test. It's a weighted average of roughly the past 3 months, with recent weeks counting most.¹

Why It's Better Than Fasting Glucose

Fasting glucose tells you your blood sugar right now. It's useful but incomplete—like checking the weather on one day and assuming that's the climate for the whole season.

HbA1c is like an average temperature over 90 days. In a large US cohort it predicted diabetes at least as well as fasting glucose and was more strongly linked to cardiovascular disease.³

HbA1c Classification (ADA 2025 Standards of Care)

The American Diabetes Association provides clear, evidence-based thresholds:

Normal: <5.7%
Prediabetes: 5.7% – 6.4%
Diabetes: ≥ 6.5%¹

At 5.7%, you're right at the threshold. You're not diabetic. But you're not in the normal range either.

Is an A1c of 5.7% Bad? Is It Reversible?

Short answer: it's not bad, and yes — at this level it's often reversible.

Is it high? Only mildly. 5.7% is the very floor of the prediabetes band, one tenth of a percent above the normal cutoff of 5.6%. It is still well below the diabetes line of 6.5%. Think of it as the earliest possible warning light, not a red alert.

Is it reversible? Yes, and the evidence is unusually strong. The Diabetes Prevention Program — the landmark trial covered in detail below — found that moderate lifestyle change (at least 150 minutes of exercise a week plus a goal of at least 7% weight loss) cut progression to type 2 diabetes by 58% over about three years, beating metformin.⁴ Because 5.7% sits at the very start of the range, you have the shortest distance to travel back to normal of anyone in the prediabetes band. Many people do get back to normal: across cohort studies, 33–59% of people with prediabetes returned to normal glucose levels within one to five years.⁵

So what should you actually do? Don't panic, and don't ignore it either. The single number to focus on is your estimated average glucose: an A1c of 5.7% works out to roughly 117 mg/dL.⁶ Run your own number with the free A1C to blood sugar calculator, then use the 90-day protocol further down this page to bring it down.

What 5.7% Means for Your Health

An HbA1c of 5.7% means your average blood glucose over 3 months has been approximately 117 mg/dL. Run your own number with the free A1C to blood sugar calculator.

For perspective:

Normal fasting glucose: 70–99 mg/dL
Normal 2-hour glucose on an oral glucose tolerance test: <140 mg/dL¹
A 3-month average of 117 mg/dL suggests frequent post-meal glucose spikes and/or sustained elevated fasting glucose

Your Risk

With HbA1c in the 5.7–6.4% range:

Type 2 diabetes risk: in pooled cohort data, a 5-year diabetes incidence of roughly 9–25% at A1C 5.5–6.0%, rising to 25–50% at 6.0–6.5%¹
Cardiovascular risk: Already slightly elevated compared to normal glucose⁷
Reversibility: Often reversible, especially with lifestyle changes⁵⁴

The critical point: you're at a crossroads. The direction you go now determines whether you develop type 2 diabetes or return to normal.

HbA1c 5.8%, 6.0% and Higher: Where You Sit in the Range

The prediabetes band is wide, and where you sit in it changes the odds. Each value converts to an estimated average glucose with the ADAG formula (eAG = 28.7 × A1C − 46.7):⁶

HbA1c	Average glucose (mg/dL)	Average glucose (mmol/L)	Where it sits
5.7%	117	6.5	Start of prediabetes
5.8%	120	6.6	Early prediabetes
5.9%	123	6.8	Early prediabetes
6.0%	126	7.0	Upper prediabetes
6.2%	131	7.3	Upper prediabetes
6.4%	137	7.6	Top of the prediabetes range
6.5%	140	7.8	Diabetes threshold

HbA1c 5.8%

5.8% is prediabetes by the ADA's range, but only just; UK guidance from NICE starts its high-risk range at 6.0%, so a 5.8% may not be flagged there.⁷ At A1C 5.5–6.0%, a systematic review put the 5-year risk of developing diabetes at 9–25%.⁸ It is also the easiest place to turn around: DPP-style lifestyle programs in the US lowered HbA1c by about 0.2 points on average, enough to bring many people at 5.8% back below 5.7%,⁹ and in DPP follow-up, getting back to normal glucose even once was linked to a 56% lower risk of later diabetes.¹⁰

HbA1c 6.0%

6.0% sits in the upper half of the band, closer to diabetes than to normal, and counts as high risk under NICE's narrower 6.0–6.4% range.⁷ For an A1C of 6.0–6.5%, the same review put the 5-year risk at 25–50%,⁸ and roughly 5–10% of people with prediabetes progress to type 2 diabetes each year if nothing changes.¹¹ Because 126 mg/dL is a 24-hour average, after-meal readings are almost certainly higher, and those spikes matter: in pooled European cohorts, glucose two hours after a glucose drink predicted death better than fasting glucose did.¹² The levers are the same as at 5.7%, with more urgency: weight loss was the main driver of the DPP's results,¹³ a 10–15 minute walk after meals blunts the spike that A1C averages,¹⁴ and pairing A1C with fasting insulin shows how hard your body is working to hold glucose there.¹⁵

HbA1c 6.4% and 6.5%

6.4% is the top of the prediabetes range; at 6.5% the ADA's diabetes threshold is reached, and a diagnosis needs a second abnormal result unless symptoms are clear.¹ What to do at that point is covered in HbA1c 6.5%: the diabetes threshold. If your fasting glucose is borderline too, see fasting glucose 100 to 125 mg/dL.

Why You're Here: Root Causes of Prediabetes

Prediabetes develops from a combination of:

1. Insulin Resistance

Your cells (especially muscle and fat cells) don't respond to insulin signals as well as they should. Your pancreas compensates by producing more insulin; glucose starts to rise once that extra insulin is no longer enough to compensate.¹ This is often driven by:

Excess body weight, especially belly fat (visceral adiposity)
Sedentary lifestyle¹
Poor diet (high refined carbs, sugar, ultra-processed foods)
Inflammation (often linked to lifestyle)

2. Pancreatic Beta Cell Dysfunction

Your pancreatic beta cells, which produce insulin, may not be releasing enough insulin or at the right times. This can be genetic, but lifestyle can influence progression.¹

3. Genetic Predisposition

Type 2 diabetes runs in families. If a parent, sibling, or close relative has type 2 diabetes, your risk is substantially elevated.¹⁶ But genetics are not destiny—lifestyle modifications still work even with genetic risk.¹⁷

Most people with prediabetes have a combination of all three factors.

The Good News: Proven Lifestyle Interventions

Here's what research actually shows works:

The Diabetes Prevention Program (DPP)

The landmark Diabetes Prevention Program followed 3,234 people with prediabetes. They were randomly assigned, in roughly equal thirds, to an intensive lifestyle intervention, to metformin, or to placebo with standard lifestyle advice.⁴

Results after 3 years:

Lifestyle intervention group: 58% reduction in type 2 diabetes progression (71% reduction in people 60+)
Metformin group (for comparison): 31% reduction⁴

This is one of the most important studies in diabetes medicine. Lifestyle beats medication.

What the Lifestyle Intervention Included:

1. Weight Loss: at least 7% of body weight (the DPP goal)

Even modest weight loss is transformative. If you weigh 200 lbs, losing 10-14 lbs (5-7%) significantly improves insulin sensitivity.¹⁶¹⁸

How?

Visceral fat (around organs) is highly metabolically active and inflammatory.¹⁹ Losing even a small amount improves insulin signaling.
In the DPP, each 1 kg of weight lost cut the risk of developing diabetes by about 16%.¹³

2. Aerobic Exercise: 150 minutes/week minimum

The magic number: 150 minutes per week of moderate-intensity aerobic activity (brisk walking, cycling, jogging, swimming).²⁰²¹

Why it works:

Muscle is insulin-sensitive. Contracting muscle takes up glucose without needing insulin.²²
Aerobic exercise increases mitochondrial density, improving metabolic efficiency.²²
It reduces visceral fat.²³
Even one bout of exercise improves glucose control for hours afterward.²²

Start with 30 minutes, 5 days/week. Progress gradually.

3. Resistance Training: 2 days/week

Strength training complements aerobic work:²⁰

Builds muscle mass (which is glucose-hungry and insulin-sensitive)²²
Improves resting metabolic rate²⁴

Examples: Weight lifting, bodyweight exercises (push-ups, squats), or resistance bands. 2 sessions/week, targeting all major muscle groups.²¹

4. Dietary Changes

The DPP didn't prescribe a named diet; its nutrition counseling focused on cutting calories and total fat.²⁰ But research shows these principles matter:

Reduce refined carbs: Replace white bread, sugary cereals, and pastries with whole grains, legumes, and vegetables.²⁰
Increase fiber: Aim for about 25g daily (women) and 38g daily (men) up to age 50, or 21g and 30g after that.²⁵ Fiber slows glucose absorption.
Choose lean proteins: Fish, poultry, legumes, low-fat dairy.
Limit added sugar: <10% of total calories (roughly <50g/day for a 2000-cal diet), the WHO ceiling for free sugars.²⁶
Emphasize whole foods: Minimize ultra-processed foods.
Portion control: Even healthy foods contribute to weight gain if portions are too large.

No diet is perfect. But consistency beats perfection.

The Timeline: When to Expect Changes

2 weeks: Day-to-day glucose can start to improve, especially after meals²²
4-8 weeks: HbA1c may start to improve (though full effect takes 3 months)¹
3 months: Meaningful HbA1c reduction is measurable
6-12 months: Potential reversal to normal HbA1c range

Should You Take Metformin?

Metformin is a diabetes medication often offered to people with prediabetes. It reduces diabetes progression by ~31% (DPP data). That's helpful, but less powerful than lifestyle change.

When metformin might be considered:

Age 25-59 with BMI ≥35 kg/m²
Higher fasting glucose (e.g., ≥110 mg/dL) or higher A1C (e.g., ≥6.0%)
Prior gestational diabetes²⁰

Important: Metformin is not a replacement for lifestyle change—it's an adjunct. Even if you take it, diet and exercise still matter.

Side effects: Gastrointestinal upset (manageable with extended-release formulations), rare but serious lactic acidosis (with severe kidney disease).²⁷

Monitoring and Follow-Up

Retest Timing

Retest HbA1c in 3 months after starting interventions
If improving, retest every 6-12 months (guidelines suggest at least yearly monitoring with prediabetes)²⁰
If stable or worsening, reassess with your doctor (may need medication)

Additional Tests Worth Considering

Fasting glucose: 100-125 mg/dL = prediabetic range 2-hour oral glucose tolerance test (OGTT): 140-199 mg/dL = prediabetic range¹ Fasting insulin: Elevated levels suggest insulin resistance

These can help confirm prediabetes and guide treatment intensity.

Action Plan: Next Steps

Week 1

Schedule a follow-up appointment with your doctor in 3 months
Ask for a referral to a registered dietitian if available (nutrition expertise makes a huge difference)²⁰
Start journaling food intake (awareness is step one)

Weeks 2-4

Establish a walking routine: 30 minutes, 5 days/week (can be broken into 10-minute segments)
Identify and swap 2-3 high-sugar or refined-carb foods for whole-food alternatives
Start resistance training: 2 sessions/week (even bodyweight exercises count)

Months 2-3

Reassess weight (should be trending down if 5-7% loss is the goal)
Retest HbA1c at the 3-month mark
Evaluate progress; adjust if needed

The Mindset Shift

HbA1c 5.7% is not a diagnosis of disease. It's a measurement of metabolic drift. And drift can be corrected.

The people who reverse prediabetes successfully don't usually go on crash diets or become obsessive about exercise. They make sustainable changes: they walk more, eat whole foods most of the time, lose a modest amount of weight, and build strength.

These changes have benefits far beyond glucose: improved energy, better sleep, reduced disease risk, improved mental health, and often—weight loss leads to increased confidence and motivation.

Your HbA1c of 5.7% is the gift of early warning. Use it.

Tracking your health metrics over time reveals patterns a single reading can't. Start tracking yours →

Medical Disclaimer

This article is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. HbA1c interpretation and diabetes classification should always be done by a qualified healthcare provider in the context of your complete clinical picture. Recommendations regarding lifestyle intervention, weight loss goals, and medication should be individualized and made in consultation with your physician. If you have been diagnosed with prediabetes or diabetes, work closely with your healthcare team, including a registered dietitian, to develop a personalized management plan. Information here is based on the ADA 2025 Standards of Care in Diabetes and the Diabetes Prevention Program research, but individual circumstances vary.