Metabolic

HbA1c (Glycated Haemoglobin)

HbA1c measures the percentage of haemoglobin that has been glycated (bound to glucose) over the previous 2-3 months. Unlike fasting glucose, which captures a single point in time, HbA1c provides a longer-term picture of blood sugar control. It is the primary marker used to diagnose and monitor type 2 diabetes and pre-diabetes.

Optimal Ranges

Clinical (NHS) Range

20-42 mmol/mol (below 6.0%)

mmol/mol

Performance-Optimised Range

20-34 mmol/mol (below 5.4%)

mmol/mol

The clinical range defines what is considered medically “normal” — broad enough to cover 95% of the population. The performance range reflects where research and clinical experience suggest most people feel and function at their best.

Why It Matters

Why HbA1c matters for performance

Metabolic health is the foundation of performance. Elevated HbA1c — even within the pre-diabetic range — is associated with increased body fat storage, reduced energy, impaired recovery, and accelerated ageing. Many men who appear healthy and train regularly still have elevated HbA1c due to chronic stress, poor sleep, or high-carbohydrate diets. Catching metabolic dysfunction early provides a window to reverse it through lifestyle interventions before it becomes clinical diabetes.

Symptoms

Signs your levels may be off

Low / Deficiency

  • Not applicable — low HbA1c is generally favourable
  • Extremely low may indicate hypoglycaemia or blood disorders

High / Excess

  • Increased thirst and frequent urination
  • Persistent fatigue after meals
  • Difficulty losing body fat
  • Slow wound healing
  • Brain fog and poor concentration
  • Blurred vision

Dietary Sources

Foods that support HbA1c levels

Low-glycaemic vegetables (leafy greens, broccoli)Protein at every meal (slows glucose absorption)Healthy fats (olive oil, nuts, avocado)Fibre-rich foods (legumes, oats)Apple cider vinegar (before meals)Cinnamon (Ceylon variety)

Supplementation

Evidence-based supplementation approach

Berberine (500 mg 2-3x daily with meals) has robust evidence for improving insulin sensitivity, comparable to metformin in some studies. Chromium picolinate (200-1,000 mcg/day) may support glucose metabolism. Alpha-lipoic acid (300-600 mg/day) is an antioxidant that aids glucose uptake. However, the primary interventions for HbA1c are dietary — reducing refined carbohydrates, time-restricted eating, and post-meal walking.

Research

Key study

Efficacy of berberine in patients with type 2 diabetes mellitus

Yin J, Xing H, Ye J

Metabolism (2008)

DOI: 10.1016/j.metabol.2008.01.013

Related Biomarkers

Inflammation

hs-CRP (High-Sensitivity C-Reactive Protein)

Optimal: Below 1.0 mg/L

Hormones

Total Testosterone

Optimal: 20-30 nmol/L

Vitamins & Minerals

Magnesium (Serum)

Optimal: 0.85-1.0 mmol/L

Related Guides

Always Tired? The Blood Tests That Reveal Why

8 biomarkers behind fatigue

Complete Guide to Blood Tests for Men

What to test and why it matters

Test your HbA1c levels

HbA1c is included in the Helvy 50+ biomarker panel. Get your results in 5 days with a personalised protocol.

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This content is for educational purposes only and does not constitute medical advice. Your data suggests areas for optimisation, but any concerns should be discussed with a qualified healthcare professional. If your results flag values outside safe ranges, we recommend consulting your GP.