Prediabetes: What It Actually Is and What Actually Changes It
Your A1C is in the gray zone. Here's what the research says about reversing it — before it becomes type 2 diabetes.
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Most people with prediabetes don't know they have it — and that's the whole problem.
Your A1C is 5.9. Your doctor says "watch it." You leave the office with a pamphlet and a vague sense of dread, but no real map for what to actually do. That's the prediabetes experience for most people.
Here's what's worth knowing: prediabetes is a real warning signal, but it's not a one-way door. What you do in this window genuinely matters.
What prediabetes actually is
MedlinePlus (NIH) defines prediabetes simply: your blood glucose is higher than normal, but not yet high enough to be called type 2 diabetes. The underlying driver is usually insulin resistance — your cells stop responding properly to insulin, so glucose builds up in your blood instead of getting used for energy.
The A1C test is the most common way to catch it. According to MedlinePlus's A1C page, the ranges look like this:
- Below 5.7% — normal
- 5.7–6.4% — prediabetes
- 6.5% and above — type 2 diabetes
If you're in that middle band, your doctor may recommend retesting every year. The risk isn't just diabetes — MedlinePlus notes that prediabetes also raises your risk for heart disease and stroke. It's a metabolic signal, not just a blood sugar number.
Why lifestyle changes aren't just "eat less, move more" advice
The evidence behind lifestyle intervention for prediabetes is unusually strong for the nutrition world. A 2020 study published in Nutrients (Amer et al.) followed Saudi adults with prediabetes through an 18-month lifestyle intervention and found that reversal of prediabetes — blood sugar returning to normal range — was achievable with sustained effort.
A 2026 study in Metabolism (Wang et al.) went further, showing that lifestyle intervention restored beta-cell function (the cells in your pancreas that produce insulin), reduced ectopic fat (fat stored in organs like the liver), and helped prevent progression to type 2 diabetes.
A 2023 paper in Nature Metabolism (Beals et al.) found that dietary weight loss already improved metabolic function in people with obesity and prediabetes — and that adding exercise on top of diet made those improvements even larger.
The mechanism makes sense: losing even modest body weight reduces the demand on your insulin system. Less visceral fat means your cells become more responsive to insulin again.
Exercise has its own independent effect
You don't have to wait until you've lost significant weight for exercise to help. A 2025 study in European Journal of Endocrinology (Mensberg et al.) found that high-intensity interval training improved insulin sensitivity in people with prediabetes — a direct, measurable effect on the core problem.
A 2024 systematic review and network meta-analysis in Frontiers in Endocrinology (Zhang et al.) compared different exercise types for prediabetes and found that multiple modalities — not just cardio — produced meaningful benefits.
What this means practically: you don't need a perfect program. Walking, resistance training, cycling, swimming — the research supports movement broadly. Consistency beats intensity, especially at the start.
What about GLP-1 medications?
This is a newer angle worth knowing about. A 2026 review in Primary Care Diabetes (Tentolouris et al.) examined the evidence for semaglutide and tirzepatide specifically in the context of prediabetes, finding evidence for both diabetes prevention and cardiovascular protection in this population.
This doesn't mean everyone with prediabetes needs a GLP-1 — that's a conversation for your prescriber based on your full picture. But it does mean the conversation is worth having if lifestyle changes alone aren't moving your numbers.
What this means for you
- Your A1C number is a starting point, not a verdict. According to MedlinePlus, lifestyle changes can delay or prevent type 2 diabetes — that window is real and it's open right now.
- Exercise helps your insulin sensitivity directly, not just through weight loss. According to Mensberg et al. in Eur J Endocrinol, even HIIT showed measurable improvement in people with prediabetes.
- If lifestyle alone isn't enough after sustained effort, ask your prescriber about the emerging evidence for GLP-1 medications in prediabetes — the research (Tentolouris et al.) is building.
Not medical advice. Talk to your prescriber about your specific numbers, risk factors, and what interventions make sense for you.
